24
SIMULATION OF A 2.45 GHZ SQUARE MICROSTRlP PATCH ANI'ENNA USING MICROWAVE OFFICE 2000. Kua Jeak Thng Bachelor of Engineering with Honours 1l{ (Electronics and Computer Engineering) 7871.6 2004 K95 2004

SIMULATION OF GHZ SQUARE MICROSTRlP PATCH ANI

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SIMULATION OF A 245 GHZ SQUARE MICROSTRlP PATCH ANIENNA USING MICROWAVE OFFICE 2000

Kua Jeak Thng

Bachelor of Engineering with Honours 1l (Electronics and Computer Engineering) 78716

2004K95 2004

Universiti IVlalaysia Sarawak

R13a BORANG PENYERAHAN TESIS

Judul SI MULA nON OF A 245 GHZ SQUARFJ1ICllOSTRIP PATC H ANTE NNA USING MICROWAVE OFFICE 2000

SESI PENGAJ1AN 20032004

Saya K UA JEAK TONG (HtT RUF BESAR)

mengaku mcmbcnarkan teslS ini dlslmpan di Pusat Khidmat Maklumat Akademlk Unlvcrsiti MalaYSia Sarawak dengan syarat-syarat kegunaan seperti berikut

Hakmtllk kertas [)fojek adalah dl bawah nama penults melainkan pcnulisan scbagal projek bersama d~m dlblayal oleh UNIMAS hakmiliknya adal ah kepunyaan UNIMAS

2 Naskhah salinan di dalam bcntuk kertas atau mikro hanya boleh dibuat dengan kebenaran bert uhs dari pada pen u li s

J Pusat Khlum a( Maklumat Akademik UN [MAS dlbenarkan membuat sallnan untuk pengajian IHcnka

4 Kertas projck hanya boleh diterbitkan dengan kebenaran penulis Bayaran royalti ad~ l aJ menglkul kadar yang dlpersetUjUI kelak

5 Saya membenarkantldak membenarkan Perpustakaan membuat sallnan kelias [)1ojek in l sebagal badan pertukaran di lt1n tara Instltusl pengaJlan tlnggi

6 bull S tla tandakan (v)

SULIT (Mengandungi maklumat yang berdarjah kes el atn ~tan uau kcpcnllngilrl Malaysia scperti yang termaktub d dalam AKTA RA HS IA RASMI 1972)

TERHAD (Mengandungl maklumat TERHAD yang telah du cnt ukan oleh organlsasil bad an di mana penyelidlkan dijalankan)

TIDAI( TERHAD

~~Ieh (TANDATANGA N PENULlS) (TANDATANGA N PENY ELl A)

Alamat Totap NO 50 PA SAR M R KIS M ET HO NG PING ENG KILlLI 98500 SRI AMAN Nama Pen vehn SARAWAK

Takh 22 March 2004

CATATAN POIOn ( yang Ii dak berk enfl n Jib krrJs Pro)d 101 SC LIT alau TERI-IAD ~ da lamp illa rl SliI J daripillda pih( b~r ~UlSjl]torltar i~i

berkenaan delgul menyerlakan sekall lemJXlh kCTt ~ s proJcl 1m Vrl il ct dc h dilfl ~d~~i~1 SUI IT al au TERHAD

Laporan Projek Tahun Akhir berikul

Tajuk Simulation of A 245GHz Square Microstrip Patch antenna using Microwave Office 2000

Nama penuli s Kua Jeak Tong

Matrik 5138

telah dibaca dan disahkan o leh

Jai~ )1 ogt MClt ~inet Hong Ping Tarikh Penyelia

I)u~at hhidmul Mllklumal Aksdemlk U IVIRStll ML WSIA SARAVoAK

943W w anlJJhan

SIMULATION OF A 245 GHZ SQUARE MICROSTRJP PATCH

ANTE NA USING MICROWAVE OFFICE 2000

PKHIOMAT MAKlUMAT AKAOEMIK UMIMAS

1111111111111111111111111 1000126532

KUA JEAK TONG

This project is submitled in partial fulfillment of the requiremen ts for the degree of Bachelor of Engineeri ng with Hono rs

(Electro nic amp Computer Engineering)

Faculty o f Engineering t rVERSlTl MALA YSIA SARAW AK

2004

ACKNOLEDGEMENTS

The author would like to express my thankfulness to hi s Project Supe rvisoL Mr

Ki smet Hong Ping for hi s giving his prec ious guidance despite his tight schedule

Beside the author would like to ex press my gratitude to his fam ily for giving me all

supports throughout the years in UN IMAS Last but not least the autho r wo uld like

to thank to hi s friends fo r the ir helps coope rati on and supports to make thi s project

complete successfull y

Dedicated to my beloved fa mily and loved ones

ABSTRAK

Kajian ini membincangkan tentang kaedah-kaedah and simulasi untuk merekabentuk

antena jenis square microstrip patch dengan menggunakan peri sian MicroWave Office

2002 Beberapa ujikaji telah dibuat untuk mendapat keputusan yang paling optimum

Kajian ini berm ula dengan pembelajaran ke atas perbagai teori tentang isyarat gelombang

mikro jeni s-jenis antena dan sifat-sifatnya Kemudian diikuti dengan pengiraan untuk

panjang and lebar (dimensi) antena serta sai z untuk sell dalam kotak simulas i peri sian

sebelum bermuJanya simulasi Beberapa parameter yang penting perlu dikcnalpasti

antaranya ialah frequency operasi pemalar dieJektrik bahan dielektrik yang digunakan dan

sebagainya perlu dikenalpasti sebelum proses simulasi dan rekaan dijalankan Akbir sekali

semua keputusan-keputusan hasil daripada peri sian daJ am bentuk carta dan graf dianalisis

Kemudian diakbiri dengan pemilihan keputusan yang paling opti mum

ABSTRACT

This research descri bes the design and simulation of the sq uare Microstrip Patch

antenna usi ng Microwave Office 2002 and addit ional enhancement experimental to

come o ut with the optimum result The research started with the theoretical stud y

about the microwave signal type of antenna and cha racteristi c of the antenna Than

following by patch dime nsion calculation and cell size calculation in the simulation

box before the research invo lves the software simulation where severa l parameter

compri sing the operation freq uency dielectric constant substrate mate rial loss

tangent and etc were preset prior to the design of the antenna Finall y analys is is

make consist of the results from the Smith Chart VSWR Chal1 Return Loss Graph

and Impedance Graph with is generate by the Microwave Office 200 1 simulation

software and come out with the optimum result

II

CHAPTERS

ONE

TWO

TABLE OF CONTENTS

NO CONTENTS

ABSTRACT

ABSTRAK

TABLE OF CONTENTS

LIST OF TABLES

LIST OF FIGURES

11

12

13

INTRODUCTION

Background

Objective

Organization of the project report

2 1

22

LITERATURE REVIEW

Introduction

Basic type of antennas

221 Wire Antennas

222 Aperture Antennas

223 Microstrip antennas

224 Reflector Antennas

225 Len Antennas

III

PAG E

11

III

XI

xii

2

J

4

5

6

6

7

8

23 Definition of important Antennas parameters 9

231 Dielectric Constant 9

232 Bandwidth 10

23J Voltage Standing Wave Ratio (VSWR) II

234 Return Loss 12

235 Efficiency 12

236 Gain3D Pattem 13

237 Polarizati on 13

238 Impedance matching 14

24 Basic Characteristic of Microstri p ante nnas 14

25 Feeding Methods 15

2 6 Methods of Analysis 18

THREE METHODOLGY 19

3 1 Introduction 19

32 Flow chart 20

32 1 Specification of antenna design 2 1

322 Calculation of the patch size 22

323 Cell size calculation 23

324 Feeding in the substrate information 25

325 Patch size drawing 27

326 Simulation and Analysis 28

33 Selection criteria for the optimum antenna design 29

V I

~ - shy---- ---

FOUR

fIVE

41

42

4J

44

45

46

5 1

52

RESULTS AND ANA LYSIS

Si mulation I

Patch size modificat ion

Port Position

Difference feeding Method

Edge modification

Double dielectric substrate

CONCLUSION AND RECOMMENDATION

Conclusion

Recorrune ndations

References

Appendix

30

30

33

36

41

44

45

49

49

50

SI

53

x

- - ---

LIST OF TABLE

Tables Pages

41 Summari es of the results 32

42 Summaries resu lts of expanding patch size horizontall y 34

43 Summaries results of expanding patch size verti call y 34

44 Summaries results of reducing patch size hori zontall y 35

45 Summari es results of reduc ing patch size verticall y 36

46 Summaries results of moving port to left 37

47 Summaries results of moving port to right 38

48 Summaries results of moving port to left down 39

49 Summari es results of movi ng port to right down 39

410 Summari es results of movi ng port to center down 40

411 Summari es results of ex pand the line size 41

412 Summari es results of reduced the line size 42

4 13 Summaries resu lts of extended of line length 43

414 Summ ari es results of reduced of line length 43

415 Summar ies results o f patch sharp mod ification 44

416 Summaries result o f the two layer substrate antenna 46

XI

----- -

LIST OF FIGIlRES

Figures Pages

2 1 Wire antenna configuration S

22 Aperture anteJUla configuration 6

23 Rectangular and circu lar Microstrip antenna 7

24 Typical Reflector configurations 8

2S Basic type of lens configuration 9

26 Microstrip Antennas 14

27 Representative shapes of Microstrip patch elements IS

28 Typical feed s for Microstrip antennas 16

29 Equiva lent ci rcuit for typical feeds 17

3 1 Fl ow chart of the design procedures 20

32 Orientation of the Patch 24

33 Substrate Info nnati on for Enclosure 2shy

34 Substrate In formation for Dielectric Layer 26

3S Substrate Infomlation fo r Boundaries 27

36 Patc h wi th the correct dimen sion 28

41 VSWR chart of simulationl 30

42 Return Loss chart J I

43 Impedance chart 31

44 Expand patch size horizontally 33

4S Expand patch size verti cally 4

xu

~---

46 Reduced patch size horizonta ll y 35

47 Red uced patch size verti cally 36

48 Move port to the left 37

49 Move pOl1 to the rig ht 37

4 10 Move port to the left down 38

4 11 Move port to the right down 39

412 Move port to the center down 40

413 Ex pand the line size 41

414 Reduced the line s ize 42

415 Extend the line length 42

416 Reduced the line length 43

417 Edge modification 44

418 Two layer substrates elect romagnet ically coupled patch 45

419 Return Loss graph (optim um results) 47

420 VSWR (o ptimum resul ts) 47

421 Impedance Graph (optimum results) 48

5 1 Patch dimension (double substrate) 49

X IIl

11

CHAPTER 1

INTRODUCTION

Background

An antennas is defined by Webstars Dictionary as a usual ly metallic device

(as a rod or wire) for radiating or receiving radio waves[2J In the simpl er words is

the region of transi ti on between a guided wave and a free space wave It is a very

impoI1ant part or component in any communicati on system to transmit or receive the

signal to or from the free space And the difference type of system requires

difference type of the antenna

The antenna is a very common device that we can easil y found in this modem

world The television antennas radio antenna hand-phone antenna and many more

electrical and electronic devices are using it Antennas a lso used in many advance

communica tion system li ke radar fo r military propose airpoM surve illance and etc

Microstrip rectangle and square patch antennas have been study and fo und

suitable as single antenna element or for array applicatio n Mierostrip antennas have

several ad vantages compared to conventiona l microwave antennas Because of th is

many ap plications in between the frequency range of IOOMHz to IOOGHz are using

thi s type of antennas

Light weight low volume and thin profile confIguration is the malO

advantages for thi s type of antennas and there are fee l more advantages in state of

the fabrication cost simpler feed ing method easily design and made with dua l

frequency and polarization and required no cavity backing In the same time the

microstrip antennas also have an easier way to integrate with microwave integrated

ci rcuir

In this document experimenta l data is compiled on a difference feeding

method the probe feed and the feed line method The experiment or simulations are

made using Microwave offi ce 2000 CAD

Positioning of the probe feed (By adjustment the probe around some

important position) size and len g1h o f the feed line and shape of the an tennas (made

the cutting on the angle of square patc h antenna) are experimented and compared

The study and experimental also included in doub le or stacked dielectric substrate

Results from all the experiments then are compared and the design with the

best result are taken as the fmal result and used in the real antenna fabrication (this

state is for the future planning)

12 Objectives

The objectives of this project are as follow

I To analyze various type of feeding methods and apply in an an tenna design

II Simulate and design the microstrip antenna or Square patch antenna using

Microwave Office 2000

11 To define the bas ic characteristic and operation of an antenna

I V Simulate and design double or stacked dielectric substrate of the square patch

antenna

2

13 Organization of the project report

This report started with the idea to design a microstrip anterma and organized

in 5 chapters Chapter I describes the basic introduction of the microstrip antermas

application and the imponant of the antenna ad vantages compared with microwave

antennas and described about the objectives of the project

Chapter 2 deal s with the literature review of the project The descriptions

include the bas ic type of an termas some impOJ1ant definition for antennas parameters

like dielectric e lectric constant band width VSWR loss tangent and so for There

also described basic characteristic of the microstrip patch antennas and type of the

feeding methods for the antermas

The procedures to design started from the begirming of the patch dimension

calculation all the parameters apply in the simulation software (Microwave office

2000) and reach the final results which are di scussed in Chapter 3

The analysis is make consist of the results from the experiments the

compan son between various type of experiments and the se lection criteria for the

optimum antermas design are described in Chapter 4

Chapter 5 di scusses the conclusion of the project the fin~i result with is the

best from all the designs and recommendation is made to the project and the further

plarming to improved the project

3

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

Universiti IVlalaysia Sarawak

R13a BORANG PENYERAHAN TESIS

Judul SI MULA nON OF A 245 GHZ SQUARFJ1ICllOSTRIP PATC H ANTE NNA USING MICROWAVE OFFICE 2000

SESI PENGAJ1AN 20032004

Saya K UA JEAK TONG (HtT RUF BESAR)

mengaku mcmbcnarkan teslS ini dlslmpan di Pusat Khidmat Maklumat Akademlk Unlvcrsiti MalaYSia Sarawak dengan syarat-syarat kegunaan seperti berikut

Hakmtllk kertas [)fojek adalah dl bawah nama penults melainkan pcnulisan scbagal projek bersama d~m dlblayal oleh UNIMAS hakmiliknya adal ah kepunyaan UNIMAS

2 Naskhah salinan di dalam bcntuk kertas atau mikro hanya boleh dibuat dengan kebenaran bert uhs dari pada pen u li s

J Pusat Khlum a( Maklumat Akademik UN [MAS dlbenarkan membuat sallnan untuk pengajian IHcnka

4 Kertas projck hanya boleh diterbitkan dengan kebenaran penulis Bayaran royalti ad~ l aJ menglkul kadar yang dlpersetUjUI kelak

5 Saya membenarkantldak membenarkan Perpustakaan membuat sallnan kelias [)1ojek in l sebagal badan pertukaran di lt1n tara Instltusl pengaJlan tlnggi

6 bull S tla tandakan (v)

SULIT (Mengandungi maklumat yang berdarjah kes el atn ~tan uau kcpcnllngilrl Malaysia scperti yang termaktub d dalam AKTA RA HS IA RASMI 1972)

TERHAD (Mengandungl maklumat TERHAD yang telah du cnt ukan oleh organlsasil bad an di mana penyelidlkan dijalankan)

TIDAI( TERHAD

~~Ieh (TANDATANGA N PENULlS) (TANDATANGA N PENY ELl A)

Alamat Totap NO 50 PA SAR M R KIS M ET HO NG PING ENG KILlLI 98500 SRI AMAN Nama Pen vehn SARAWAK

Takh 22 March 2004

CATATAN POIOn ( yang Ii dak berk enfl n Jib krrJs Pro)d 101 SC LIT alau TERI-IAD ~ da lamp illa rl SliI J daripillda pih( b~r ~UlSjl]torltar i~i

berkenaan delgul menyerlakan sekall lemJXlh kCTt ~ s proJcl 1m Vrl il ct dc h dilfl ~d~~i~1 SUI IT al au TERHAD

Laporan Projek Tahun Akhir berikul

Tajuk Simulation of A 245GHz Square Microstrip Patch antenna using Microwave Office 2000

Nama penuli s Kua Jeak Tong

Matrik 5138

telah dibaca dan disahkan o leh

Jai~ )1 ogt MClt ~inet Hong Ping Tarikh Penyelia

I)u~at hhidmul Mllklumal Aksdemlk U IVIRStll ML WSIA SARAVoAK

943W w anlJJhan

SIMULATION OF A 245 GHZ SQUARE MICROSTRJP PATCH

ANTE NA USING MICROWAVE OFFICE 2000

PKHIOMAT MAKlUMAT AKAOEMIK UMIMAS

1111111111111111111111111 1000126532

KUA JEAK TONG

This project is submitled in partial fulfillment of the requiremen ts for the degree of Bachelor of Engineeri ng with Hono rs

(Electro nic amp Computer Engineering)

Faculty o f Engineering t rVERSlTl MALA YSIA SARAW AK

2004

ACKNOLEDGEMENTS

The author would like to express my thankfulness to hi s Project Supe rvisoL Mr

Ki smet Hong Ping for hi s giving his prec ious guidance despite his tight schedule

Beside the author would like to ex press my gratitude to his fam ily for giving me all

supports throughout the years in UN IMAS Last but not least the autho r wo uld like

to thank to hi s friends fo r the ir helps coope rati on and supports to make thi s project

complete successfull y

Dedicated to my beloved fa mily and loved ones

ABSTRAK

Kajian ini membincangkan tentang kaedah-kaedah and simulasi untuk merekabentuk

antena jenis square microstrip patch dengan menggunakan peri sian MicroWave Office

2002 Beberapa ujikaji telah dibuat untuk mendapat keputusan yang paling optimum

Kajian ini berm ula dengan pembelajaran ke atas perbagai teori tentang isyarat gelombang

mikro jeni s-jenis antena dan sifat-sifatnya Kemudian diikuti dengan pengiraan untuk

panjang and lebar (dimensi) antena serta sai z untuk sell dalam kotak simulas i peri sian

sebelum bermuJanya simulasi Beberapa parameter yang penting perlu dikcnalpasti

antaranya ialah frequency operasi pemalar dieJektrik bahan dielektrik yang digunakan dan

sebagainya perlu dikenalpasti sebelum proses simulasi dan rekaan dijalankan Akbir sekali

semua keputusan-keputusan hasil daripada peri sian daJ am bentuk carta dan graf dianalisis

Kemudian diakbiri dengan pemilihan keputusan yang paling opti mum

ABSTRACT

This research descri bes the design and simulation of the sq uare Microstrip Patch

antenna usi ng Microwave Office 2002 and addit ional enhancement experimental to

come o ut with the optimum result The research started with the theoretical stud y

about the microwave signal type of antenna and cha racteristi c of the antenna Than

following by patch dime nsion calculation and cell size calculation in the simulation

box before the research invo lves the software simulation where severa l parameter

compri sing the operation freq uency dielectric constant substrate mate rial loss

tangent and etc were preset prior to the design of the antenna Finall y analys is is

make consist of the results from the Smith Chart VSWR Chal1 Return Loss Graph

and Impedance Graph with is generate by the Microwave Office 200 1 simulation

software and come out with the optimum result

II

CHAPTERS

ONE

TWO

TABLE OF CONTENTS

NO CONTENTS

ABSTRACT

ABSTRAK

TABLE OF CONTENTS

LIST OF TABLES

LIST OF FIGURES

11

12

13

INTRODUCTION

Background

Objective

Organization of the project report

2 1

22

LITERATURE REVIEW

Introduction

Basic type of antennas

221 Wire Antennas

222 Aperture Antennas

223 Microstrip antennas

224 Reflector Antennas

225 Len Antennas

III

PAG E

11

III

XI

xii

2

J

4

5

6

6

7

8

23 Definition of important Antennas parameters 9

231 Dielectric Constant 9

232 Bandwidth 10

23J Voltage Standing Wave Ratio (VSWR) II

234 Return Loss 12

235 Efficiency 12

236 Gain3D Pattem 13

237 Polarizati on 13

238 Impedance matching 14

24 Basic Characteristic of Microstri p ante nnas 14

25 Feeding Methods 15

2 6 Methods of Analysis 18

THREE METHODOLGY 19

3 1 Introduction 19

32 Flow chart 20

32 1 Specification of antenna design 2 1

322 Calculation of the patch size 22

323 Cell size calculation 23

324 Feeding in the substrate information 25

325 Patch size drawing 27

326 Simulation and Analysis 28

33 Selection criteria for the optimum antenna design 29

V I

~ - shy---- ---

FOUR

fIVE

41

42

4J

44

45

46

5 1

52

RESULTS AND ANA LYSIS

Si mulation I

Patch size modificat ion

Port Position

Difference feeding Method

Edge modification

Double dielectric substrate

CONCLUSION AND RECOMMENDATION

Conclusion

Recorrune ndations

References

Appendix

30

30

33

36

41

44

45

49

49

50

SI

53

x

- - ---

LIST OF TABLE

Tables Pages

41 Summari es of the results 32

42 Summaries resu lts of expanding patch size horizontall y 34

43 Summaries results of expanding patch size verti call y 34

44 Summaries results of reducing patch size hori zontall y 35

45 Summari es results of reduc ing patch size verticall y 36

46 Summaries results of moving port to left 37

47 Summaries results of moving port to right 38

48 Summaries results of moving port to left down 39

49 Summari es results of movi ng port to right down 39

410 Summari es results of movi ng port to center down 40

411 Summari es results of ex pand the line size 41

412 Summari es results of reduced the line size 42

4 13 Summaries resu lts of extended of line length 43

414 Summ ari es results of reduced of line length 43

415 Summar ies results o f patch sharp mod ification 44

416 Summaries result o f the two layer substrate antenna 46

XI

----- -

LIST OF FIGIlRES

Figures Pages

2 1 Wire antenna configuration S

22 Aperture anteJUla configuration 6

23 Rectangular and circu lar Microstrip antenna 7

24 Typical Reflector configurations 8

2S Basic type of lens configuration 9

26 Microstrip Antennas 14

27 Representative shapes of Microstrip patch elements IS

28 Typical feed s for Microstrip antennas 16

29 Equiva lent ci rcuit for typical feeds 17

3 1 Fl ow chart of the design procedures 20

32 Orientation of the Patch 24

33 Substrate Info nnati on for Enclosure 2shy

34 Substrate In formation for Dielectric Layer 26

3S Substrate Infomlation fo r Boundaries 27

36 Patc h wi th the correct dimen sion 28

41 VSWR chart of simulationl 30

42 Return Loss chart J I

43 Impedance chart 31

44 Expand patch size horizontally 33

4S Expand patch size verti cally 4

xu

~---

46 Reduced patch size horizonta ll y 35

47 Red uced patch size verti cally 36

48 Move port to the left 37

49 Move pOl1 to the rig ht 37

4 10 Move port to the left down 38

4 11 Move port to the right down 39

412 Move port to the center down 40

413 Ex pand the line size 41

414 Reduced the line s ize 42

415 Extend the line length 42

416 Reduced the line length 43

417 Edge modification 44

418 Two layer substrates elect romagnet ically coupled patch 45

419 Return Loss graph (optim um results) 47

420 VSWR (o ptimum resul ts) 47

421 Impedance Graph (optimum results) 48

5 1 Patch dimension (double substrate) 49

X IIl

11

CHAPTER 1

INTRODUCTION

Background

An antennas is defined by Webstars Dictionary as a usual ly metallic device

(as a rod or wire) for radiating or receiving radio waves[2J In the simpl er words is

the region of transi ti on between a guided wave and a free space wave It is a very

impoI1ant part or component in any communicati on system to transmit or receive the

signal to or from the free space And the difference type of system requires

difference type of the antenna

The antenna is a very common device that we can easil y found in this modem

world The television antennas radio antenna hand-phone antenna and many more

electrical and electronic devices are using it Antennas a lso used in many advance

communica tion system li ke radar fo r military propose airpoM surve illance and etc

Microstrip rectangle and square patch antennas have been study and fo und

suitable as single antenna element or for array applicatio n Mierostrip antennas have

several ad vantages compared to conventiona l microwave antennas Because of th is

many ap plications in between the frequency range of IOOMHz to IOOGHz are using

thi s type of antennas

Light weight low volume and thin profile confIguration is the malO

advantages for thi s type of antennas and there are fee l more advantages in state of

the fabrication cost simpler feed ing method easily design and made with dua l

frequency and polarization and required no cavity backing In the same time the

microstrip antennas also have an easier way to integrate with microwave integrated

ci rcuir

In this document experimenta l data is compiled on a difference feeding

method the probe feed and the feed line method The experiment or simulations are

made using Microwave offi ce 2000 CAD

Positioning of the probe feed (By adjustment the probe around some

important position) size and len g1h o f the feed line and shape of the an tennas (made

the cutting on the angle of square patc h antenna) are experimented and compared

The study and experimental also included in doub le or stacked dielectric substrate

Results from all the experiments then are compared and the design with the

best result are taken as the fmal result and used in the real antenna fabrication (this

state is for the future planning)

12 Objectives

The objectives of this project are as follow

I To analyze various type of feeding methods and apply in an an tenna design

II Simulate and design the microstrip antenna or Square patch antenna using

Microwave Office 2000

11 To define the bas ic characteristic and operation of an antenna

I V Simulate and design double or stacked dielectric substrate of the square patch

antenna

2

13 Organization of the project report

This report started with the idea to design a microstrip anterma and organized

in 5 chapters Chapter I describes the basic introduction of the microstrip antermas

application and the imponant of the antenna ad vantages compared with microwave

antennas and described about the objectives of the project

Chapter 2 deal s with the literature review of the project The descriptions

include the bas ic type of an termas some impOJ1ant definition for antennas parameters

like dielectric e lectric constant band width VSWR loss tangent and so for There

also described basic characteristic of the microstrip patch antennas and type of the

feeding methods for the antermas

The procedures to design started from the begirming of the patch dimension

calculation all the parameters apply in the simulation software (Microwave office

2000) and reach the final results which are di scussed in Chapter 3

The analysis is make consist of the results from the experiments the

compan son between various type of experiments and the se lection criteria for the

optimum antermas design are described in Chapter 4

Chapter 5 di scusses the conclusion of the project the fin~i result with is the

best from all the designs and recommendation is made to the project and the further

plarming to improved the project

3

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

Laporan Projek Tahun Akhir berikul

Tajuk Simulation of A 245GHz Square Microstrip Patch antenna using Microwave Office 2000

Nama penuli s Kua Jeak Tong

Matrik 5138

telah dibaca dan disahkan o leh

Jai~ )1 ogt MClt ~inet Hong Ping Tarikh Penyelia

I)u~at hhidmul Mllklumal Aksdemlk U IVIRStll ML WSIA SARAVoAK

943W w anlJJhan

SIMULATION OF A 245 GHZ SQUARE MICROSTRJP PATCH

ANTE NA USING MICROWAVE OFFICE 2000

PKHIOMAT MAKlUMAT AKAOEMIK UMIMAS

1111111111111111111111111 1000126532

KUA JEAK TONG

This project is submitled in partial fulfillment of the requiremen ts for the degree of Bachelor of Engineeri ng with Hono rs

(Electro nic amp Computer Engineering)

Faculty o f Engineering t rVERSlTl MALA YSIA SARAW AK

2004

ACKNOLEDGEMENTS

The author would like to express my thankfulness to hi s Project Supe rvisoL Mr

Ki smet Hong Ping for hi s giving his prec ious guidance despite his tight schedule

Beside the author would like to ex press my gratitude to his fam ily for giving me all

supports throughout the years in UN IMAS Last but not least the autho r wo uld like

to thank to hi s friends fo r the ir helps coope rati on and supports to make thi s project

complete successfull y

Dedicated to my beloved fa mily and loved ones

ABSTRAK

Kajian ini membincangkan tentang kaedah-kaedah and simulasi untuk merekabentuk

antena jenis square microstrip patch dengan menggunakan peri sian MicroWave Office

2002 Beberapa ujikaji telah dibuat untuk mendapat keputusan yang paling optimum

Kajian ini berm ula dengan pembelajaran ke atas perbagai teori tentang isyarat gelombang

mikro jeni s-jenis antena dan sifat-sifatnya Kemudian diikuti dengan pengiraan untuk

panjang and lebar (dimensi) antena serta sai z untuk sell dalam kotak simulas i peri sian

sebelum bermuJanya simulasi Beberapa parameter yang penting perlu dikcnalpasti

antaranya ialah frequency operasi pemalar dieJektrik bahan dielektrik yang digunakan dan

sebagainya perlu dikenalpasti sebelum proses simulasi dan rekaan dijalankan Akbir sekali

semua keputusan-keputusan hasil daripada peri sian daJ am bentuk carta dan graf dianalisis

Kemudian diakbiri dengan pemilihan keputusan yang paling opti mum

ABSTRACT

This research descri bes the design and simulation of the sq uare Microstrip Patch

antenna usi ng Microwave Office 2002 and addit ional enhancement experimental to

come o ut with the optimum result The research started with the theoretical stud y

about the microwave signal type of antenna and cha racteristi c of the antenna Than

following by patch dime nsion calculation and cell size calculation in the simulation

box before the research invo lves the software simulation where severa l parameter

compri sing the operation freq uency dielectric constant substrate mate rial loss

tangent and etc were preset prior to the design of the antenna Finall y analys is is

make consist of the results from the Smith Chart VSWR Chal1 Return Loss Graph

and Impedance Graph with is generate by the Microwave Office 200 1 simulation

software and come out with the optimum result

II

CHAPTERS

ONE

TWO

TABLE OF CONTENTS

NO CONTENTS

ABSTRACT

ABSTRAK

TABLE OF CONTENTS

LIST OF TABLES

LIST OF FIGURES

11

12

13

INTRODUCTION

Background

Objective

Organization of the project report

2 1

22

LITERATURE REVIEW

Introduction

Basic type of antennas

221 Wire Antennas

222 Aperture Antennas

223 Microstrip antennas

224 Reflector Antennas

225 Len Antennas

III

PAG E

11

III

XI

xii

2

J

4

5

6

6

7

8

23 Definition of important Antennas parameters 9

231 Dielectric Constant 9

232 Bandwidth 10

23J Voltage Standing Wave Ratio (VSWR) II

234 Return Loss 12

235 Efficiency 12

236 Gain3D Pattem 13

237 Polarizati on 13

238 Impedance matching 14

24 Basic Characteristic of Microstri p ante nnas 14

25 Feeding Methods 15

2 6 Methods of Analysis 18

THREE METHODOLGY 19

3 1 Introduction 19

32 Flow chart 20

32 1 Specification of antenna design 2 1

322 Calculation of the patch size 22

323 Cell size calculation 23

324 Feeding in the substrate information 25

325 Patch size drawing 27

326 Simulation and Analysis 28

33 Selection criteria for the optimum antenna design 29

V I

~ - shy---- ---

FOUR

fIVE

41

42

4J

44

45

46

5 1

52

RESULTS AND ANA LYSIS

Si mulation I

Patch size modificat ion

Port Position

Difference feeding Method

Edge modification

Double dielectric substrate

CONCLUSION AND RECOMMENDATION

Conclusion

Recorrune ndations

References

Appendix

30

30

33

36

41

44

45

49

49

50

SI

53

x

- - ---

LIST OF TABLE

Tables Pages

41 Summari es of the results 32

42 Summaries resu lts of expanding patch size horizontall y 34

43 Summaries results of expanding patch size verti call y 34

44 Summaries results of reducing patch size hori zontall y 35

45 Summari es results of reduc ing patch size verticall y 36

46 Summaries results of moving port to left 37

47 Summaries results of moving port to right 38

48 Summaries results of moving port to left down 39

49 Summari es results of movi ng port to right down 39

410 Summari es results of movi ng port to center down 40

411 Summari es results of ex pand the line size 41

412 Summari es results of reduced the line size 42

4 13 Summaries resu lts of extended of line length 43

414 Summ ari es results of reduced of line length 43

415 Summar ies results o f patch sharp mod ification 44

416 Summaries result o f the two layer substrate antenna 46

XI

----- -

LIST OF FIGIlRES

Figures Pages

2 1 Wire antenna configuration S

22 Aperture anteJUla configuration 6

23 Rectangular and circu lar Microstrip antenna 7

24 Typical Reflector configurations 8

2S Basic type of lens configuration 9

26 Microstrip Antennas 14

27 Representative shapes of Microstrip patch elements IS

28 Typical feed s for Microstrip antennas 16

29 Equiva lent ci rcuit for typical feeds 17

3 1 Fl ow chart of the design procedures 20

32 Orientation of the Patch 24

33 Substrate Info nnati on for Enclosure 2shy

34 Substrate In formation for Dielectric Layer 26

3S Substrate Infomlation fo r Boundaries 27

36 Patc h wi th the correct dimen sion 28

41 VSWR chart of simulationl 30

42 Return Loss chart J I

43 Impedance chart 31

44 Expand patch size horizontally 33

4S Expand patch size verti cally 4

xu

~---

46 Reduced patch size horizonta ll y 35

47 Red uced patch size verti cally 36

48 Move port to the left 37

49 Move pOl1 to the rig ht 37

4 10 Move port to the left down 38

4 11 Move port to the right down 39

412 Move port to the center down 40

413 Ex pand the line size 41

414 Reduced the line s ize 42

415 Extend the line length 42

416 Reduced the line length 43

417 Edge modification 44

418 Two layer substrates elect romagnet ically coupled patch 45

419 Return Loss graph (optim um results) 47

420 VSWR (o ptimum resul ts) 47

421 Impedance Graph (optimum results) 48

5 1 Patch dimension (double substrate) 49

X IIl

11

CHAPTER 1

INTRODUCTION

Background

An antennas is defined by Webstars Dictionary as a usual ly metallic device

(as a rod or wire) for radiating or receiving radio waves[2J In the simpl er words is

the region of transi ti on between a guided wave and a free space wave It is a very

impoI1ant part or component in any communicati on system to transmit or receive the

signal to or from the free space And the difference type of system requires

difference type of the antenna

The antenna is a very common device that we can easil y found in this modem

world The television antennas radio antenna hand-phone antenna and many more

electrical and electronic devices are using it Antennas a lso used in many advance

communica tion system li ke radar fo r military propose airpoM surve illance and etc

Microstrip rectangle and square patch antennas have been study and fo und

suitable as single antenna element or for array applicatio n Mierostrip antennas have

several ad vantages compared to conventiona l microwave antennas Because of th is

many ap plications in between the frequency range of IOOMHz to IOOGHz are using

thi s type of antennas

Light weight low volume and thin profile confIguration is the malO

advantages for thi s type of antennas and there are fee l more advantages in state of

the fabrication cost simpler feed ing method easily design and made with dua l

frequency and polarization and required no cavity backing In the same time the

microstrip antennas also have an easier way to integrate with microwave integrated

ci rcuir

In this document experimenta l data is compiled on a difference feeding

method the probe feed and the feed line method The experiment or simulations are

made using Microwave offi ce 2000 CAD

Positioning of the probe feed (By adjustment the probe around some

important position) size and len g1h o f the feed line and shape of the an tennas (made

the cutting on the angle of square patc h antenna) are experimented and compared

The study and experimental also included in doub le or stacked dielectric substrate

Results from all the experiments then are compared and the design with the

best result are taken as the fmal result and used in the real antenna fabrication (this

state is for the future planning)

12 Objectives

The objectives of this project are as follow

I To analyze various type of feeding methods and apply in an an tenna design

II Simulate and design the microstrip antenna or Square patch antenna using

Microwave Office 2000

11 To define the bas ic characteristic and operation of an antenna

I V Simulate and design double or stacked dielectric substrate of the square patch

antenna

2

13 Organization of the project report

This report started with the idea to design a microstrip anterma and organized

in 5 chapters Chapter I describes the basic introduction of the microstrip antermas

application and the imponant of the antenna ad vantages compared with microwave

antennas and described about the objectives of the project

Chapter 2 deal s with the literature review of the project The descriptions

include the bas ic type of an termas some impOJ1ant definition for antennas parameters

like dielectric e lectric constant band width VSWR loss tangent and so for There

also described basic characteristic of the microstrip patch antennas and type of the

feeding methods for the antermas

The procedures to design started from the begirming of the patch dimension

calculation all the parameters apply in the simulation software (Microwave office

2000) and reach the final results which are di scussed in Chapter 3

The analysis is make consist of the results from the experiments the

compan son between various type of experiments and the se lection criteria for the

optimum antermas design are described in Chapter 4

Chapter 5 di scusses the conclusion of the project the fin~i result with is the

best from all the designs and recommendation is made to the project and the further

plarming to improved the project

3

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

I)u~at hhidmul Mllklumal Aksdemlk U IVIRStll ML WSIA SARAVoAK

943W w anlJJhan

SIMULATION OF A 245 GHZ SQUARE MICROSTRJP PATCH

ANTE NA USING MICROWAVE OFFICE 2000

PKHIOMAT MAKlUMAT AKAOEMIK UMIMAS

1111111111111111111111111 1000126532

KUA JEAK TONG

This project is submitled in partial fulfillment of the requiremen ts for the degree of Bachelor of Engineeri ng with Hono rs

(Electro nic amp Computer Engineering)

Faculty o f Engineering t rVERSlTl MALA YSIA SARAW AK

2004

ACKNOLEDGEMENTS

The author would like to express my thankfulness to hi s Project Supe rvisoL Mr

Ki smet Hong Ping for hi s giving his prec ious guidance despite his tight schedule

Beside the author would like to ex press my gratitude to his fam ily for giving me all

supports throughout the years in UN IMAS Last but not least the autho r wo uld like

to thank to hi s friends fo r the ir helps coope rati on and supports to make thi s project

complete successfull y

Dedicated to my beloved fa mily and loved ones

ABSTRAK

Kajian ini membincangkan tentang kaedah-kaedah and simulasi untuk merekabentuk

antena jenis square microstrip patch dengan menggunakan peri sian MicroWave Office

2002 Beberapa ujikaji telah dibuat untuk mendapat keputusan yang paling optimum

Kajian ini berm ula dengan pembelajaran ke atas perbagai teori tentang isyarat gelombang

mikro jeni s-jenis antena dan sifat-sifatnya Kemudian diikuti dengan pengiraan untuk

panjang and lebar (dimensi) antena serta sai z untuk sell dalam kotak simulas i peri sian

sebelum bermuJanya simulasi Beberapa parameter yang penting perlu dikcnalpasti

antaranya ialah frequency operasi pemalar dieJektrik bahan dielektrik yang digunakan dan

sebagainya perlu dikenalpasti sebelum proses simulasi dan rekaan dijalankan Akbir sekali

semua keputusan-keputusan hasil daripada peri sian daJ am bentuk carta dan graf dianalisis

Kemudian diakbiri dengan pemilihan keputusan yang paling opti mum

ABSTRACT

This research descri bes the design and simulation of the sq uare Microstrip Patch

antenna usi ng Microwave Office 2002 and addit ional enhancement experimental to

come o ut with the optimum result The research started with the theoretical stud y

about the microwave signal type of antenna and cha racteristi c of the antenna Than

following by patch dime nsion calculation and cell size calculation in the simulation

box before the research invo lves the software simulation where severa l parameter

compri sing the operation freq uency dielectric constant substrate mate rial loss

tangent and etc were preset prior to the design of the antenna Finall y analys is is

make consist of the results from the Smith Chart VSWR Chal1 Return Loss Graph

and Impedance Graph with is generate by the Microwave Office 200 1 simulation

software and come out with the optimum result

II

CHAPTERS

ONE

TWO

TABLE OF CONTENTS

NO CONTENTS

ABSTRACT

ABSTRAK

TABLE OF CONTENTS

LIST OF TABLES

LIST OF FIGURES

11

12

13

INTRODUCTION

Background

Objective

Organization of the project report

2 1

22

LITERATURE REVIEW

Introduction

Basic type of antennas

221 Wire Antennas

222 Aperture Antennas

223 Microstrip antennas

224 Reflector Antennas

225 Len Antennas

III

PAG E

11

III

XI

xii

2

J

4

5

6

6

7

8

23 Definition of important Antennas parameters 9

231 Dielectric Constant 9

232 Bandwidth 10

23J Voltage Standing Wave Ratio (VSWR) II

234 Return Loss 12

235 Efficiency 12

236 Gain3D Pattem 13

237 Polarizati on 13

238 Impedance matching 14

24 Basic Characteristic of Microstri p ante nnas 14

25 Feeding Methods 15

2 6 Methods of Analysis 18

THREE METHODOLGY 19

3 1 Introduction 19

32 Flow chart 20

32 1 Specification of antenna design 2 1

322 Calculation of the patch size 22

323 Cell size calculation 23

324 Feeding in the substrate information 25

325 Patch size drawing 27

326 Simulation and Analysis 28

33 Selection criteria for the optimum antenna design 29

V I

~ - shy---- ---

FOUR

fIVE

41

42

4J

44

45

46

5 1

52

RESULTS AND ANA LYSIS

Si mulation I

Patch size modificat ion

Port Position

Difference feeding Method

Edge modification

Double dielectric substrate

CONCLUSION AND RECOMMENDATION

Conclusion

Recorrune ndations

References

Appendix

30

30

33

36

41

44

45

49

49

50

SI

53

x

- - ---

LIST OF TABLE

Tables Pages

41 Summari es of the results 32

42 Summaries resu lts of expanding patch size horizontall y 34

43 Summaries results of expanding patch size verti call y 34

44 Summaries results of reducing patch size hori zontall y 35

45 Summari es results of reduc ing patch size verticall y 36

46 Summaries results of moving port to left 37

47 Summaries results of moving port to right 38

48 Summaries results of moving port to left down 39

49 Summari es results of movi ng port to right down 39

410 Summari es results of movi ng port to center down 40

411 Summari es results of ex pand the line size 41

412 Summari es results of reduced the line size 42

4 13 Summaries resu lts of extended of line length 43

414 Summ ari es results of reduced of line length 43

415 Summar ies results o f patch sharp mod ification 44

416 Summaries result o f the two layer substrate antenna 46

XI

----- -

LIST OF FIGIlRES

Figures Pages

2 1 Wire antenna configuration S

22 Aperture anteJUla configuration 6

23 Rectangular and circu lar Microstrip antenna 7

24 Typical Reflector configurations 8

2S Basic type of lens configuration 9

26 Microstrip Antennas 14

27 Representative shapes of Microstrip patch elements IS

28 Typical feed s for Microstrip antennas 16

29 Equiva lent ci rcuit for typical feeds 17

3 1 Fl ow chart of the design procedures 20

32 Orientation of the Patch 24

33 Substrate Info nnati on for Enclosure 2shy

34 Substrate In formation for Dielectric Layer 26

3S Substrate Infomlation fo r Boundaries 27

36 Patc h wi th the correct dimen sion 28

41 VSWR chart of simulationl 30

42 Return Loss chart J I

43 Impedance chart 31

44 Expand patch size horizontally 33

4S Expand patch size verti cally 4

xu

~---

46 Reduced patch size horizonta ll y 35

47 Red uced patch size verti cally 36

48 Move port to the left 37

49 Move pOl1 to the rig ht 37

4 10 Move port to the left down 38

4 11 Move port to the right down 39

412 Move port to the center down 40

413 Ex pand the line size 41

414 Reduced the line s ize 42

415 Extend the line length 42

416 Reduced the line length 43

417 Edge modification 44

418 Two layer substrates elect romagnet ically coupled patch 45

419 Return Loss graph (optim um results) 47

420 VSWR (o ptimum resul ts) 47

421 Impedance Graph (optimum results) 48

5 1 Patch dimension (double substrate) 49

X IIl

11

CHAPTER 1

INTRODUCTION

Background

An antennas is defined by Webstars Dictionary as a usual ly metallic device

(as a rod or wire) for radiating or receiving radio waves[2J In the simpl er words is

the region of transi ti on between a guided wave and a free space wave It is a very

impoI1ant part or component in any communicati on system to transmit or receive the

signal to or from the free space And the difference type of system requires

difference type of the antenna

The antenna is a very common device that we can easil y found in this modem

world The television antennas radio antenna hand-phone antenna and many more

electrical and electronic devices are using it Antennas a lso used in many advance

communica tion system li ke radar fo r military propose airpoM surve illance and etc

Microstrip rectangle and square patch antennas have been study and fo und

suitable as single antenna element or for array applicatio n Mierostrip antennas have

several ad vantages compared to conventiona l microwave antennas Because of th is

many ap plications in between the frequency range of IOOMHz to IOOGHz are using

thi s type of antennas

Light weight low volume and thin profile confIguration is the malO

advantages for thi s type of antennas and there are fee l more advantages in state of

the fabrication cost simpler feed ing method easily design and made with dua l

frequency and polarization and required no cavity backing In the same time the

microstrip antennas also have an easier way to integrate with microwave integrated

ci rcuir

In this document experimenta l data is compiled on a difference feeding

method the probe feed and the feed line method The experiment or simulations are

made using Microwave offi ce 2000 CAD

Positioning of the probe feed (By adjustment the probe around some

important position) size and len g1h o f the feed line and shape of the an tennas (made

the cutting on the angle of square patc h antenna) are experimented and compared

The study and experimental also included in doub le or stacked dielectric substrate

Results from all the experiments then are compared and the design with the

best result are taken as the fmal result and used in the real antenna fabrication (this

state is for the future planning)

12 Objectives

The objectives of this project are as follow

I To analyze various type of feeding methods and apply in an an tenna design

II Simulate and design the microstrip antenna or Square patch antenna using

Microwave Office 2000

11 To define the bas ic characteristic and operation of an antenna

I V Simulate and design double or stacked dielectric substrate of the square patch

antenna

2

13 Organization of the project report

This report started with the idea to design a microstrip anterma and organized

in 5 chapters Chapter I describes the basic introduction of the microstrip antermas

application and the imponant of the antenna ad vantages compared with microwave

antennas and described about the objectives of the project

Chapter 2 deal s with the literature review of the project The descriptions

include the bas ic type of an termas some impOJ1ant definition for antennas parameters

like dielectric e lectric constant band width VSWR loss tangent and so for There

also described basic characteristic of the microstrip patch antennas and type of the

feeding methods for the antermas

The procedures to design started from the begirming of the patch dimension

calculation all the parameters apply in the simulation software (Microwave office

2000) and reach the final results which are di scussed in Chapter 3

The analysis is make consist of the results from the experiments the

compan son between various type of experiments and the se lection criteria for the

optimum antermas design are described in Chapter 4

Chapter 5 di scusses the conclusion of the project the fin~i result with is the

best from all the designs and recommendation is made to the project and the further

plarming to improved the project

3

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

ACKNOLEDGEMENTS

The author would like to express my thankfulness to hi s Project Supe rvisoL Mr

Ki smet Hong Ping for hi s giving his prec ious guidance despite his tight schedule

Beside the author would like to ex press my gratitude to his fam ily for giving me all

supports throughout the years in UN IMAS Last but not least the autho r wo uld like

to thank to hi s friends fo r the ir helps coope rati on and supports to make thi s project

complete successfull y

Dedicated to my beloved fa mily and loved ones

ABSTRAK

Kajian ini membincangkan tentang kaedah-kaedah and simulasi untuk merekabentuk

antena jenis square microstrip patch dengan menggunakan peri sian MicroWave Office

2002 Beberapa ujikaji telah dibuat untuk mendapat keputusan yang paling optimum

Kajian ini berm ula dengan pembelajaran ke atas perbagai teori tentang isyarat gelombang

mikro jeni s-jenis antena dan sifat-sifatnya Kemudian diikuti dengan pengiraan untuk

panjang and lebar (dimensi) antena serta sai z untuk sell dalam kotak simulas i peri sian

sebelum bermuJanya simulasi Beberapa parameter yang penting perlu dikcnalpasti

antaranya ialah frequency operasi pemalar dieJektrik bahan dielektrik yang digunakan dan

sebagainya perlu dikenalpasti sebelum proses simulasi dan rekaan dijalankan Akbir sekali

semua keputusan-keputusan hasil daripada peri sian daJ am bentuk carta dan graf dianalisis

Kemudian diakbiri dengan pemilihan keputusan yang paling opti mum

ABSTRACT

This research descri bes the design and simulation of the sq uare Microstrip Patch

antenna usi ng Microwave Office 2002 and addit ional enhancement experimental to

come o ut with the optimum result The research started with the theoretical stud y

about the microwave signal type of antenna and cha racteristi c of the antenna Than

following by patch dime nsion calculation and cell size calculation in the simulation

box before the research invo lves the software simulation where severa l parameter

compri sing the operation freq uency dielectric constant substrate mate rial loss

tangent and etc were preset prior to the design of the antenna Finall y analys is is

make consist of the results from the Smith Chart VSWR Chal1 Return Loss Graph

and Impedance Graph with is generate by the Microwave Office 200 1 simulation

software and come out with the optimum result

II

CHAPTERS

ONE

TWO

TABLE OF CONTENTS

NO CONTENTS

ABSTRACT

ABSTRAK

TABLE OF CONTENTS

LIST OF TABLES

LIST OF FIGURES

11

12

13

INTRODUCTION

Background

Objective

Organization of the project report

2 1

22

LITERATURE REVIEW

Introduction

Basic type of antennas

221 Wire Antennas

222 Aperture Antennas

223 Microstrip antennas

224 Reflector Antennas

225 Len Antennas

III

PAG E

11

III

XI

xii

2

J

4

5

6

6

7

8

23 Definition of important Antennas parameters 9

231 Dielectric Constant 9

232 Bandwidth 10

23J Voltage Standing Wave Ratio (VSWR) II

234 Return Loss 12

235 Efficiency 12

236 Gain3D Pattem 13

237 Polarizati on 13

238 Impedance matching 14

24 Basic Characteristic of Microstri p ante nnas 14

25 Feeding Methods 15

2 6 Methods of Analysis 18

THREE METHODOLGY 19

3 1 Introduction 19

32 Flow chart 20

32 1 Specification of antenna design 2 1

322 Calculation of the patch size 22

323 Cell size calculation 23

324 Feeding in the substrate information 25

325 Patch size drawing 27

326 Simulation and Analysis 28

33 Selection criteria for the optimum antenna design 29

V I

~ - shy---- ---

FOUR

fIVE

41

42

4J

44

45

46

5 1

52

RESULTS AND ANA LYSIS

Si mulation I

Patch size modificat ion

Port Position

Difference feeding Method

Edge modification

Double dielectric substrate

CONCLUSION AND RECOMMENDATION

Conclusion

Recorrune ndations

References

Appendix

30

30

33

36

41

44

45

49

49

50

SI

53

x

- - ---

LIST OF TABLE

Tables Pages

41 Summari es of the results 32

42 Summaries resu lts of expanding patch size horizontall y 34

43 Summaries results of expanding patch size verti call y 34

44 Summaries results of reducing patch size hori zontall y 35

45 Summari es results of reduc ing patch size verticall y 36

46 Summaries results of moving port to left 37

47 Summaries results of moving port to right 38

48 Summaries results of moving port to left down 39

49 Summari es results of movi ng port to right down 39

410 Summari es results of movi ng port to center down 40

411 Summari es results of ex pand the line size 41

412 Summari es results of reduced the line size 42

4 13 Summaries resu lts of extended of line length 43

414 Summ ari es results of reduced of line length 43

415 Summar ies results o f patch sharp mod ification 44

416 Summaries result o f the two layer substrate antenna 46

XI

----- -

LIST OF FIGIlRES

Figures Pages

2 1 Wire antenna configuration S

22 Aperture anteJUla configuration 6

23 Rectangular and circu lar Microstrip antenna 7

24 Typical Reflector configurations 8

2S Basic type of lens configuration 9

26 Microstrip Antennas 14

27 Representative shapes of Microstrip patch elements IS

28 Typical feed s for Microstrip antennas 16

29 Equiva lent ci rcuit for typical feeds 17

3 1 Fl ow chart of the design procedures 20

32 Orientation of the Patch 24

33 Substrate Info nnati on for Enclosure 2shy

34 Substrate In formation for Dielectric Layer 26

3S Substrate Infomlation fo r Boundaries 27

36 Patc h wi th the correct dimen sion 28

41 VSWR chart of simulationl 30

42 Return Loss chart J I

43 Impedance chart 31

44 Expand patch size horizontally 33

4S Expand patch size verti cally 4

xu

~---

46 Reduced patch size horizonta ll y 35

47 Red uced patch size verti cally 36

48 Move port to the left 37

49 Move pOl1 to the rig ht 37

4 10 Move port to the left down 38

4 11 Move port to the right down 39

412 Move port to the center down 40

413 Ex pand the line size 41

414 Reduced the line s ize 42

415 Extend the line length 42

416 Reduced the line length 43

417 Edge modification 44

418 Two layer substrates elect romagnet ically coupled patch 45

419 Return Loss graph (optim um results) 47

420 VSWR (o ptimum resul ts) 47

421 Impedance Graph (optimum results) 48

5 1 Patch dimension (double substrate) 49

X IIl

11

CHAPTER 1

INTRODUCTION

Background

An antennas is defined by Webstars Dictionary as a usual ly metallic device

(as a rod or wire) for radiating or receiving radio waves[2J In the simpl er words is

the region of transi ti on between a guided wave and a free space wave It is a very

impoI1ant part or component in any communicati on system to transmit or receive the

signal to or from the free space And the difference type of system requires

difference type of the antenna

The antenna is a very common device that we can easil y found in this modem

world The television antennas radio antenna hand-phone antenna and many more

electrical and electronic devices are using it Antennas a lso used in many advance

communica tion system li ke radar fo r military propose airpoM surve illance and etc

Microstrip rectangle and square patch antennas have been study and fo und

suitable as single antenna element or for array applicatio n Mierostrip antennas have

several ad vantages compared to conventiona l microwave antennas Because of th is

many ap plications in between the frequency range of IOOMHz to IOOGHz are using

thi s type of antennas

Light weight low volume and thin profile confIguration is the malO

advantages for thi s type of antennas and there are fee l more advantages in state of

the fabrication cost simpler feed ing method easily design and made with dua l

frequency and polarization and required no cavity backing In the same time the

microstrip antennas also have an easier way to integrate with microwave integrated

ci rcuir

In this document experimenta l data is compiled on a difference feeding

method the probe feed and the feed line method The experiment or simulations are

made using Microwave offi ce 2000 CAD

Positioning of the probe feed (By adjustment the probe around some

important position) size and len g1h o f the feed line and shape of the an tennas (made

the cutting on the angle of square patc h antenna) are experimented and compared

The study and experimental also included in doub le or stacked dielectric substrate

Results from all the experiments then are compared and the design with the

best result are taken as the fmal result and used in the real antenna fabrication (this

state is for the future planning)

12 Objectives

The objectives of this project are as follow

I To analyze various type of feeding methods and apply in an an tenna design

II Simulate and design the microstrip antenna or Square patch antenna using

Microwave Office 2000

11 To define the bas ic characteristic and operation of an antenna

I V Simulate and design double or stacked dielectric substrate of the square patch

antenna

2

13 Organization of the project report

This report started with the idea to design a microstrip anterma and organized

in 5 chapters Chapter I describes the basic introduction of the microstrip antermas

application and the imponant of the antenna ad vantages compared with microwave

antennas and described about the objectives of the project

Chapter 2 deal s with the literature review of the project The descriptions

include the bas ic type of an termas some impOJ1ant definition for antennas parameters

like dielectric e lectric constant band width VSWR loss tangent and so for There

also described basic characteristic of the microstrip patch antennas and type of the

feeding methods for the antermas

The procedures to design started from the begirming of the patch dimension

calculation all the parameters apply in the simulation software (Microwave office

2000) and reach the final results which are di scussed in Chapter 3

The analysis is make consist of the results from the experiments the

compan son between various type of experiments and the se lection criteria for the

optimum antermas design are described in Chapter 4

Chapter 5 di scusses the conclusion of the project the fin~i result with is the

best from all the designs and recommendation is made to the project and the further

plarming to improved the project

3

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

Dedicated to my beloved fa mily and loved ones

ABSTRAK

Kajian ini membincangkan tentang kaedah-kaedah and simulasi untuk merekabentuk

antena jenis square microstrip patch dengan menggunakan peri sian MicroWave Office

2002 Beberapa ujikaji telah dibuat untuk mendapat keputusan yang paling optimum

Kajian ini berm ula dengan pembelajaran ke atas perbagai teori tentang isyarat gelombang

mikro jeni s-jenis antena dan sifat-sifatnya Kemudian diikuti dengan pengiraan untuk

panjang and lebar (dimensi) antena serta sai z untuk sell dalam kotak simulas i peri sian

sebelum bermuJanya simulasi Beberapa parameter yang penting perlu dikcnalpasti

antaranya ialah frequency operasi pemalar dieJektrik bahan dielektrik yang digunakan dan

sebagainya perlu dikenalpasti sebelum proses simulasi dan rekaan dijalankan Akbir sekali

semua keputusan-keputusan hasil daripada peri sian daJ am bentuk carta dan graf dianalisis

Kemudian diakbiri dengan pemilihan keputusan yang paling opti mum

ABSTRACT

This research descri bes the design and simulation of the sq uare Microstrip Patch

antenna usi ng Microwave Office 2002 and addit ional enhancement experimental to

come o ut with the optimum result The research started with the theoretical stud y

about the microwave signal type of antenna and cha racteristi c of the antenna Than

following by patch dime nsion calculation and cell size calculation in the simulation

box before the research invo lves the software simulation where severa l parameter

compri sing the operation freq uency dielectric constant substrate mate rial loss

tangent and etc were preset prior to the design of the antenna Finall y analys is is

make consist of the results from the Smith Chart VSWR Chal1 Return Loss Graph

and Impedance Graph with is generate by the Microwave Office 200 1 simulation

software and come out with the optimum result

II

CHAPTERS

ONE

TWO

TABLE OF CONTENTS

NO CONTENTS

ABSTRACT

ABSTRAK

TABLE OF CONTENTS

LIST OF TABLES

LIST OF FIGURES

11

12

13

INTRODUCTION

Background

Objective

Organization of the project report

2 1

22

LITERATURE REVIEW

Introduction

Basic type of antennas

221 Wire Antennas

222 Aperture Antennas

223 Microstrip antennas

224 Reflector Antennas

225 Len Antennas

III

PAG E

11

III

XI

xii

2

J

4

5

6

6

7

8

23 Definition of important Antennas parameters 9

231 Dielectric Constant 9

232 Bandwidth 10

23J Voltage Standing Wave Ratio (VSWR) II

234 Return Loss 12

235 Efficiency 12

236 Gain3D Pattem 13

237 Polarizati on 13

238 Impedance matching 14

24 Basic Characteristic of Microstri p ante nnas 14

25 Feeding Methods 15

2 6 Methods of Analysis 18

THREE METHODOLGY 19

3 1 Introduction 19

32 Flow chart 20

32 1 Specification of antenna design 2 1

322 Calculation of the patch size 22

323 Cell size calculation 23

324 Feeding in the substrate information 25

325 Patch size drawing 27

326 Simulation and Analysis 28

33 Selection criteria for the optimum antenna design 29

V I

~ - shy---- ---

FOUR

fIVE

41

42

4J

44

45

46

5 1

52

RESULTS AND ANA LYSIS

Si mulation I

Patch size modificat ion

Port Position

Difference feeding Method

Edge modification

Double dielectric substrate

CONCLUSION AND RECOMMENDATION

Conclusion

Recorrune ndations

References

Appendix

30

30

33

36

41

44

45

49

49

50

SI

53

x

- - ---

LIST OF TABLE

Tables Pages

41 Summari es of the results 32

42 Summaries resu lts of expanding patch size horizontall y 34

43 Summaries results of expanding patch size verti call y 34

44 Summaries results of reducing patch size hori zontall y 35

45 Summari es results of reduc ing patch size verticall y 36

46 Summaries results of moving port to left 37

47 Summaries results of moving port to right 38

48 Summaries results of moving port to left down 39

49 Summari es results of movi ng port to right down 39

410 Summari es results of movi ng port to center down 40

411 Summari es results of ex pand the line size 41

412 Summari es results of reduced the line size 42

4 13 Summaries resu lts of extended of line length 43

414 Summ ari es results of reduced of line length 43

415 Summar ies results o f patch sharp mod ification 44

416 Summaries result o f the two layer substrate antenna 46

XI

----- -

LIST OF FIGIlRES

Figures Pages

2 1 Wire antenna configuration S

22 Aperture anteJUla configuration 6

23 Rectangular and circu lar Microstrip antenna 7

24 Typical Reflector configurations 8

2S Basic type of lens configuration 9

26 Microstrip Antennas 14

27 Representative shapes of Microstrip patch elements IS

28 Typical feed s for Microstrip antennas 16

29 Equiva lent ci rcuit for typical feeds 17

3 1 Fl ow chart of the design procedures 20

32 Orientation of the Patch 24

33 Substrate Info nnati on for Enclosure 2shy

34 Substrate In formation for Dielectric Layer 26

3S Substrate Infomlation fo r Boundaries 27

36 Patc h wi th the correct dimen sion 28

41 VSWR chart of simulationl 30

42 Return Loss chart J I

43 Impedance chart 31

44 Expand patch size horizontally 33

4S Expand patch size verti cally 4

xu

~---

46 Reduced patch size horizonta ll y 35

47 Red uced patch size verti cally 36

48 Move port to the left 37

49 Move pOl1 to the rig ht 37

4 10 Move port to the left down 38

4 11 Move port to the right down 39

412 Move port to the center down 40

413 Ex pand the line size 41

414 Reduced the line s ize 42

415 Extend the line length 42

416 Reduced the line length 43

417 Edge modification 44

418 Two layer substrates elect romagnet ically coupled patch 45

419 Return Loss graph (optim um results) 47

420 VSWR (o ptimum resul ts) 47

421 Impedance Graph (optimum results) 48

5 1 Patch dimension (double substrate) 49

X IIl

11

CHAPTER 1

INTRODUCTION

Background

An antennas is defined by Webstars Dictionary as a usual ly metallic device

(as a rod or wire) for radiating or receiving radio waves[2J In the simpl er words is

the region of transi ti on between a guided wave and a free space wave It is a very

impoI1ant part or component in any communicati on system to transmit or receive the

signal to or from the free space And the difference type of system requires

difference type of the antenna

The antenna is a very common device that we can easil y found in this modem

world The television antennas radio antenna hand-phone antenna and many more

electrical and electronic devices are using it Antennas a lso used in many advance

communica tion system li ke radar fo r military propose airpoM surve illance and etc

Microstrip rectangle and square patch antennas have been study and fo und

suitable as single antenna element or for array applicatio n Mierostrip antennas have

several ad vantages compared to conventiona l microwave antennas Because of th is

many ap plications in between the frequency range of IOOMHz to IOOGHz are using

thi s type of antennas

Light weight low volume and thin profile confIguration is the malO

advantages for thi s type of antennas and there are fee l more advantages in state of

the fabrication cost simpler feed ing method easily design and made with dua l

frequency and polarization and required no cavity backing In the same time the

microstrip antennas also have an easier way to integrate with microwave integrated

ci rcuir

In this document experimenta l data is compiled on a difference feeding

method the probe feed and the feed line method The experiment or simulations are

made using Microwave offi ce 2000 CAD

Positioning of the probe feed (By adjustment the probe around some

important position) size and len g1h o f the feed line and shape of the an tennas (made

the cutting on the angle of square patc h antenna) are experimented and compared

The study and experimental also included in doub le or stacked dielectric substrate

Results from all the experiments then are compared and the design with the

best result are taken as the fmal result and used in the real antenna fabrication (this

state is for the future planning)

12 Objectives

The objectives of this project are as follow

I To analyze various type of feeding methods and apply in an an tenna design

II Simulate and design the microstrip antenna or Square patch antenna using

Microwave Office 2000

11 To define the bas ic characteristic and operation of an antenna

I V Simulate and design double or stacked dielectric substrate of the square patch

antenna

2

13 Organization of the project report

This report started with the idea to design a microstrip anterma and organized

in 5 chapters Chapter I describes the basic introduction of the microstrip antermas

application and the imponant of the antenna ad vantages compared with microwave

antennas and described about the objectives of the project

Chapter 2 deal s with the literature review of the project The descriptions

include the bas ic type of an termas some impOJ1ant definition for antennas parameters

like dielectric e lectric constant band width VSWR loss tangent and so for There

also described basic characteristic of the microstrip patch antennas and type of the

feeding methods for the antermas

The procedures to design started from the begirming of the patch dimension

calculation all the parameters apply in the simulation software (Microwave office

2000) and reach the final results which are di scussed in Chapter 3

The analysis is make consist of the results from the experiments the

compan son between various type of experiments and the se lection criteria for the

optimum antermas design are described in Chapter 4

Chapter 5 di scusses the conclusion of the project the fin~i result with is the

best from all the designs and recommendation is made to the project and the further

plarming to improved the project

3

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

ABSTRAK

Kajian ini membincangkan tentang kaedah-kaedah and simulasi untuk merekabentuk

antena jenis square microstrip patch dengan menggunakan peri sian MicroWave Office

2002 Beberapa ujikaji telah dibuat untuk mendapat keputusan yang paling optimum

Kajian ini berm ula dengan pembelajaran ke atas perbagai teori tentang isyarat gelombang

mikro jeni s-jenis antena dan sifat-sifatnya Kemudian diikuti dengan pengiraan untuk

panjang and lebar (dimensi) antena serta sai z untuk sell dalam kotak simulas i peri sian

sebelum bermuJanya simulasi Beberapa parameter yang penting perlu dikcnalpasti

antaranya ialah frequency operasi pemalar dieJektrik bahan dielektrik yang digunakan dan

sebagainya perlu dikenalpasti sebelum proses simulasi dan rekaan dijalankan Akbir sekali

semua keputusan-keputusan hasil daripada peri sian daJ am bentuk carta dan graf dianalisis

Kemudian diakbiri dengan pemilihan keputusan yang paling opti mum

ABSTRACT

This research descri bes the design and simulation of the sq uare Microstrip Patch

antenna usi ng Microwave Office 2002 and addit ional enhancement experimental to

come o ut with the optimum result The research started with the theoretical stud y

about the microwave signal type of antenna and cha racteristi c of the antenna Than

following by patch dime nsion calculation and cell size calculation in the simulation

box before the research invo lves the software simulation where severa l parameter

compri sing the operation freq uency dielectric constant substrate mate rial loss

tangent and etc were preset prior to the design of the antenna Finall y analys is is

make consist of the results from the Smith Chart VSWR Chal1 Return Loss Graph

and Impedance Graph with is generate by the Microwave Office 200 1 simulation

software and come out with the optimum result

II

CHAPTERS

ONE

TWO

TABLE OF CONTENTS

NO CONTENTS

ABSTRACT

ABSTRAK

TABLE OF CONTENTS

LIST OF TABLES

LIST OF FIGURES

11

12

13

INTRODUCTION

Background

Objective

Organization of the project report

2 1

22

LITERATURE REVIEW

Introduction

Basic type of antennas

221 Wire Antennas

222 Aperture Antennas

223 Microstrip antennas

224 Reflector Antennas

225 Len Antennas

III

PAG E

11

III

XI

xii

2

J

4

5

6

6

7

8

23 Definition of important Antennas parameters 9

231 Dielectric Constant 9

232 Bandwidth 10

23J Voltage Standing Wave Ratio (VSWR) II

234 Return Loss 12

235 Efficiency 12

236 Gain3D Pattem 13

237 Polarizati on 13

238 Impedance matching 14

24 Basic Characteristic of Microstri p ante nnas 14

25 Feeding Methods 15

2 6 Methods of Analysis 18

THREE METHODOLGY 19

3 1 Introduction 19

32 Flow chart 20

32 1 Specification of antenna design 2 1

322 Calculation of the patch size 22

323 Cell size calculation 23

324 Feeding in the substrate information 25

325 Patch size drawing 27

326 Simulation and Analysis 28

33 Selection criteria for the optimum antenna design 29

V I

~ - shy---- ---

FOUR

fIVE

41

42

4J

44

45

46

5 1

52

RESULTS AND ANA LYSIS

Si mulation I

Patch size modificat ion

Port Position

Difference feeding Method

Edge modification

Double dielectric substrate

CONCLUSION AND RECOMMENDATION

Conclusion

Recorrune ndations

References

Appendix

30

30

33

36

41

44

45

49

49

50

SI

53

x

- - ---

LIST OF TABLE

Tables Pages

41 Summari es of the results 32

42 Summaries resu lts of expanding patch size horizontall y 34

43 Summaries results of expanding patch size verti call y 34

44 Summaries results of reducing patch size hori zontall y 35

45 Summari es results of reduc ing patch size verticall y 36

46 Summaries results of moving port to left 37

47 Summaries results of moving port to right 38

48 Summaries results of moving port to left down 39

49 Summari es results of movi ng port to right down 39

410 Summari es results of movi ng port to center down 40

411 Summari es results of ex pand the line size 41

412 Summari es results of reduced the line size 42

4 13 Summaries resu lts of extended of line length 43

414 Summ ari es results of reduced of line length 43

415 Summar ies results o f patch sharp mod ification 44

416 Summaries result o f the two layer substrate antenna 46

XI

----- -

LIST OF FIGIlRES

Figures Pages

2 1 Wire antenna configuration S

22 Aperture anteJUla configuration 6

23 Rectangular and circu lar Microstrip antenna 7

24 Typical Reflector configurations 8

2S Basic type of lens configuration 9

26 Microstrip Antennas 14

27 Representative shapes of Microstrip patch elements IS

28 Typical feed s for Microstrip antennas 16

29 Equiva lent ci rcuit for typical feeds 17

3 1 Fl ow chart of the design procedures 20

32 Orientation of the Patch 24

33 Substrate Info nnati on for Enclosure 2shy

34 Substrate In formation for Dielectric Layer 26

3S Substrate Infomlation fo r Boundaries 27

36 Patc h wi th the correct dimen sion 28

41 VSWR chart of simulationl 30

42 Return Loss chart J I

43 Impedance chart 31

44 Expand patch size horizontally 33

4S Expand patch size verti cally 4

xu

~---

46 Reduced patch size horizonta ll y 35

47 Red uced patch size verti cally 36

48 Move port to the left 37

49 Move pOl1 to the rig ht 37

4 10 Move port to the left down 38

4 11 Move port to the right down 39

412 Move port to the center down 40

413 Ex pand the line size 41

414 Reduced the line s ize 42

415 Extend the line length 42

416 Reduced the line length 43

417 Edge modification 44

418 Two layer substrates elect romagnet ically coupled patch 45

419 Return Loss graph (optim um results) 47

420 VSWR (o ptimum resul ts) 47

421 Impedance Graph (optimum results) 48

5 1 Patch dimension (double substrate) 49

X IIl

11

CHAPTER 1

INTRODUCTION

Background

An antennas is defined by Webstars Dictionary as a usual ly metallic device

(as a rod or wire) for radiating or receiving radio waves[2J In the simpl er words is

the region of transi ti on between a guided wave and a free space wave It is a very

impoI1ant part or component in any communicati on system to transmit or receive the

signal to or from the free space And the difference type of system requires

difference type of the antenna

The antenna is a very common device that we can easil y found in this modem

world The television antennas radio antenna hand-phone antenna and many more

electrical and electronic devices are using it Antennas a lso used in many advance

communica tion system li ke radar fo r military propose airpoM surve illance and etc

Microstrip rectangle and square patch antennas have been study and fo und

suitable as single antenna element or for array applicatio n Mierostrip antennas have

several ad vantages compared to conventiona l microwave antennas Because of th is

many ap plications in between the frequency range of IOOMHz to IOOGHz are using

thi s type of antennas

Light weight low volume and thin profile confIguration is the malO

advantages for thi s type of antennas and there are fee l more advantages in state of

the fabrication cost simpler feed ing method easily design and made with dua l

frequency and polarization and required no cavity backing In the same time the

microstrip antennas also have an easier way to integrate with microwave integrated

ci rcuir

In this document experimenta l data is compiled on a difference feeding

method the probe feed and the feed line method The experiment or simulations are

made using Microwave offi ce 2000 CAD

Positioning of the probe feed (By adjustment the probe around some

important position) size and len g1h o f the feed line and shape of the an tennas (made

the cutting on the angle of square patc h antenna) are experimented and compared

The study and experimental also included in doub le or stacked dielectric substrate

Results from all the experiments then are compared and the design with the

best result are taken as the fmal result and used in the real antenna fabrication (this

state is for the future planning)

12 Objectives

The objectives of this project are as follow

I To analyze various type of feeding methods and apply in an an tenna design

II Simulate and design the microstrip antenna or Square patch antenna using

Microwave Office 2000

11 To define the bas ic characteristic and operation of an antenna

I V Simulate and design double or stacked dielectric substrate of the square patch

antenna

2

13 Organization of the project report

This report started with the idea to design a microstrip anterma and organized

in 5 chapters Chapter I describes the basic introduction of the microstrip antermas

application and the imponant of the antenna ad vantages compared with microwave

antennas and described about the objectives of the project

Chapter 2 deal s with the literature review of the project The descriptions

include the bas ic type of an termas some impOJ1ant definition for antennas parameters

like dielectric e lectric constant band width VSWR loss tangent and so for There

also described basic characteristic of the microstrip patch antennas and type of the

feeding methods for the antermas

The procedures to design started from the begirming of the patch dimension

calculation all the parameters apply in the simulation software (Microwave office

2000) and reach the final results which are di scussed in Chapter 3

The analysis is make consist of the results from the experiments the

compan son between various type of experiments and the se lection criteria for the

optimum antermas design are described in Chapter 4

Chapter 5 di scusses the conclusion of the project the fin~i result with is the

best from all the designs and recommendation is made to the project and the further

plarming to improved the project

3

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

ABSTRACT

This research descri bes the design and simulation of the sq uare Microstrip Patch

antenna usi ng Microwave Office 2002 and addit ional enhancement experimental to

come o ut with the optimum result The research started with the theoretical stud y

about the microwave signal type of antenna and cha racteristi c of the antenna Than

following by patch dime nsion calculation and cell size calculation in the simulation

box before the research invo lves the software simulation where severa l parameter

compri sing the operation freq uency dielectric constant substrate mate rial loss

tangent and etc were preset prior to the design of the antenna Finall y analys is is

make consist of the results from the Smith Chart VSWR Chal1 Return Loss Graph

and Impedance Graph with is generate by the Microwave Office 200 1 simulation

software and come out with the optimum result

II

CHAPTERS

ONE

TWO

TABLE OF CONTENTS

NO CONTENTS

ABSTRACT

ABSTRAK

TABLE OF CONTENTS

LIST OF TABLES

LIST OF FIGURES

11

12

13

INTRODUCTION

Background

Objective

Organization of the project report

2 1

22

LITERATURE REVIEW

Introduction

Basic type of antennas

221 Wire Antennas

222 Aperture Antennas

223 Microstrip antennas

224 Reflector Antennas

225 Len Antennas

III

PAG E

11

III

XI

xii

2

J

4

5

6

6

7

8

23 Definition of important Antennas parameters 9

231 Dielectric Constant 9

232 Bandwidth 10

23J Voltage Standing Wave Ratio (VSWR) II

234 Return Loss 12

235 Efficiency 12

236 Gain3D Pattem 13

237 Polarizati on 13

238 Impedance matching 14

24 Basic Characteristic of Microstri p ante nnas 14

25 Feeding Methods 15

2 6 Methods of Analysis 18

THREE METHODOLGY 19

3 1 Introduction 19

32 Flow chart 20

32 1 Specification of antenna design 2 1

322 Calculation of the patch size 22

323 Cell size calculation 23

324 Feeding in the substrate information 25

325 Patch size drawing 27

326 Simulation and Analysis 28

33 Selection criteria for the optimum antenna design 29

V I

~ - shy---- ---

FOUR

fIVE

41

42

4J

44

45

46

5 1

52

RESULTS AND ANA LYSIS

Si mulation I

Patch size modificat ion

Port Position

Difference feeding Method

Edge modification

Double dielectric substrate

CONCLUSION AND RECOMMENDATION

Conclusion

Recorrune ndations

References

Appendix

30

30

33

36

41

44

45

49

49

50

SI

53

x

- - ---

LIST OF TABLE

Tables Pages

41 Summari es of the results 32

42 Summaries resu lts of expanding patch size horizontall y 34

43 Summaries results of expanding patch size verti call y 34

44 Summaries results of reducing patch size hori zontall y 35

45 Summari es results of reduc ing patch size verticall y 36

46 Summaries results of moving port to left 37

47 Summaries results of moving port to right 38

48 Summaries results of moving port to left down 39

49 Summari es results of movi ng port to right down 39

410 Summari es results of movi ng port to center down 40

411 Summari es results of ex pand the line size 41

412 Summari es results of reduced the line size 42

4 13 Summaries resu lts of extended of line length 43

414 Summ ari es results of reduced of line length 43

415 Summar ies results o f patch sharp mod ification 44

416 Summaries result o f the two layer substrate antenna 46

XI

----- -

LIST OF FIGIlRES

Figures Pages

2 1 Wire antenna configuration S

22 Aperture anteJUla configuration 6

23 Rectangular and circu lar Microstrip antenna 7

24 Typical Reflector configurations 8

2S Basic type of lens configuration 9

26 Microstrip Antennas 14

27 Representative shapes of Microstrip patch elements IS

28 Typical feed s for Microstrip antennas 16

29 Equiva lent ci rcuit for typical feeds 17

3 1 Fl ow chart of the design procedures 20

32 Orientation of the Patch 24

33 Substrate Info nnati on for Enclosure 2shy

34 Substrate In formation for Dielectric Layer 26

3S Substrate Infomlation fo r Boundaries 27

36 Patc h wi th the correct dimen sion 28

41 VSWR chart of simulationl 30

42 Return Loss chart J I

43 Impedance chart 31

44 Expand patch size horizontally 33

4S Expand patch size verti cally 4

xu

~---

46 Reduced patch size horizonta ll y 35

47 Red uced patch size verti cally 36

48 Move port to the left 37

49 Move pOl1 to the rig ht 37

4 10 Move port to the left down 38

4 11 Move port to the right down 39

412 Move port to the center down 40

413 Ex pand the line size 41

414 Reduced the line s ize 42

415 Extend the line length 42

416 Reduced the line length 43

417 Edge modification 44

418 Two layer substrates elect romagnet ically coupled patch 45

419 Return Loss graph (optim um results) 47

420 VSWR (o ptimum resul ts) 47

421 Impedance Graph (optimum results) 48

5 1 Patch dimension (double substrate) 49

X IIl

11

CHAPTER 1

INTRODUCTION

Background

An antennas is defined by Webstars Dictionary as a usual ly metallic device

(as a rod or wire) for radiating or receiving radio waves[2J In the simpl er words is

the region of transi ti on between a guided wave and a free space wave It is a very

impoI1ant part or component in any communicati on system to transmit or receive the

signal to or from the free space And the difference type of system requires

difference type of the antenna

The antenna is a very common device that we can easil y found in this modem

world The television antennas radio antenna hand-phone antenna and many more

electrical and electronic devices are using it Antennas a lso used in many advance

communica tion system li ke radar fo r military propose airpoM surve illance and etc

Microstrip rectangle and square patch antennas have been study and fo und

suitable as single antenna element or for array applicatio n Mierostrip antennas have

several ad vantages compared to conventiona l microwave antennas Because of th is

many ap plications in between the frequency range of IOOMHz to IOOGHz are using

thi s type of antennas

Light weight low volume and thin profile confIguration is the malO

advantages for thi s type of antennas and there are fee l more advantages in state of

the fabrication cost simpler feed ing method easily design and made with dua l

frequency and polarization and required no cavity backing In the same time the

microstrip antennas also have an easier way to integrate with microwave integrated

ci rcuir

In this document experimenta l data is compiled on a difference feeding

method the probe feed and the feed line method The experiment or simulations are

made using Microwave offi ce 2000 CAD

Positioning of the probe feed (By adjustment the probe around some

important position) size and len g1h o f the feed line and shape of the an tennas (made

the cutting on the angle of square patc h antenna) are experimented and compared

The study and experimental also included in doub le or stacked dielectric substrate

Results from all the experiments then are compared and the design with the

best result are taken as the fmal result and used in the real antenna fabrication (this

state is for the future planning)

12 Objectives

The objectives of this project are as follow

I To analyze various type of feeding methods and apply in an an tenna design

II Simulate and design the microstrip antenna or Square patch antenna using

Microwave Office 2000

11 To define the bas ic characteristic and operation of an antenna

I V Simulate and design double or stacked dielectric substrate of the square patch

antenna

2

13 Organization of the project report

This report started with the idea to design a microstrip anterma and organized

in 5 chapters Chapter I describes the basic introduction of the microstrip antermas

application and the imponant of the antenna ad vantages compared with microwave

antennas and described about the objectives of the project

Chapter 2 deal s with the literature review of the project The descriptions

include the bas ic type of an termas some impOJ1ant definition for antennas parameters

like dielectric e lectric constant band width VSWR loss tangent and so for There

also described basic characteristic of the microstrip patch antennas and type of the

feeding methods for the antermas

The procedures to design started from the begirming of the patch dimension

calculation all the parameters apply in the simulation software (Microwave office

2000) and reach the final results which are di scussed in Chapter 3

The analysis is make consist of the results from the experiments the

compan son between various type of experiments and the se lection criteria for the

optimum antermas design are described in Chapter 4

Chapter 5 di scusses the conclusion of the project the fin~i result with is the

best from all the designs and recommendation is made to the project and the further

plarming to improved the project

3

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

CHAPTERS

ONE

TWO

TABLE OF CONTENTS

NO CONTENTS

ABSTRACT

ABSTRAK

TABLE OF CONTENTS

LIST OF TABLES

LIST OF FIGURES

11

12

13

INTRODUCTION

Background

Objective

Organization of the project report

2 1

22

LITERATURE REVIEW

Introduction

Basic type of antennas

221 Wire Antennas

222 Aperture Antennas

223 Microstrip antennas

224 Reflector Antennas

225 Len Antennas

III

PAG E

11

III

XI

xii

2

J

4

5

6

6

7

8

23 Definition of important Antennas parameters 9

231 Dielectric Constant 9

232 Bandwidth 10

23J Voltage Standing Wave Ratio (VSWR) II

234 Return Loss 12

235 Efficiency 12

236 Gain3D Pattem 13

237 Polarizati on 13

238 Impedance matching 14

24 Basic Characteristic of Microstri p ante nnas 14

25 Feeding Methods 15

2 6 Methods of Analysis 18

THREE METHODOLGY 19

3 1 Introduction 19

32 Flow chart 20

32 1 Specification of antenna design 2 1

322 Calculation of the patch size 22

323 Cell size calculation 23

324 Feeding in the substrate information 25

325 Patch size drawing 27

326 Simulation and Analysis 28

33 Selection criteria for the optimum antenna design 29

V I

~ - shy---- ---

FOUR

fIVE

41

42

4J

44

45

46

5 1

52

RESULTS AND ANA LYSIS

Si mulation I

Patch size modificat ion

Port Position

Difference feeding Method

Edge modification

Double dielectric substrate

CONCLUSION AND RECOMMENDATION

Conclusion

Recorrune ndations

References

Appendix

30

30

33

36

41

44

45

49

49

50

SI

53

x

- - ---

LIST OF TABLE

Tables Pages

41 Summari es of the results 32

42 Summaries resu lts of expanding patch size horizontall y 34

43 Summaries results of expanding patch size verti call y 34

44 Summaries results of reducing patch size hori zontall y 35

45 Summari es results of reduc ing patch size verticall y 36

46 Summaries results of moving port to left 37

47 Summaries results of moving port to right 38

48 Summaries results of moving port to left down 39

49 Summari es results of movi ng port to right down 39

410 Summari es results of movi ng port to center down 40

411 Summari es results of ex pand the line size 41

412 Summari es results of reduced the line size 42

4 13 Summaries resu lts of extended of line length 43

414 Summ ari es results of reduced of line length 43

415 Summar ies results o f patch sharp mod ification 44

416 Summaries result o f the two layer substrate antenna 46

XI

----- -

LIST OF FIGIlRES

Figures Pages

2 1 Wire antenna configuration S

22 Aperture anteJUla configuration 6

23 Rectangular and circu lar Microstrip antenna 7

24 Typical Reflector configurations 8

2S Basic type of lens configuration 9

26 Microstrip Antennas 14

27 Representative shapes of Microstrip patch elements IS

28 Typical feed s for Microstrip antennas 16

29 Equiva lent ci rcuit for typical feeds 17

3 1 Fl ow chart of the design procedures 20

32 Orientation of the Patch 24

33 Substrate Info nnati on for Enclosure 2shy

34 Substrate In formation for Dielectric Layer 26

3S Substrate Infomlation fo r Boundaries 27

36 Patc h wi th the correct dimen sion 28

41 VSWR chart of simulationl 30

42 Return Loss chart J I

43 Impedance chart 31

44 Expand patch size horizontally 33

4S Expand patch size verti cally 4

xu

~---

46 Reduced patch size horizonta ll y 35

47 Red uced patch size verti cally 36

48 Move port to the left 37

49 Move pOl1 to the rig ht 37

4 10 Move port to the left down 38

4 11 Move port to the right down 39

412 Move port to the center down 40

413 Ex pand the line size 41

414 Reduced the line s ize 42

415 Extend the line length 42

416 Reduced the line length 43

417 Edge modification 44

418 Two layer substrates elect romagnet ically coupled patch 45

419 Return Loss graph (optim um results) 47

420 VSWR (o ptimum resul ts) 47

421 Impedance Graph (optimum results) 48

5 1 Patch dimension (double substrate) 49

X IIl

11

CHAPTER 1

INTRODUCTION

Background

An antennas is defined by Webstars Dictionary as a usual ly metallic device

(as a rod or wire) for radiating or receiving radio waves[2J In the simpl er words is

the region of transi ti on between a guided wave and a free space wave It is a very

impoI1ant part or component in any communicati on system to transmit or receive the

signal to or from the free space And the difference type of system requires

difference type of the antenna

The antenna is a very common device that we can easil y found in this modem

world The television antennas radio antenna hand-phone antenna and many more

electrical and electronic devices are using it Antennas a lso used in many advance

communica tion system li ke radar fo r military propose airpoM surve illance and etc

Microstrip rectangle and square patch antennas have been study and fo und

suitable as single antenna element or for array applicatio n Mierostrip antennas have

several ad vantages compared to conventiona l microwave antennas Because of th is

many ap plications in between the frequency range of IOOMHz to IOOGHz are using

thi s type of antennas

Light weight low volume and thin profile confIguration is the malO

advantages for thi s type of antennas and there are fee l more advantages in state of

the fabrication cost simpler feed ing method easily design and made with dua l

frequency and polarization and required no cavity backing In the same time the

microstrip antennas also have an easier way to integrate with microwave integrated

ci rcuir

In this document experimenta l data is compiled on a difference feeding

method the probe feed and the feed line method The experiment or simulations are

made using Microwave offi ce 2000 CAD

Positioning of the probe feed (By adjustment the probe around some

important position) size and len g1h o f the feed line and shape of the an tennas (made

the cutting on the angle of square patc h antenna) are experimented and compared

The study and experimental also included in doub le or stacked dielectric substrate

Results from all the experiments then are compared and the design with the

best result are taken as the fmal result and used in the real antenna fabrication (this

state is for the future planning)

12 Objectives

The objectives of this project are as follow

I To analyze various type of feeding methods and apply in an an tenna design

II Simulate and design the microstrip antenna or Square patch antenna using

Microwave Office 2000

11 To define the bas ic characteristic and operation of an antenna

I V Simulate and design double or stacked dielectric substrate of the square patch

antenna

2

13 Organization of the project report

This report started with the idea to design a microstrip anterma and organized

in 5 chapters Chapter I describes the basic introduction of the microstrip antermas

application and the imponant of the antenna ad vantages compared with microwave

antennas and described about the objectives of the project

Chapter 2 deal s with the literature review of the project The descriptions

include the bas ic type of an termas some impOJ1ant definition for antennas parameters

like dielectric e lectric constant band width VSWR loss tangent and so for There

also described basic characteristic of the microstrip patch antennas and type of the

feeding methods for the antermas

The procedures to design started from the begirming of the patch dimension

calculation all the parameters apply in the simulation software (Microwave office

2000) and reach the final results which are di scussed in Chapter 3

The analysis is make consist of the results from the experiments the

compan son between various type of experiments and the se lection criteria for the

optimum antermas design are described in Chapter 4

Chapter 5 di scusses the conclusion of the project the fin~i result with is the

best from all the designs and recommendation is made to the project and the further

plarming to improved the project

3

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

23 Definition of important Antennas parameters 9

231 Dielectric Constant 9

232 Bandwidth 10

23J Voltage Standing Wave Ratio (VSWR) II

234 Return Loss 12

235 Efficiency 12

236 Gain3D Pattem 13

237 Polarizati on 13

238 Impedance matching 14

24 Basic Characteristic of Microstri p ante nnas 14

25 Feeding Methods 15

2 6 Methods of Analysis 18

THREE METHODOLGY 19

3 1 Introduction 19

32 Flow chart 20

32 1 Specification of antenna design 2 1

322 Calculation of the patch size 22

323 Cell size calculation 23

324 Feeding in the substrate information 25

325 Patch size drawing 27

326 Simulation and Analysis 28

33 Selection criteria for the optimum antenna design 29

V I

~ - shy---- ---

FOUR

fIVE

41

42

4J

44

45

46

5 1

52

RESULTS AND ANA LYSIS

Si mulation I

Patch size modificat ion

Port Position

Difference feeding Method

Edge modification

Double dielectric substrate

CONCLUSION AND RECOMMENDATION

Conclusion

Recorrune ndations

References

Appendix

30

30

33

36

41

44

45

49

49

50

SI

53

x

- - ---

LIST OF TABLE

Tables Pages

41 Summari es of the results 32

42 Summaries resu lts of expanding patch size horizontall y 34

43 Summaries results of expanding patch size verti call y 34

44 Summaries results of reducing patch size hori zontall y 35

45 Summari es results of reduc ing patch size verticall y 36

46 Summaries results of moving port to left 37

47 Summaries results of moving port to right 38

48 Summaries results of moving port to left down 39

49 Summari es results of movi ng port to right down 39

410 Summari es results of movi ng port to center down 40

411 Summari es results of ex pand the line size 41

412 Summari es results of reduced the line size 42

4 13 Summaries resu lts of extended of line length 43

414 Summ ari es results of reduced of line length 43

415 Summar ies results o f patch sharp mod ification 44

416 Summaries result o f the two layer substrate antenna 46

XI

----- -

LIST OF FIGIlRES

Figures Pages

2 1 Wire antenna configuration S

22 Aperture anteJUla configuration 6

23 Rectangular and circu lar Microstrip antenna 7

24 Typical Reflector configurations 8

2S Basic type of lens configuration 9

26 Microstrip Antennas 14

27 Representative shapes of Microstrip patch elements IS

28 Typical feed s for Microstrip antennas 16

29 Equiva lent ci rcuit for typical feeds 17

3 1 Fl ow chart of the design procedures 20

32 Orientation of the Patch 24

33 Substrate Info nnati on for Enclosure 2shy

34 Substrate In formation for Dielectric Layer 26

3S Substrate Infomlation fo r Boundaries 27

36 Patc h wi th the correct dimen sion 28

41 VSWR chart of simulationl 30

42 Return Loss chart J I

43 Impedance chart 31

44 Expand patch size horizontally 33

4S Expand patch size verti cally 4

xu

~---

46 Reduced patch size horizonta ll y 35

47 Red uced patch size verti cally 36

48 Move port to the left 37

49 Move pOl1 to the rig ht 37

4 10 Move port to the left down 38

4 11 Move port to the right down 39

412 Move port to the center down 40

413 Ex pand the line size 41

414 Reduced the line s ize 42

415 Extend the line length 42

416 Reduced the line length 43

417 Edge modification 44

418 Two layer substrates elect romagnet ically coupled patch 45

419 Return Loss graph (optim um results) 47

420 VSWR (o ptimum resul ts) 47

421 Impedance Graph (optimum results) 48

5 1 Patch dimension (double substrate) 49

X IIl

11

CHAPTER 1

INTRODUCTION

Background

An antennas is defined by Webstars Dictionary as a usual ly metallic device

(as a rod or wire) for radiating or receiving radio waves[2J In the simpl er words is

the region of transi ti on between a guided wave and a free space wave It is a very

impoI1ant part or component in any communicati on system to transmit or receive the

signal to or from the free space And the difference type of system requires

difference type of the antenna

The antenna is a very common device that we can easil y found in this modem

world The television antennas radio antenna hand-phone antenna and many more

electrical and electronic devices are using it Antennas a lso used in many advance

communica tion system li ke radar fo r military propose airpoM surve illance and etc

Microstrip rectangle and square patch antennas have been study and fo und

suitable as single antenna element or for array applicatio n Mierostrip antennas have

several ad vantages compared to conventiona l microwave antennas Because of th is

many ap plications in between the frequency range of IOOMHz to IOOGHz are using

thi s type of antennas

Light weight low volume and thin profile confIguration is the malO

advantages for thi s type of antennas and there are fee l more advantages in state of

the fabrication cost simpler feed ing method easily design and made with dua l

frequency and polarization and required no cavity backing In the same time the

microstrip antennas also have an easier way to integrate with microwave integrated

ci rcuir

In this document experimenta l data is compiled on a difference feeding

method the probe feed and the feed line method The experiment or simulations are

made using Microwave offi ce 2000 CAD

Positioning of the probe feed (By adjustment the probe around some

important position) size and len g1h o f the feed line and shape of the an tennas (made

the cutting on the angle of square patc h antenna) are experimented and compared

The study and experimental also included in doub le or stacked dielectric substrate

Results from all the experiments then are compared and the design with the

best result are taken as the fmal result and used in the real antenna fabrication (this

state is for the future planning)

12 Objectives

The objectives of this project are as follow

I To analyze various type of feeding methods and apply in an an tenna design

II Simulate and design the microstrip antenna or Square patch antenna using

Microwave Office 2000

11 To define the bas ic characteristic and operation of an antenna

I V Simulate and design double or stacked dielectric substrate of the square patch

antenna

2

13 Organization of the project report

This report started with the idea to design a microstrip anterma and organized

in 5 chapters Chapter I describes the basic introduction of the microstrip antermas

application and the imponant of the antenna ad vantages compared with microwave

antennas and described about the objectives of the project

Chapter 2 deal s with the literature review of the project The descriptions

include the bas ic type of an termas some impOJ1ant definition for antennas parameters

like dielectric e lectric constant band width VSWR loss tangent and so for There

also described basic characteristic of the microstrip patch antennas and type of the

feeding methods for the antermas

The procedures to design started from the begirming of the patch dimension

calculation all the parameters apply in the simulation software (Microwave office

2000) and reach the final results which are di scussed in Chapter 3

The analysis is make consist of the results from the experiments the

compan son between various type of experiments and the se lection criteria for the

optimum antermas design are described in Chapter 4

Chapter 5 di scusses the conclusion of the project the fin~i result with is the

best from all the designs and recommendation is made to the project and the further

plarming to improved the project

3

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

FOUR

fIVE

41

42

4J

44

45

46

5 1

52

RESULTS AND ANA LYSIS

Si mulation I

Patch size modificat ion

Port Position

Difference feeding Method

Edge modification

Double dielectric substrate

CONCLUSION AND RECOMMENDATION

Conclusion

Recorrune ndations

References

Appendix

30

30

33

36

41

44

45

49

49

50

SI

53

x

- - ---

LIST OF TABLE

Tables Pages

41 Summari es of the results 32

42 Summaries resu lts of expanding patch size horizontall y 34

43 Summaries results of expanding patch size verti call y 34

44 Summaries results of reducing patch size hori zontall y 35

45 Summari es results of reduc ing patch size verticall y 36

46 Summaries results of moving port to left 37

47 Summaries results of moving port to right 38

48 Summaries results of moving port to left down 39

49 Summari es results of movi ng port to right down 39

410 Summari es results of movi ng port to center down 40

411 Summari es results of ex pand the line size 41

412 Summari es results of reduced the line size 42

4 13 Summaries resu lts of extended of line length 43

414 Summ ari es results of reduced of line length 43

415 Summar ies results o f patch sharp mod ification 44

416 Summaries result o f the two layer substrate antenna 46

XI

----- -

LIST OF FIGIlRES

Figures Pages

2 1 Wire antenna configuration S

22 Aperture anteJUla configuration 6

23 Rectangular and circu lar Microstrip antenna 7

24 Typical Reflector configurations 8

2S Basic type of lens configuration 9

26 Microstrip Antennas 14

27 Representative shapes of Microstrip patch elements IS

28 Typical feed s for Microstrip antennas 16

29 Equiva lent ci rcuit for typical feeds 17

3 1 Fl ow chart of the design procedures 20

32 Orientation of the Patch 24

33 Substrate Info nnati on for Enclosure 2shy

34 Substrate In formation for Dielectric Layer 26

3S Substrate Infomlation fo r Boundaries 27

36 Patc h wi th the correct dimen sion 28

41 VSWR chart of simulationl 30

42 Return Loss chart J I

43 Impedance chart 31

44 Expand patch size horizontally 33

4S Expand patch size verti cally 4

xu

~---

46 Reduced patch size horizonta ll y 35

47 Red uced patch size verti cally 36

48 Move port to the left 37

49 Move pOl1 to the rig ht 37

4 10 Move port to the left down 38

4 11 Move port to the right down 39

412 Move port to the center down 40

413 Ex pand the line size 41

414 Reduced the line s ize 42

415 Extend the line length 42

416 Reduced the line length 43

417 Edge modification 44

418 Two layer substrates elect romagnet ically coupled patch 45

419 Return Loss graph (optim um results) 47

420 VSWR (o ptimum resul ts) 47

421 Impedance Graph (optimum results) 48

5 1 Patch dimension (double substrate) 49

X IIl

11

CHAPTER 1

INTRODUCTION

Background

An antennas is defined by Webstars Dictionary as a usual ly metallic device

(as a rod or wire) for radiating or receiving radio waves[2J In the simpl er words is

the region of transi ti on between a guided wave and a free space wave It is a very

impoI1ant part or component in any communicati on system to transmit or receive the

signal to or from the free space And the difference type of system requires

difference type of the antenna

The antenna is a very common device that we can easil y found in this modem

world The television antennas radio antenna hand-phone antenna and many more

electrical and electronic devices are using it Antennas a lso used in many advance

communica tion system li ke radar fo r military propose airpoM surve illance and etc

Microstrip rectangle and square patch antennas have been study and fo und

suitable as single antenna element or for array applicatio n Mierostrip antennas have

several ad vantages compared to conventiona l microwave antennas Because of th is

many ap plications in between the frequency range of IOOMHz to IOOGHz are using

thi s type of antennas

Light weight low volume and thin profile confIguration is the malO

advantages for thi s type of antennas and there are fee l more advantages in state of

the fabrication cost simpler feed ing method easily design and made with dua l

frequency and polarization and required no cavity backing In the same time the

microstrip antennas also have an easier way to integrate with microwave integrated

ci rcuir

In this document experimenta l data is compiled on a difference feeding

method the probe feed and the feed line method The experiment or simulations are

made using Microwave offi ce 2000 CAD

Positioning of the probe feed (By adjustment the probe around some

important position) size and len g1h o f the feed line and shape of the an tennas (made

the cutting on the angle of square patc h antenna) are experimented and compared

The study and experimental also included in doub le or stacked dielectric substrate

Results from all the experiments then are compared and the design with the

best result are taken as the fmal result and used in the real antenna fabrication (this

state is for the future planning)

12 Objectives

The objectives of this project are as follow

I To analyze various type of feeding methods and apply in an an tenna design

II Simulate and design the microstrip antenna or Square patch antenna using

Microwave Office 2000

11 To define the bas ic characteristic and operation of an antenna

I V Simulate and design double or stacked dielectric substrate of the square patch

antenna

2

13 Organization of the project report

This report started with the idea to design a microstrip anterma and organized

in 5 chapters Chapter I describes the basic introduction of the microstrip antermas

application and the imponant of the antenna ad vantages compared with microwave

antennas and described about the objectives of the project

Chapter 2 deal s with the literature review of the project The descriptions

include the bas ic type of an termas some impOJ1ant definition for antennas parameters

like dielectric e lectric constant band width VSWR loss tangent and so for There

also described basic characteristic of the microstrip patch antennas and type of the

feeding methods for the antermas

The procedures to design started from the begirming of the patch dimension

calculation all the parameters apply in the simulation software (Microwave office

2000) and reach the final results which are di scussed in Chapter 3

The analysis is make consist of the results from the experiments the

compan son between various type of experiments and the se lection criteria for the

optimum antermas design are described in Chapter 4

Chapter 5 di scusses the conclusion of the project the fin~i result with is the

best from all the designs and recommendation is made to the project and the further

plarming to improved the project

3

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

LIST OF TABLE

Tables Pages

41 Summari es of the results 32

42 Summaries resu lts of expanding patch size horizontall y 34

43 Summaries results of expanding patch size verti call y 34

44 Summaries results of reducing patch size hori zontall y 35

45 Summari es results of reduc ing patch size verticall y 36

46 Summaries results of moving port to left 37

47 Summaries results of moving port to right 38

48 Summaries results of moving port to left down 39

49 Summari es results of movi ng port to right down 39

410 Summari es results of movi ng port to center down 40

411 Summari es results of ex pand the line size 41

412 Summari es results of reduced the line size 42

4 13 Summaries resu lts of extended of line length 43

414 Summ ari es results of reduced of line length 43

415 Summar ies results o f patch sharp mod ification 44

416 Summaries result o f the two layer substrate antenna 46

XI

----- -

LIST OF FIGIlRES

Figures Pages

2 1 Wire antenna configuration S

22 Aperture anteJUla configuration 6

23 Rectangular and circu lar Microstrip antenna 7

24 Typical Reflector configurations 8

2S Basic type of lens configuration 9

26 Microstrip Antennas 14

27 Representative shapes of Microstrip patch elements IS

28 Typical feed s for Microstrip antennas 16

29 Equiva lent ci rcuit for typical feeds 17

3 1 Fl ow chart of the design procedures 20

32 Orientation of the Patch 24

33 Substrate Info nnati on for Enclosure 2shy

34 Substrate In formation for Dielectric Layer 26

3S Substrate Infomlation fo r Boundaries 27

36 Patc h wi th the correct dimen sion 28

41 VSWR chart of simulationl 30

42 Return Loss chart J I

43 Impedance chart 31

44 Expand patch size horizontally 33

4S Expand patch size verti cally 4

xu

~---

46 Reduced patch size horizonta ll y 35

47 Red uced patch size verti cally 36

48 Move port to the left 37

49 Move pOl1 to the rig ht 37

4 10 Move port to the left down 38

4 11 Move port to the right down 39

412 Move port to the center down 40

413 Ex pand the line size 41

414 Reduced the line s ize 42

415 Extend the line length 42

416 Reduced the line length 43

417 Edge modification 44

418 Two layer substrates elect romagnet ically coupled patch 45

419 Return Loss graph (optim um results) 47

420 VSWR (o ptimum resul ts) 47

421 Impedance Graph (optimum results) 48

5 1 Patch dimension (double substrate) 49

X IIl

11

CHAPTER 1

INTRODUCTION

Background

An antennas is defined by Webstars Dictionary as a usual ly metallic device

(as a rod or wire) for radiating or receiving radio waves[2J In the simpl er words is

the region of transi ti on between a guided wave and a free space wave It is a very

impoI1ant part or component in any communicati on system to transmit or receive the

signal to or from the free space And the difference type of system requires

difference type of the antenna

The antenna is a very common device that we can easil y found in this modem

world The television antennas radio antenna hand-phone antenna and many more

electrical and electronic devices are using it Antennas a lso used in many advance

communica tion system li ke radar fo r military propose airpoM surve illance and etc

Microstrip rectangle and square patch antennas have been study and fo und

suitable as single antenna element or for array applicatio n Mierostrip antennas have

several ad vantages compared to conventiona l microwave antennas Because of th is

many ap plications in between the frequency range of IOOMHz to IOOGHz are using

thi s type of antennas

Light weight low volume and thin profile confIguration is the malO

advantages for thi s type of antennas and there are fee l more advantages in state of

the fabrication cost simpler feed ing method easily design and made with dua l

frequency and polarization and required no cavity backing In the same time the

microstrip antennas also have an easier way to integrate with microwave integrated

ci rcuir

In this document experimenta l data is compiled on a difference feeding

method the probe feed and the feed line method The experiment or simulations are

made using Microwave offi ce 2000 CAD

Positioning of the probe feed (By adjustment the probe around some

important position) size and len g1h o f the feed line and shape of the an tennas (made

the cutting on the angle of square patc h antenna) are experimented and compared

The study and experimental also included in doub le or stacked dielectric substrate

Results from all the experiments then are compared and the design with the

best result are taken as the fmal result and used in the real antenna fabrication (this

state is for the future planning)

12 Objectives

The objectives of this project are as follow

I To analyze various type of feeding methods and apply in an an tenna design

II Simulate and design the microstrip antenna or Square patch antenna using

Microwave Office 2000

11 To define the bas ic characteristic and operation of an antenna

I V Simulate and design double or stacked dielectric substrate of the square patch

antenna

2

13 Organization of the project report

This report started with the idea to design a microstrip anterma and organized

in 5 chapters Chapter I describes the basic introduction of the microstrip antermas

application and the imponant of the antenna ad vantages compared with microwave

antennas and described about the objectives of the project

Chapter 2 deal s with the literature review of the project The descriptions

include the bas ic type of an termas some impOJ1ant definition for antennas parameters

like dielectric e lectric constant band width VSWR loss tangent and so for There

also described basic characteristic of the microstrip patch antennas and type of the

feeding methods for the antermas

The procedures to design started from the begirming of the patch dimension

calculation all the parameters apply in the simulation software (Microwave office

2000) and reach the final results which are di scussed in Chapter 3

The analysis is make consist of the results from the experiments the

compan son between various type of experiments and the se lection criteria for the

optimum antermas design are described in Chapter 4

Chapter 5 di scusses the conclusion of the project the fin~i result with is the

best from all the designs and recommendation is made to the project and the further

plarming to improved the project

3

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

----- -

LIST OF FIGIlRES

Figures Pages

2 1 Wire antenna configuration S

22 Aperture anteJUla configuration 6

23 Rectangular and circu lar Microstrip antenna 7

24 Typical Reflector configurations 8

2S Basic type of lens configuration 9

26 Microstrip Antennas 14

27 Representative shapes of Microstrip patch elements IS

28 Typical feed s for Microstrip antennas 16

29 Equiva lent ci rcuit for typical feeds 17

3 1 Fl ow chart of the design procedures 20

32 Orientation of the Patch 24

33 Substrate Info nnati on for Enclosure 2shy

34 Substrate In formation for Dielectric Layer 26

3S Substrate Infomlation fo r Boundaries 27

36 Patc h wi th the correct dimen sion 28

41 VSWR chart of simulationl 30

42 Return Loss chart J I

43 Impedance chart 31

44 Expand patch size horizontally 33

4S Expand patch size verti cally 4

xu

~---

46 Reduced patch size horizonta ll y 35

47 Red uced patch size verti cally 36

48 Move port to the left 37

49 Move pOl1 to the rig ht 37

4 10 Move port to the left down 38

4 11 Move port to the right down 39

412 Move port to the center down 40

413 Ex pand the line size 41

414 Reduced the line s ize 42

415 Extend the line length 42

416 Reduced the line length 43

417 Edge modification 44

418 Two layer substrates elect romagnet ically coupled patch 45

419 Return Loss graph (optim um results) 47

420 VSWR (o ptimum resul ts) 47

421 Impedance Graph (optimum results) 48

5 1 Patch dimension (double substrate) 49

X IIl

11

CHAPTER 1

INTRODUCTION

Background

An antennas is defined by Webstars Dictionary as a usual ly metallic device

(as a rod or wire) for radiating or receiving radio waves[2J In the simpl er words is

the region of transi ti on between a guided wave and a free space wave It is a very

impoI1ant part or component in any communicati on system to transmit or receive the

signal to or from the free space And the difference type of system requires

difference type of the antenna

The antenna is a very common device that we can easil y found in this modem

world The television antennas radio antenna hand-phone antenna and many more

electrical and electronic devices are using it Antennas a lso used in many advance

communica tion system li ke radar fo r military propose airpoM surve illance and etc

Microstrip rectangle and square patch antennas have been study and fo und

suitable as single antenna element or for array applicatio n Mierostrip antennas have

several ad vantages compared to conventiona l microwave antennas Because of th is

many ap plications in between the frequency range of IOOMHz to IOOGHz are using

thi s type of antennas

Light weight low volume and thin profile confIguration is the malO

advantages for thi s type of antennas and there are fee l more advantages in state of

the fabrication cost simpler feed ing method easily design and made with dua l

frequency and polarization and required no cavity backing In the same time the

microstrip antennas also have an easier way to integrate with microwave integrated

ci rcuir

In this document experimenta l data is compiled on a difference feeding

method the probe feed and the feed line method The experiment or simulations are

made using Microwave offi ce 2000 CAD

Positioning of the probe feed (By adjustment the probe around some

important position) size and len g1h o f the feed line and shape of the an tennas (made

the cutting on the angle of square patc h antenna) are experimented and compared

The study and experimental also included in doub le or stacked dielectric substrate

Results from all the experiments then are compared and the design with the

best result are taken as the fmal result and used in the real antenna fabrication (this

state is for the future planning)

12 Objectives

The objectives of this project are as follow

I To analyze various type of feeding methods and apply in an an tenna design

II Simulate and design the microstrip antenna or Square patch antenna using

Microwave Office 2000

11 To define the bas ic characteristic and operation of an antenna

I V Simulate and design double or stacked dielectric substrate of the square patch

antenna

2

13 Organization of the project report

This report started with the idea to design a microstrip anterma and organized

in 5 chapters Chapter I describes the basic introduction of the microstrip antermas

application and the imponant of the antenna ad vantages compared with microwave

antennas and described about the objectives of the project

Chapter 2 deal s with the literature review of the project The descriptions

include the bas ic type of an termas some impOJ1ant definition for antennas parameters

like dielectric e lectric constant band width VSWR loss tangent and so for There

also described basic characteristic of the microstrip patch antennas and type of the

feeding methods for the antermas

The procedures to design started from the begirming of the patch dimension

calculation all the parameters apply in the simulation software (Microwave office

2000) and reach the final results which are di scussed in Chapter 3

The analysis is make consist of the results from the experiments the

compan son between various type of experiments and the se lection criteria for the

optimum antermas design are described in Chapter 4

Chapter 5 di scusses the conclusion of the project the fin~i result with is the

best from all the designs and recommendation is made to the project and the further

plarming to improved the project

3

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

46 Reduced patch size horizonta ll y 35

47 Red uced patch size verti cally 36

48 Move port to the left 37

49 Move pOl1 to the rig ht 37

4 10 Move port to the left down 38

4 11 Move port to the right down 39

412 Move port to the center down 40

413 Ex pand the line size 41

414 Reduced the line s ize 42

415 Extend the line length 42

416 Reduced the line length 43

417 Edge modification 44

418 Two layer substrates elect romagnet ically coupled patch 45

419 Return Loss graph (optim um results) 47

420 VSWR (o ptimum resul ts) 47

421 Impedance Graph (optimum results) 48

5 1 Patch dimension (double substrate) 49

X IIl

11

CHAPTER 1

INTRODUCTION

Background

An antennas is defined by Webstars Dictionary as a usual ly metallic device

(as a rod or wire) for radiating or receiving radio waves[2J In the simpl er words is

the region of transi ti on between a guided wave and a free space wave It is a very

impoI1ant part or component in any communicati on system to transmit or receive the

signal to or from the free space And the difference type of system requires

difference type of the antenna

The antenna is a very common device that we can easil y found in this modem

world The television antennas radio antenna hand-phone antenna and many more

electrical and electronic devices are using it Antennas a lso used in many advance

communica tion system li ke radar fo r military propose airpoM surve illance and etc

Microstrip rectangle and square patch antennas have been study and fo und

suitable as single antenna element or for array applicatio n Mierostrip antennas have

several ad vantages compared to conventiona l microwave antennas Because of th is

many ap plications in between the frequency range of IOOMHz to IOOGHz are using

thi s type of antennas

Light weight low volume and thin profile confIguration is the malO

advantages for thi s type of antennas and there are fee l more advantages in state of

the fabrication cost simpler feed ing method easily design and made with dua l

frequency and polarization and required no cavity backing In the same time the

microstrip antennas also have an easier way to integrate with microwave integrated

ci rcuir

In this document experimenta l data is compiled on a difference feeding

method the probe feed and the feed line method The experiment or simulations are

made using Microwave offi ce 2000 CAD

Positioning of the probe feed (By adjustment the probe around some

important position) size and len g1h o f the feed line and shape of the an tennas (made

the cutting on the angle of square patc h antenna) are experimented and compared

The study and experimental also included in doub le or stacked dielectric substrate

Results from all the experiments then are compared and the design with the

best result are taken as the fmal result and used in the real antenna fabrication (this

state is for the future planning)

12 Objectives

The objectives of this project are as follow

I To analyze various type of feeding methods and apply in an an tenna design

II Simulate and design the microstrip antenna or Square patch antenna using

Microwave Office 2000

11 To define the bas ic characteristic and operation of an antenna

I V Simulate and design double or stacked dielectric substrate of the square patch

antenna

2

13 Organization of the project report

This report started with the idea to design a microstrip anterma and organized

in 5 chapters Chapter I describes the basic introduction of the microstrip antermas

application and the imponant of the antenna ad vantages compared with microwave

antennas and described about the objectives of the project

Chapter 2 deal s with the literature review of the project The descriptions

include the bas ic type of an termas some impOJ1ant definition for antennas parameters

like dielectric e lectric constant band width VSWR loss tangent and so for There

also described basic characteristic of the microstrip patch antennas and type of the

feeding methods for the antermas

The procedures to design started from the begirming of the patch dimension

calculation all the parameters apply in the simulation software (Microwave office

2000) and reach the final results which are di scussed in Chapter 3

The analysis is make consist of the results from the experiments the

compan son between various type of experiments and the se lection criteria for the

optimum antermas design are described in Chapter 4

Chapter 5 di scusses the conclusion of the project the fin~i result with is the

best from all the designs and recommendation is made to the project and the further

plarming to improved the project

3

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

11

CHAPTER 1

INTRODUCTION

Background

An antennas is defined by Webstars Dictionary as a usual ly metallic device

(as a rod or wire) for radiating or receiving radio waves[2J In the simpl er words is

the region of transi ti on between a guided wave and a free space wave It is a very

impoI1ant part or component in any communicati on system to transmit or receive the

signal to or from the free space And the difference type of system requires

difference type of the antenna

The antenna is a very common device that we can easil y found in this modem

world The television antennas radio antenna hand-phone antenna and many more

electrical and electronic devices are using it Antennas a lso used in many advance

communica tion system li ke radar fo r military propose airpoM surve illance and etc

Microstrip rectangle and square patch antennas have been study and fo und

suitable as single antenna element or for array applicatio n Mierostrip antennas have

several ad vantages compared to conventiona l microwave antennas Because of th is

many ap plications in between the frequency range of IOOMHz to IOOGHz are using

thi s type of antennas

Light weight low volume and thin profile confIguration is the malO

advantages for thi s type of antennas and there are fee l more advantages in state of

the fabrication cost simpler feed ing method easily design and made with dua l

frequency and polarization and required no cavity backing In the same time the

microstrip antennas also have an easier way to integrate with microwave integrated

ci rcuir

In this document experimenta l data is compiled on a difference feeding

method the probe feed and the feed line method The experiment or simulations are

made using Microwave offi ce 2000 CAD

Positioning of the probe feed (By adjustment the probe around some

important position) size and len g1h o f the feed line and shape of the an tennas (made

the cutting on the angle of square patc h antenna) are experimented and compared

The study and experimental also included in doub le or stacked dielectric substrate

Results from all the experiments then are compared and the design with the

best result are taken as the fmal result and used in the real antenna fabrication (this

state is for the future planning)

12 Objectives

The objectives of this project are as follow

I To analyze various type of feeding methods and apply in an an tenna design

II Simulate and design the microstrip antenna or Square patch antenna using

Microwave Office 2000

11 To define the bas ic characteristic and operation of an antenna

I V Simulate and design double or stacked dielectric substrate of the square patch

antenna

2

13 Organization of the project report

This report started with the idea to design a microstrip anterma and organized

in 5 chapters Chapter I describes the basic introduction of the microstrip antermas

application and the imponant of the antenna ad vantages compared with microwave

antennas and described about the objectives of the project

Chapter 2 deal s with the literature review of the project The descriptions

include the bas ic type of an termas some impOJ1ant definition for antennas parameters

like dielectric e lectric constant band width VSWR loss tangent and so for There

also described basic characteristic of the microstrip patch antennas and type of the

feeding methods for the antermas

The procedures to design started from the begirming of the patch dimension

calculation all the parameters apply in the simulation software (Microwave office

2000) and reach the final results which are di scussed in Chapter 3

The analysis is make consist of the results from the experiments the

compan son between various type of experiments and the se lection criteria for the

optimum antermas design are described in Chapter 4

Chapter 5 di scusses the conclusion of the project the fin~i result with is the

best from all the designs and recommendation is made to the project and the further

plarming to improved the project

3

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

frequency and polarization and required no cavity backing In the same time the

microstrip antennas also have an easier way to integrate with microwave integrated

ci rcuir

In this document experimenta l data is compiled on a difference feeding

method the probe feed and the feed line method The experiment or simulations are

made using Microwave offi ce 2000 CAD

Positioning of the probe feed (By adjustment the probe around some

important position) size and len g1h o f the feed line and shape of the an tennas (made

the cutting on the angle of square patc h antenna) are experimented and compared

The study and experimental also included in doub le or stacked dielectric substrate

Results from all the experiments then are compared and the design with the

best result are taken as the fmal result and used in the real antenna fabrication (this

state is for the future planning)

12 Objectives

The objectives of this project are as follow

I To analyze various type of feeding methods and apply in an an tenna design

II Simulate and design the microstrip antenna or Square patch antenna using

Microwave Office 2000

11 To define the bas ic characteristic and operation of an antenna

I V Simulate and design double or stacked dielectric substrate of the square patch

antenna

2

13 Organization of the project report

This report started with the idea to design a microstrip anterma and organized

in 5 chapters Chapter I describes the basic introduction of the microstrip antermas

application and the imponant of the antenna ad vantages compared with microwave

antennas and described about the objectives of the project

Chapter 2 deal s with the literature review of the project The descriptions

include the bas ic type of an termas some impOJ1ant definition for antennas parameters

like dielectric e lectric constant band width VSWR loss tangent and so for There

also described basic characteristic of the microstrip patch antennas and type of the

feeding methods for the antermas

The procedures to design started from the begirming of the patch dimension

calculation all the parameters apply in the simulation software (Microwave office

2000) and reach the final results which are di scussed in Chapter 3

The analysis is make consist of the results from the experiments the

compan son between various type of experiments and the se lection criteria for the

optimum antermas design are described in Chapter 4

Chapter 5 di scusses the conclusion of the project the fin~i result with is the

best from all the designs and recommendation is made to the project and the further

plarming to improved the project

3

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

13 Organization of the project report

This report started with the idea to design a microstrip anterma and organized

in 5 chapters Chapter I describes the basic introduction of the microstrip antermas

application and the imponant of the antenna ad vantages compared with microwave

antennas and described about the objectives of the project

Chapter 2 deal s with the literature review of the project The descriptions

include the bas ic type of an termas some impOJ1ant definition for antennas parameters

like dielectric e lectric constant band width VSWR loss tangent and so for There

also described basic characteristic of the microstrip patch antennas and type of the

feeding methods for the antermas

The procedures to design started from the begirming of the patch dimension

calculation all the parameters apply in the simulation software (Microwave office

2000) and reach the final results which are di scussed in Chapter 3

The analysis is make consist of the results from the experiments the

compan son between various type of experiments and the se lection criteria for the

optimum antermas design are described in Chapter 4

Chapter 5 di scusses the conclusion of the project the fin~i result with is the

best from all the designs and recommendation is made to the project and the further

plarming to improved the project

3

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

CHAPTER 2

LITERATURE REVIEW

21 Introduction

As we know antennas are fundamental components of all radio systems and

use free space as the carrying medium They are used to interface the transmitter of

receiver to free space

The operation of a simple transmitting antenna can be illustrated by thinking

of an o pen-circuit cable with two conductors At the ope n e nd a phase reversa l

results causing some of the incident voltage to be rad iated away from the

transmission line instead of reflected as is normally the case The radiated energy is

in the form of transverse elect(Omagnetic waves a nd the inc reas ing o r decreasing of

the di stance between the conductors can vary the amount of radiatio n emitted [3]

Bas ically a trans mitting antenna trans mits by exciting it a t the base (or at a

pair of anti nodes) while in a receiving antennas the applied electromagneti c fi eld is

di stributed throughout the entire length of the antenna to receive the s igna l

The magnetic field that the transmitting antenna radiates will produce an

electric current on any metal surface that it strikes Howeve r if the metal that the

signal strikes has a certain length re la ti on to the wavelength the induced CUITent will

be much stronger on the object

4

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

22 Basic type of antennas

As we know difference type of application is the key of c hoos ing the

difference an tennas The consideration is making base on the quality of the incoming

and outgo ing signal So in thi s section we will di scuss briefly some various types of

antennas

221 Wire Antennas

Wire antennas have several of shape such as a stra ight wire (dipole) loop and

he li x as shown in Figure 2 1

Wire antennas are the simplest type of antennas and the advantages of this

type of an tennas are more relate to the shape with are li ghtweight fabricate and easy

to feed

J - 0 1

(a) Dipole (b) Circular (square) loop

(c) Heli x

Figure 2 1 Wire antenna configurations

5

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

222 Aperture Antennas

Aperture antennas are most common type of antennas in microwave

antennas There are many different geometrica l configurations and figure 22 shows

the most popular shape that usury been used The advantages of this type of antennas

are it easy to mount on any surface and their opening can be covered with a dielectri c

material to protect them from envirorunental conditions Usually aperture antennas

are used for space application because of the high-speed applications is c riti ca l [3]

(a) Pyramidal horn

4t~~_ _IJft

L (b) Conical horn

(e) Rectangular waveguide

figure 22 Aperture antenna configurations

223 Microstrip Antennas

Microstrip antennas is another type of antennas with also very popular in

modem communication wo rld This is because of the characteristic of the antennas

with is low profile conformable to any surfaces simple and inexpensive to fabricate

usi ng modem printed circuit technology mechanically robust when mounted on rigid

6

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

surfaces compatible with MMIC designs and very ve rsat ile in tenn s of resonant

frequency Figure 23 shows the rectangular and circuit micros trip (patch) antennas

[2]

PaLch

I lt r

Ground plane

(a) Rectangular Patch antenna

Ground plane

(b) Circular Patch antenna

Figure 23 Rectangular and Circular Microstrip (patch) antenna

224 Reflec tor Antennas

A refl ector antenna is a most powerful in much type o f anlerulas in the

transmitting and receiving signal over the great di stance Thi s type of antenna has

been built with the large diameter up to 306m because it needed to achi eve the high

gain and to transmit and receive signal after millions of miles of travel Figure 24

(a) (b) (c) shown three common configuration of parabolic and comer refl ector

antenna [3]

7

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

Refl ec tor

(a) Parabolic refl ecto r wi th front feed

euro~33 Sub -refl ector

(a) Parabolic reflector with sub-feed

(a) Corner reflector

Figure 24 Typical Reflector configurations

The lens antenna is one type of the antennas with is the ideal of radiate power

delivered to it and form s the transmitter in des ired directions Difference shape of

geometrical configuration and material of the lenses can transform various forms of

divergent energy into plane waves Figure 25 shows some f01111s of the lens antennas

[3]

8

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

Rotational Lens n gt I

=lt~+-----) Rotational Lens n lt 1

Figure 25 Basic type of lens configuration

23 Definition of important Antennas Parameters

In any antennas design some of the important parameters are need to be

cons idered such as die lectric constant bandwidth VSWR return loss efficiency

antennas gain direct ivity polarization and impedance matching

23 1 Dielectric Constant

The dielectric constant is the rel ative permittivity of a material It is

dimensionless and always greater than 1 A dielectric constant nf I is equivalent to

the permittivity of a vacuum which is a fundamental constant (associated with the

speed of light) In other words vacu um has the lowest possible permittiv ity

9

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10

The higher figures a material show for it permittivity the slower the radio

waves will pass and thus making a radio of signal For example a 24 GHz frequency

presents a wavelength shorter than 12cm This means that if a n ante nna is covered

wi th a material with high pennitti vity it will for the same freque ncy find its resonant

point with a shorter (smaller) antenna than would have been the case if it were an

ope n wire This sounds good when you want to build antennas fo r small devices T he

higher the penninivity more the inferior and nalTow-banded the antenna will get

Also a very small antenna has fewer surfaces to absorb the incoming wave

232 Bandwidth

Bandwidth is differing of the higher frequency and the lower freq uency

Nonnally a radio musL need La work on mUltiple frequencies For example the

24GHz ISM band used by Blue-tooth devices has a range from 2400-248J MHz in

this band Blue-Looth communication uses 78 channels for its frequency hopping

technique I MHz between each charmel

This means thaLLhe antenna must perfonn well over a range of frequency So

the goal must be to make it resonant in the middle of that band The term that is

important here is bandwidth or how much band your anLenna works well ove r A

method to judge the efficiently of antenna is using the VSWR measurement

10