Study & Design of Patch Array AntennaPRESENTED BY :-

M. Junaid Khan (FA12-BET-005)M. Farhan Khan (FA12-BET-049)M. Usman Javaid (SP10-BET-110)

Under the kind guidance of ,Sir. Bilal Tariq Malik

Introduction

Need of Antenna

Progress of Communication system

AIM & OBJECTIVES

To study Micro-strip Patch Antenna.

To design and implement this antenna using the software HFSS, v 13.2 .

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.

Antenna characteristics :-Power gainDirectivityAntenna radiation patternsPolarization

Overview of micro-strip Antenna

Developed after revolution in Electronic Circuit Miniaturization & LSI in 1970.

Used on rockets & missiles previously.

Wireless local area networks (WLAN)

Micro-strip Patch AntennaWhat 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).

Different Parameters of Micro-strip AntennaL = 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.

Basic Principles of OperationThe 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).

Different Shapes of Micro-strip Patch Elements

Advantages of Micro-strip Patch AntennaLight 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.

Disadvantages:-Narrow bandwidthLow efficiencyLow GainExtraneous radiation from feeds and junctionsLow power handling capacity. Surface wave excitation.

The Mathshttp://www.finetune.co.jp/~lyuka/technote/ustrip/

PATCH ANTENNA COVERED BY AIRBOX

Model

Wave Port

DETERMINATION OF CENTER FREQUENCY USING S-PARAMETER:-

Input Impedance

2D Gain

3D Gain

CONCLUSIONThe 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.

REFERENCES:-http://en.wikipedia.org/wiki/Microstrip_antennahttp://www.microwaves101.com/encyclopedia/antenna_ustrip.cfmC. A. Balanis, Antenna Theory, Analysis and Design, JOHN WILEY & SONS,INC, New York 1997.