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GUIDED BY: PREPARED BY:
Prof. J.B.Chaudhri Vijay Yadav (140403111014)
Ravi chaudhri(140403111016)
Sankalchand Patel collage of engineering
Subject : microwave engineering Subjectcode2171001
microwave systems
Content
Wireless communication .
radar systems.
satellite systems
Microwave Antenna
Wireless communication
Wireless communication is the transfer of information or power between two or more
points that are not connected by an electrical conductor.
The most common wireless technologies use radio .
With radio waves distances can be short, such as a few meters for television or as far
as thousands or even millions of kilometers for deep-space radio communications.
It encompasses various types of fixed, mobile, and portable applications, including
two-way radios, cellular telephones, personal digital assistants (PDAs), and wireless
networking.
Other examples of applications of radio wireless technology include
GPS units,
garage door openers.
wireless computer mice.
5
Analog RF systemDigital RF system
Microwave Systems
Microwave communication is line of sight radio
communication For directive antennas, or broadcasting with
omi-directional antennas.
Radio Transmission: the speech signals are converted to EM Power is
transmitted in space towards destination EM waves are intercepted by
receiving antennas and signal power is collected.
Radar Systems.
Radar is an object-detection system that uses radar waves to determine
the range, angle, or velocity of objects. It can be used to detect aircraft,
ships, spacecraft, guided missiles , motor vehicle , weather formations,
and terrain.
A radar system consists of a transmitter producing electromagnetic waves
in the radio or microwaves domain, an emitting antenna, a receiving
antenna (separate or the same as the previous one) to capture any returns
from objects in the path of the emitted signal, a receiver and processor to
determine properties of the object(s).
The modern uses of radar are highly
diverse, including air and terrestrial
traffic control, radar astronomy , air
defense systems , antimissile systems ,
marine radars to locate landmarks and
other ships, aircraft anti-collision
systems, ocean surveillance systems,
outer space surveillance and rendezvous
systems, meteorological precipitation
monitoring.
High tech radar systems are associated
with digital signal processing , machine
learning and are capable of extracting
useful information from very high noise
levels.
applications of microwave radio.
Microwave Antenna
Antennas used can be:
• Omni-directional-in this case radio power is transmitted
Uniformly in all directions
Such type of antenna are preferred where uniform coverage
is desired such as in cellular systems.
• Directional: in case of UHF communication.
• Highly directional: in case of microwave communications,
microwave signals are transmitted in very narrow beam.
Normally 3 M Diameter Antenna at 2 GHz BW has half power
of about 3.4 degrees beam width.
Adaptive Beam Forming
There are two kinds of adaptive antennas: switched beam arrays and
adaptive arrays.
Both switched beam arrays and adaptive arrays are being employed in
some cell phone systems and in newer wireless LANs.
They are particularly beneficial to cell phone systems because they
can boost the system capacity.
• Remote sensing is the science and art of acquiring information about an object, area or phenomena without actually being in contact with it.
• The sensor is usually mounted on moving platforms such as balloons, aircraft and satellites
• Platforms of remote sensing are:
– Land based (surface or ground observation)
– Airborne based (from 100 m to 40 km)
– Space based (from 150 km to 36000 km)
satellite
Two Stations on Earth want to communicate through radio broadcast but are
too far away to use conventional means.
The two stations can use a satellite as a relay station for their communication
One Earth Station sends a transmission to the satellite.
This is called a Uplink.The satellite Transponder converts the signal and
sends it down to the second earth station. This is called a Downlink.
Advantages of Satellites
The advantages of satellite communication over terrestrial communication are:
The coverage area of a satellite greatly exceeds that of a terrestrial system.
Transmission cost of a satellite is independent of the distance from the center of the coverage area.
Satellite to Satellite communication is very precise.
Higher Bandwidths are available for use.
• The disadvantages of satellite communication:
Launching satellites into orbit is costly.
Satellite bandwidth is gradually becoming used up.
There is a larger propagation delay in satellite communication than in
terrestrial communication.
Disadvantages of Satellites
• Satellite Orbits
GEO
LEO
MEO
Molniya Orbit
HAPs
• Frequency Bands
Types of Satellites
Reference
www.google.com
www.wikipedia.com
Reface book
samuel liao- microwave devices and circuit,
THANK YOU