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7/27/2019 Micro Strip Antenna Design
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Study & Design of Micro -
str ip Patch AntennaPRESENTED BY :-
Diptajit Biswas(EC/08/50)
Amit Samanta (EC/08/49)
Saikat Mandal(EC/08/66)
Under the kind guidance of ,
Mr. Asim Biswas
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Introduction
O Need of Antenna
O Progress
of Communication
system
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AIM & OBJECTIVES
O To study Micro-strip Patch Antenna.
O To design and implement this antenna
using the software HFSS, v 11.0 .
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How does an antenna work ?
Antenna is one type oftransducer that converts theelectrical energy into theelectro-magnetic energy in
form of electromagneticwaves.
Antennas are required byany radio receiver ortransmitter to couple itselectrical connection to theelectromagnetic field.
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Antenna characteristics :-Power gain
Directivity
Antenna
radiation patterns
Polarization
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Overview of micro-strip
Antenna
O Developed after revolution in Electronic
Circuit Miniaturization & LSI in 1970.
O Used on rockets & missiles previously.
O Designers choice.
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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 groundplane on the other side.
Invented by Bob Munson
in 1972 (but earlier workby Dechamps goes back
to1953).
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Different Parameters of Micro-
strip AntennaOL = Length of the Micro-strip Patch Element
OW = Width of the Micro-strip Patch Element
Ot= Thickness of Patch
Oh = Height of the DielectricSubstrate.
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Basic Principles of Operation
The patch acts approximatelyas a resonant cavity (shortcircuit walls on top and
bottom, open-circuit walls onthe sides).
In a cavity, only certainmodes are allowed to exist, atdifferent resonant frequencies.
If the antenna is excited at aresonant frequency, a strongfield is set up inside thecavity, and a strong current onthe (bottom) surface of the
patch. This producessignificant radiation (a goodantenna).
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Different Shapes of Micro-strip Patch
Elements
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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.
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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.
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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 popularfeed techniques used are :-
O Micro-strip line.
O Co-axial probe
O Aperture couplingO Proximity coupling
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Software used to design Micro-strip
Patch Antenna
OHFSS is commercial finite element
Omethod solver for electromagnetic
O
Structures.from Anasys Corp.OHFSS stands for High Frequency
OStructural Simulator. It is one of
the
OSeveral commercial tools used for
O
antenna design . It was developedOby Prof. Zontal Cendes and his
Ostudents at Carnegie Mellon Univ.
Oin the year 1989.
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The Design Specifications:-
Dielectric constant(r)=
2.2 r 12.
Frequency (fr) = 1.85 to1.90 GHz
Height (h) = 0.003
oh0.05 o Velocity of light (c) =
310^8 ms-1 .
Practical width (W) = W