DESIGN AND ANALYSIS OF MICROSRTIP
SQUARE PATCH ANTENNA
Under the kind guidance of : PRESENTED BY :-
RAJAT PATHAK (G. L.) (EC 4th Year)
Mr. VIVEK SINGH
Sr. Lecturer SHIVANSHU AWASTHI (EC 4th Year)
EC Department SARVESH KUMAR NISHAD (EC 4th Year)
S.I.E.T., Jhalwa ,Alld
NOVMAN ASIF (EC 4th Year)
TABLE OF CONTENTS
S. 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 OPERATION
8 FEED TECHNIQUES
9 ADVANTAGES OF MICRO-STRIP PATCH ANTENNA
10 DISADVANTAGES OF MICRO-STRIP PATCH ANTENNA
11 APPLICATIONS & REMEDIES
12 SOFTWARE USED
INTRODUCTION
Antennas 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
Dielectric substrate
Antenna Patch
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:
For Calculation of Width :
W = = Where,
C = free space velocity of light
= Dielectric constant of
substrate:
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).
Feed Techniques
Micro-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 :
Micro-strip Line Feed.
A conducting strip is connected to the edge
of 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.
Coaxial Feeding
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.
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 application
Remedies
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 Design
Click 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
To set the model’s units of measurement:
Model:
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.
Adding Patch:
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.
Coax Cable:
The antenna is excited using a coax cable port.
This port is located under the patch
To draw the coax cable port, we start by drawing the infinite ground Cut Out
as shown below
Then 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: Fast
Frequency Setup Type: Linear Count
Start: 1 GHz
Stop: 3 GHz,
Count: 200. Click OK button.
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 probefeedpatch
3. Click the Save button
Analyze:
Model Validation
To validate the model:
1. Select the menu item HFSS > Validation Check
2. Click the Close button
Note: To view any errors or warning messages, use the Message
Manager.
Analyze
To start the solution process:
1. Select the menu item HFSS > Analyze All
The simulation will stop as soon as
the results converge, which is at pass
10
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.
Advantages
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.
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.
