Comparative study of Micro strip patch antenna and MIMO antennaentesation
Antenna, Working procedure of antenna, Antenna Classification, Technical
issues of Antenna, Smart Antenna, Smart Antenna Classification, Micro strip patch antenna,
Rectangular Micro strip Patch Antenna, Antenna Design, Circular Micro strip patch Antenna,
Comparisons of rectangular and circular Micro strip patch Antenna.
Published on: Mar 4, 2016
Transcripts - Comparative study of Micro strip patch antenna and MIMO antennaentesation
Comparative study of Micro strip patch
antenna and MIMO antenna
Md. Mirazul Haque
What is antenna?
An antenna is a specialize transducer that
converts radio-frequency (RF) fields into
alternating current (AC) or vice-versa.
How does antenna work?
Antenna is one type of transducer that
converts the electrical energy into the electro-
magnetic energy in form of electromagnetic
Antennas are required by any radio receiver or
transmitter to couple its electrical connection
to the electromagnetic field.
1. Aperture Antennas:
a) Horn antenna:
A horn antenna or microwave horn is an
antenna that consists of a flaring metal
waveguides shaped like a horn to direct radio
waves in a beam.
b) Microstrip patch 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
2. Antenna Classification on Polarization Basis:
a) Linearly (Vertically/Horizontally)
If antenna is transmitting/receiving Vertical E
field vector, then antenna is said to be
vertically polarized antenna.
If antenna is transmitting/receiving horizontal
E field vector, then antenna is said to be
horizontally polarized antenna.
b) Circularly Polarized antenna:
If the antenna is able to transmit or receive E field
vectors of any orientation, then antenna is said
to be circularly polarized antenna.
3. Antenna classification on Radiation Pattern Basis:
a) Omnidirectional Antenna
Omnidirectional antennas are those
antennas which will cover equally well in
azimuth direction and having some angle
in elevation direction.
b) Directional antenna:
Antennas which directs its energy in one
particular direction is said to be directional
Smart antenna system:
A smart antenna is a digital wireless communications antenna system that takes advantage
of diversity effect at the source (transmitter), the destination (receiver), or both.
Why smart antenna:
limited allocated spectrum results in a limit on capacity
radio propagation environment and the mobility of users
give rise to signal fading and spreading in time, space and frequency
limited battery life at the mobile device poses power
Smart antenna types:
Switched beam system:
The switched beam system comprises only basic
switching between separate directional antennas.
Switched beam systems can be further divided into
1.single beam directional antenna: In single beam
directional antenna systems, only one beam is active at a
2.multi beam directional antenna: In multiple beam
directional antenna system, antenna can be used and
transmissions are allowed at the same time and frequency.
Fig: switched beam smart antennas
Adaptive beam forming where a Direction of
Arrival (DOA) algorithm is used to determine
the direction of the signal received from the
There are two kinds of adaptive beam
1.Single user beam forming: In single user
beam forming, the antenna beam is adjusted to
track a user and cancel interferers.
2.Multi user beam forming: In multi user beam
forming, there are different beam patterns, and
each beam tracks one user.
Adaptive array system:
Fig: Adaptive array smart antennas
Micro strip patch antenna:
Micro strip or patch antennas
are becoming increasingly
useful because they can be
printed directly onto a circuit
Micro strip antennas are
becoming very widespread
within the mobile phone
market. Patch antennas are
low cost, and are easily
Structure of micro strip patch antenna:
For good antenna performance, a thick dielectric
substrate having a low dielectric constant is desirable
since this provides better efficiency, larger bandwidth and
better radiation .
In general 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 excitation of undesirable modes.
Micro strip antennas are easy to fabricate and
comfortable on curved surface .
The directivity is fairly insensitive to the substrate thickness.
Fig: Structure of micro strip patch antenna
Shapes of Micro strip Patch antenna:
Feeding Techniques of Micro strip patch antenna
1.Microstrip line Feed:
A conducting strip is connected to the
edge of the patch. The feed can be
etched on the substrate.
In this type of feeding the feeding is
done to small another patch instead of
main radiating patch.
3. Coaxial Feeding:
The Coaxial feed or probe feed is a
very common technique used for
feeding Micro strip patch antennas.
Fig:Capacitive feedingFig:Microstrip line feed
What is MIMO?
MIMO (multiple input, multiple output) is an antenna
technology for wireless communications in which
multiple antennas are used at both the source
(transmitter) and the destination (receiver).
A MIMO system has 3 basic features:
Beam-forming (diversity gain),
Diversity (diversity gain),
Spatial multiplexing (increase data rates)
A combination of the 3 features is also possible depending on
the number of TX and Rx elements and number of independent
How MIMO work:
MIMO takes advantage of multi-path.
MIMO uses multiple antennas to send multiple parallel signals (from
In an urban environment, these signals will bounce off trees,
buildings, etc. and continue on their way to their destination (the
receiver) but in different directions.
“Multi-path” occurs when the different signals arrive at the receiver at
the various times.
With MIMO, the receiving end uses an algorithm or special signal
processing to sort out the multiple signals to produce one signal that
has the originally transmitted data.
Multiple data streams transmitted in a single channel at the same
Multiple radios collect multipath signals delivers simultaneous speed,
coverage, and reliability improvement.
Diversity is a reality created by individuals and groups from a broad spectrum of demographic and
Diversity includes, therefore, knowing how to relate to those qualities and conditions that are different
from our own and outside the groups to which we belong, yet are present in other individuals and
Gain is a measure of the ability of a circuit (often an amplifier) to increase the power or amplitude of a
signal from the input to the output by adding energy converted from some power supply to the signal
Beamforming is a type of RF (radio frequency) management in which an access point uses multiple
antennas to send out the same signal.
A radiation pattern defines the variation of the power radiated by an antenna as a function
of the direction away from the antenna.