1. Study & Design of Micro-strip Patch Antenna
PRESENTED BY :- Diptajit Biswas(EC/08/50) Amit Samanta (EC/08/49) Saikat Mandal(EC/08/66) Under the kind guidance of , Mr. Asim Biswas

2. Introduction
Need of Antenna
Progress
of Communication
system

3. AIM & OBJECTIVES To study Micro-strip Patch Antenna.
To design and implement this antenna using the software HFSS, v

4. 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.

5. Antenna characteristics :-
Power gain
Directivity
Antenna
radiation patterns
Polarization

6. Overview of micro-strip Antenna
Developed after revolution in Electronic Circuit Miniaturization & LSI in 1970.
Used on rockets & missiles previously.
Designer’s choice.

7. Micro-strip Patch Antenna
What is Micro-strip Antenna ?
A Micro-strip 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).

8. Different Parameters of Micro-strip 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.

9. 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).

10. Different Shapes of Micro-strip Patch Elements

11. 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.

12. 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.

13. Feed Techniques:- Micro-strip line. Co-axial probe Aperture coupling
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.
Co-axial probe
Aperture coupling
Proximity coupling

14. Software used to design Micro-strip Patch Antenna
HFSS is commercial finite element
method solver for electromagnetic
Structures.from Anasys 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.

15. The Design Specifications:-
Dielectric constant(εr)=
2.2 ≤ εr≤ 12.
Frequency (fr) = 1.85 to 1.90 GHz
Height (h) = λo≤h≤0.05 λo
Velocity of light (c) =
3×10^8 ms-1 .
Practical width (W) = W< λo , , where λo is the free-space wavelength
Practical Length (L) =
0.3333λo< L < 0.5 λo

16. Calculation of Parameters:-
c= 3.8 x 10^8 m/sec
εr =11.9
fo= 1.85 GHz
Therefore,
W=31.9 mm

17. εr =11.9
h = 1.59 mm
W= 31.9 mm
Therefore ,
is euqal to

18. εr =11.9
h=1.59 mm
W = 31.9 mm
Therefore ,
The value of is 6.72x10-1 mm

19. fo= 1.85 GHz =
c= 3x108 m/sec
therefore , the value of is 24.7 mm & value of L will be mm.

20. PATCH ANTENNA COVERED BY AIRBOX

21. WAVE PORT

22. DETERMINATION OF CENTER FREQUENCY USING S-PARAMETER:-

23. VSWR PLOT OF MICROSTRIP ANTENNA

24. PERFECT E ASSIGNED TO SUBSTRATE

25. PERFECT E ASSIGNED TO PATCH

26. APPLICATIONS
The use of micro-strip antennas for integrated phased array systems.
Used in GPS (Sat. Navigational System) technology.
Mobile satellite communications, the Direct Broadcast Satellite (DBS) system & remote sensing.
Non-satellite based applications- such as medical hyperthermia.

27. CONCLUSION
The design of patch antenna using ANSOFT HFSS Software has been shown here. Our project on Design of Microstrip Antenna which is based on Microstrip Feed Line Technique.
Many more design options and impletation techniques are available.

28. REFERENCES:- http://en.wikipedia.org/wiki/Microstrip_antenna
C. A. Balanis, “ Antenna Theory, Analysis and Design”, JOHN WILEY & SONS,INC, New York 1997.