Design and analysis of various types of Micro Strip Antennas Under esteemed guidence

of Mr.J.Lakshmi Narayana M.Tech,Ph.D

D.L.Pavan kumar

J.Anusha

B.Manikanta

K.Vidya rani

M.Sampath kumar

Introduction to Micro Strip Antennas In genaral Micro strip antennas are also known as

“ PRINTED ANTENNAS ”.These are mostly used at microwave

frequencies Because the size of the antenna is directly

tied the wavelength at the resonant frequency.Micro strip patch antenna or patch antenna is

a narrowband wide-beam antenna.The patch usually fed along the centerline

to symmetry and thus minimize exitation of

undesirable modes.

Micro strip antennas are easy to fabricate and comfortable on curved surface .

The directivity is fairly insensitive to the substrate thickness.

Micro strip patch antennas

patches are in variety of shapes ,

such as rectangular , square ,

triangular and circulator

Aim: The design and analysis of various micro strip patch

antennas such as rectangular ,square ,circular and arrays are proposed in this project .

An artificial neural network model are to be developed for proposed micro strip antennas .

A comparative study on the performance of various micro strip antennas i.e between square , circular,rectangular antennas are observed.

Patch Shapes Are:

Other Shapes Are :

Substrates are:The most commonly used substrates are, 1) Honey comb(dielectric

constant=1.07) 2)Duroid(dielectric constant=2.32) 3)Quartz(dielectric constant=3.8) 4)Alumina(dielectric constant=10) A thicker substrate will increase the

radiation power , reduce conductor loss and improve Band width.

Feeding Techniques:Coaxial feedMicrostrip feedProximity coupled microstrip feedAperture coupled microstrip feedCoplanar wave guide

Among all the feeds most prefarable one is coaxial feed.Because impedence matching is achived through this feed .This feed is using huygen’s principle modeled by cylindrical band of electric current.

Comparision of various types of flat profile printed antennas:Charaterstics Microstrip

patch antennaMicrostrip slot antenna

Printed diploe antenna

Profile Thin Thin Thin

Fabrication Very easy Easy Easy

Polarization Both linear& circular

Both linear& circular

Linear

Dual freq operation

Possible Possible Possible

Shape Any shape Rec &circle Rec &tiangular

Spurious radiation

Exists Exists exists

Softwares used:For design and simulation we are using ‘MAT

LAB’ softwareFor analysis we are using the ‘SONET’ and

‘AN-SOFTWARE.For artificial neural networks model we are

using the different simulation softwares.

Advantages:Easy to fabricate on curved surfacesEasily integratedDual frequency and dual polarization can be

easily made.Linear and circular polarization is possibleLow cost , Less sizeCan be integrated in microwave circuits

Disadvantages:Narrow bandwidth associated with

Tollerence problemLower gain(nearly 6db)Large ohmic losses in feed structure of arraysExitation of surface wavesMost microstrip antetnnas radiate into half-

space

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 upto 60% by using some special techniques.

Applications:Used in mobile satellite communication

system.Direct broad cast telivision(DBS).Wire less LAN’S.Feed elements in coaxial system GPS system.Missiles and telementry

Microstrip antenna used in robot:

References:Microstrip antenna design hand book Author: BAHL and BHARTIAAnalysis and design of microstrip antennas Author :Alka Verma Microwave journal Author:Pasquale Dottorato