Microstrip Antenna ppt

8/17/2019 Microstrip Antenna ppt

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DESIGN OPTIMIZATION OF

MICROSTRIP FED

RECTANGULAR MICROSTRIP

ANTENNA USING

DIFFERENTIAL EVOLUTION

ALGORITHM

By

Malay Gangopadhyay, Bhaskar Gupta,

Pinaki Mukherjee, Suvrajit Manna andUdit Sharma


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INTRODUCTION

Motivation for the

work

The motivation behind thiswork is to design a simple

structure of a microstrip

antenna using inset feed

mechanism which radiates

exactly at the target frequency

of designed antenna

parameters with best possible

impedance matching,

significant gain and good

radiation efficiency.


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OBJECTIVE

Objective – The objective of the work isto optimize the dimensions of amicrostrip inset fed patch antenna for

desired resonant frequenc and return!oss"

Method adopted – Di#erentia! evo!utiona!$orithm"


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%I&TOR'

(irst deve!oped b Deschamps in )*+,-ear!iest known rea!ization of .icrostripstructure"

(irst patent obtained b /utton and0ussinot in )*++"

1ractica!! deve!oped b .unson and

%owe!! in the )*23s"


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.icrostrip 1atch 4ntenna

Narrowband5 !ow pro6!e antenna

&ma!! and conforma! in size It consists of a conductin$ patch

on one side of a die!ectricsubstrate with a $round p!ane onthe other side"


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4118IC4TION& O( .&4

&ate!!ite communications5 directbroadcast services 9D0&:

&ate!!ite navi$ation receivers .obi!e radio9pa$ers5 te!ephone: /!oba! 1ositionin$ &stem 9/1&: 0!uetooth automotive app!ications with

R%C1 &ate!!ite Di$ita! 4udio Radio &ervices

9&D4R&:

4nd man more;


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4D


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DI&4D


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8IN= (==D .=C%4NI&.& (OR .&4

Microstrip line feed

Advantages> Impedance matchin$ and fabrication become easier" .ono!ithic"Disadvantages> spurious radiation"

Microstrip line


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Dierent !volutionary Algorithm

Introduced b &torn and 1rice in )**?" &tochastic popu!ation based optimization

a!$orithm, deve!oped to optimize rea! parametersand rea! va!ued functions"

/4 on crossover5 whereas5 D= on mutation It aims at evo!vin$ a popu!ation of M-dimensiona!

parameter vectors5 so-ca!!ed individua!s5 towardsachievin$ the $!oba! optimum" M stands for the

number of parameters"


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Dierential !volution"D!#$ Main ingredients of Dierential !volution "D!#$

%nitialisation $ M-dimensiona! parameter vectorsare initia!ised as a popu!ation for each $eneration G"

&i'G'()'**'+P where NP isindividua! number in a $roup" Mutation $ 4 mutant vector v i,G is $enerated for

each individua! accordin$ to the fo!!owin$ formu!a>vi,G(&p),G-"&p.,G / &p0,G#

where ( is a rea! and constantfactor satis6ed ( @ A35 B1


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Dierential !volution"D!#$ Crossover $ Crossover is app!ied to $enerate a tria!

individua! u ji,G u ji,G ( v ji,G' if 9r9j: CR:&ji,G

otherwisewhere r 9 j: is a rea! random number and CR, aconstant in A35 )5 is the crossover probabi!it"

Selection $ The cost va!ue of each tria! vectoruiG is compared to the cost va!ue of the tar$et

vector Ei,G in the current popu!ation and the one withbetter cost va!ue is retained for the neEt $eneration"


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Optimization of .icrostrip (ed 4ntenna

Analysis 2ased on 3ransmission 4ineModel The =quations used for Optimization are>

The resonant frequenc of a rectan$u!ar microstrip patchantenna is $iven b>

f rFcGB8e# Hre#" Jhere 8e# is the e#ective !en$th of the patch antenna 9due tofrin$in$ e#ect : $iven b

8e# F8KBL8L8F3"M)BhA9eK3",:9JGhK3"B?M:GA9e-3"B+:9JGhK3":

re# is the e#ective permittivit of the antenna substrate $iven beF9rK):GBKA9r-):GB9)K)BhGJ:-)GB


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The return !oss 8R of the microstrip patch is $iven b

8R F B3 8o$ 9)Grf : 5

where rf is the rePection co-eQcient $iven b

rf F9 R

in -+3:G9R

inK +3:"

(rom the transmission !ine mode! it can be shown thatthe input resistance of a patch antenna at resonantfrequenc is $iven b>

RinF)GB/)cosBA98):

where /) is the se!f conductance of radiatin$ s!ots of thepatch"

F SG98:and 8) F inset feed !en$th


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1arameters chosen for optimization are> 8en$th5 Jidth andthe (eed 1osition of the antenna"

Optimization is done usin$ Di#erentia! =vo!ution 4!$orithm" The 6tness function used is>

( F f 3 (3 K 8R 83 Jhere5 f 3 -the tar$et resonant frequenc

(3 - the resonant frequenc with optimized dimensions

8R -is the desired return !oss which is taken here as -,3d0

83 -is the return !oss with optimized dimensions"


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1opu!ation size>B3 Crossover constant> 3"? Di#erentia! mutation constant9(:>3"M Tota! number of $enerations >B33


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R=&U8T&

Optimum patch !en$th5 width V feed position9inset: and

return !oss for di#erent va!ues of resonant frequenc


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R=&U8T&

0est 6tness p!ot for D= optimization


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R=&U8T&

&imu!ated return !oss for a tpica! antenna optimized usin$ D=for resonant frequenc )) /%z"


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R=&U8T&

1!ot of tota! 6e!d $ain vs" frequenc for a tpica! antennaoptimizedusin$ D= for resonant frequenc )) /%z".aE $ain- +"* d0i at )) /%z


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R=&U8T&

Radiation patterns of a tpica! antenna optimized usin$ D= for resonant

frequenc )) /%z


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R=(=R=NC=&

)" &torn5 R"W 1rice5 X" 9)**2:" YDi#erentia! =vo!ution- a simp!e and eQcientheuristic for $!oba! optimization over continuous spacesY" Journal of GlobalOptimization ))> ,M),+*" doi>)3")3B,G4>)33B3BB),B"B" 1rice5 X"W &torn5 R"."W 8ampinen5 Z"4" 9B33+:" Dierential !volution" #Practical #pproach to Global Optimization" &prin$er"," 4" Deb5 Z"&" Ro5 0" /upta5 [Desi$n of .icrostrip antennas usin$ Di#erentia!=vo!ution a!$orithm\5 $nternational Journal of $nformation %&'tem' andCommunication, vo!" )5pp )-)M5B3))M" =" 4kso and =" 4facan5 [1!anar antenna pattern nu!!in$ usin$ di#erentia!evo!ution a!$orithm\5 4=U -$nternational Journal of !lectronic' andCommunication'5


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R=(=R=NC=&

2" 8" ]han$5 ]" Cui5 '" C" Ziao5 (-&" ]han$5 [0roadband patch antennadesi$n usin$ di#erentia! evo!ution a!$orithm\5 Micro+ave - Optical.echnolo(& /etter',


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Microstrip Antenna ppt