DESIGN AND ANALYSIS OF MICROSRTIP SQUARE PATCH ANTENNA

Under the kind guidance of :

Mr. VIVEK SINGH Sr. LecturerEC DepartmentS.I.E.T., Jhalwa ,Alld

PRESENTED BY :-

RAJAT PATHAK (G. L.) (EC 4th Year)

SHIVANSHU AWASTHI (EC 4th Year)

SARVESH KUMAR NISHAD (EC 4th Year)

NOVMAN ASIF (EC 4th Year)

TABLE OF CONTENTSS. NO. TOPICS

1 INTRODUCTION

2 HOW DOES AN ANTENNA WORK

3 MICRO-STRIP PATCH ANTENNA

4 DIFFERENT SHAPES OF MICRO-STRIP PATCH ANTENNA

5 DIFFERENT PARAMETERS OF MICRO-STRIP PATCH ANTENNA

6 CALCULATION OF PARAMETERS

7 BASIC PRINCIPLE OF OPERATION8 FEED TECHNIQUES9 ADVANTAGES OF MICRO-STRIP PATCH ANTENNA

10 DISADVANTAGES OF MICRO-STRIP PATCH ANTENNA11 APPLICATIONS & REMEDIES

12 SOFTWARE USED

INTRODUCTIONAntennas are key components of any wireless system.

An antenna is a device that transmits and/or receives electromagnetic waves.

Most antennas are resonant devices, which operate efficiently over a

relatively narrow frequency band.

An antenna must be tuned to the same frequency band that the radio system to

which it is connected operates in, otherwise reception and/or transmission will

be impaired.

How does an antenna work ? Antenna is one type of transducer that

converts the electrical energy into the electro-magnetic energy in form of electromagnetic waves.

Antennas are required by any radio receiver or transmitter to couple its electrical connection to the electromagnetic field.

Microstrip Antenna

Antenna Patch

Dielectric substrate

Ground plane What is Micro-strip Antenna ? In its most basic form, a Microstrip patch antenna consists of a radiating patch on one side of a dielectric substrate which has a ground plane on the other side.Invented by Bob Munson in 1972 (but earlier work by Dechamps goes back to1953).

Different Shapes of Micro-strip Patch Elements

Different Parameters of Microstrip Antenna

L = Length of the Micro-strip Patch Element

W = Width of the Micro-strip Patch Element

t= Thickness of Patch

h = Height of the Dielectric Substrate.

CALCULATION OF PARAMETERS The methodology used is based on the design specs of a particular rectangular microstrip patch antenna:

Where,C = free space velocity of light = Dielectric constant of substrate

For Calculation of Width:W = =

For Calculation effective dielectric constant:

= Where, h = thickness of antenna

For Calculation of Actual Length:

L =

Basic Principles of Operation The patch acts approximately as

a resonant cavity (short circuit walls on top and bottom, open-circuit walls on the sides).

In a cavity, only certain modes are allowed to exist, at different resonant frequencies.

If the antenna is excited at a resonant frequency, a strong field is set up inside the cavity, and a strong current on the (bottom) surface of the patch. This produces significant radiation (a good antenna).

Micro-strip Line Feed.A conducting strip is connected to the edgeof the patch. The feed can be etched on the substrate.Capacitive Feeding

In this type of feeding the feeding is done to small another patch instead of main radiating patch.

Feed TechniquesMicro-strip antenna can be feed by variety of methods. This methods can be classified into two categories-contacting and non-contacting. The foremost popular feed techniques used are :

The Coaxial feed or probe feed is a very common technique used for feeding Microstrip patch antennas.

The center conductor of the coaxial connecter is soldered to the patch.

Coaxial Feeding

Advantages of Micro-strip Patch Antenna

Light weight and low volume. Low profile planar configuration which can be easily made

conformal to host surface. Low fabrication cost, hence can be manufactured in large

quantities. Supports both, linear as well as circular polarization. Can be easily integrated with microwave integrated circuits

(MICs). Capable of dual and triple frequency operations. Mechanically robust when mounted on rigid surfaces. Useful in aircraft, satellites and missile applications

Disadvantages

Narrow bandwidth Low efficiency Low Gain Extraneous radiation from feeds and junctions Poor end fire radiator except tapered slot antennas Low power handling capacity. Surface wave excitation.

Applications Used in mobile satellite communication system. Used in aircraft , spacecraft & missiles Direct broad cast television(DBS). GPS system. Telemetry & telemedicine Radar applicationRemedies

Low power and low gain can overcome by arrays configuration.

Surface wave associated limitations such as poor efficiency, increased mutual coupling, reduced gain and radiation pattern can overcome.

The band width can increase up to 60% by using some special techniques.

Software Used To Design Micro-strip Patch Antenna

HFSS is commercial finite element method solver for electromagnetic structures from Ansys Corp.

HFSS stands for High Frequency Structural Simulator.

It is one of the several commercial tools used for antenna design .

It was developed by Prof. Zontal Cendes and his students at Carnegie Mellon Univ. in the year 1989.

Its gold-standard accuracy, advanced solver and compute technology have made it an essential tool for engineers designing high-frequency and high-speed electronics components.

Getting Started With HFSS

Create the New Project:Click File>New. A new project is listed in the project tree in the Project Manager window.

Inserting an HFSS DesignClick Project>Insert HFSS Design or Insert HFSS-IE Design. The new design is listed in the project tree. It is named HFSS Design .The 3D Modeler window appears to the right of the Project Manager.

Selecting the Solution Type:Click HFSS>Solution Type. The Solution Type

dialog box appears.

Select one of the following solution types

1.Driven Mode (preff.)

2.Driven Terminal

3.Eigenmode

Setting Units of Measurement for the

Model: To set the model’s units of measurement:

Click Modeler>Units. The Set Model Units dialog box

appears.

Select the new units for the model from the Select units

pull-down list.

Assigning Materials: You can add, remove, and edit materials in two main ways:

•Using the Tools>Edit Configured Libraries>Materials menu command.

• Right-clicking Materials in the project tree and selecting Edit All Libraries.

To assign a material to an object, follow

this general procedure:1.Select the object to which you want to assign a material.

2.Click Modeler>Assign Material

Assigning HFSS-IE Boundaries:

Creating Microstrip Patch Antenna:Adding Ground (GND) : To draw the GND, click on the toolbar. Then draw a box by filling the following data as shown below.Make sure to set the transparency greater or equal to 0.6

Creating Microstrip Patch Antenna:Adding Substrate : To draw the Substrate, click on the toolbar. Then draw a box by filling the following data as shown below.

2 - To draw the Patch, click on the toolbar. Then draw rectangle by filling the data same as like filled in substrate .3 – Then the Ground is prepared as like of patch taking its suitable value.

Adding Patch:

Coax Cable:

The antenna is excited using a coax cable port. This port is located under the patchTo draw the coax cable port, we start by drawing the infinite ground Cut Out

as shown belowThen select the Ground & Cut Out, right click, select Edit > Boolean > Subtract

Create the coax:

So to create the coax, select the menu item Draw > Cylinder, then enter the data

Create the Coax Pin: Select the menu item Draw > Cylinder, then enter the data

Assigning Waveport:

•Create the Wave port to create a circle that represents the port •Select the menu item Draw > Circle,•To assign wave port excitation, select Port 1, then go to menu item HFSS > Excitations > Assign > Wave port

Create the Probe:To create the probe, select the menu item Draw > Cylinder, then enter the data

To draw the Air Box, click on the toolbar. Then draw a box by filling the following data .

Now select Box 1, right click > Assign

Boundary > Radiation

Analysis Setup:

Select the menu item HFSS > Analysis Setup > Add Solution Setup.

In the Solution Setup window, click the general tab, Solution frequency is

2.55 GHz, Maximum Number of Passes is 20.

Adding Frequency Sweep: To add a frequency sweep, select the menu item HFSS > Analysis Setup > Add Sweep.

Select Solution Setup Setup1. Click OK button. Then Edit Sweep Window. Sweep Type: FastFrequency Setup Type: Linear CountStart: 1 GHz Stop: 3 GHz,Count: 200. Click OK button.

The simulation will stop as soon as the results converge, which is at pass 10

Save Project:To save the project:1. In an Ansoft HFSS window, select the menu item File > Save As.2. From the Save As window, type the Filename: hfss probefeedpatch3. Click the Save buttonAnalyze:Model ValidationTo validate the model:1. Select the menu item HFSS > Validation Check2. Click the Close buttonNote: To view any errors or warning messages, use the MessageManager.AnalyzeTo start the solution process:1. Select the menu item HFSS > Analyze All

Create Reports:

To create a report, select Results > Create Report.

Set Report Type to Modal S Parameters,

Display Type to Rectangular then click OK

button

Note that you can create any type of report it all depends on what you want

to analyze specifically.

1. HFSS is an interactive simulation system whose basic mesh element is a

tetrahedron. This allows you to solve any arbitrary 3D geometry, especially

those with complex curves and shapes, in a fraction of the time it would

take using other techniques.

2. Ansoft pioneered the use of the Finite Element Method (FEM) for EM

simulation by developing / implementing technologies such as tangential

vector finite elements, adaptive meshing. .

3. HFSS has evolved over a period of years with input from many users and

industries. In industry, Ansoft HFSS is the tool of choice for High

productivity research, development, and virtual prototyping.

Advantages

Conclusion The simulation of microstrip patch antenna is carried out.

The various methodology necessary for simulation are done.

The substrate and patches are created.

The radiation pattern are observed. Rectangular patch antenna at 2.55 GHz

is designed on Ansoft HFSS.

The designed antenna is suitable for Mobile Communication, Cell Phone

Antennas etc.

The simulation gave results good enough to satisfy our requirements to

fabricate it on hardware which can be used wherever needed.