Radar is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the object(s). Radio waves (pulsed or continuous) from the transmitter reflect off the object and return to the receiver, giving information about the object's location and speed. Radar was developed secretly for military use by several nations in the period before and during World War II. A key development was the cavity magnetron in the UK, which allowed the creation of relatively small systems with sub-meter resolution. The term RADAR was coined in 1940 by the United States Navy as an acronym for RAdio Detection And Ranging[1][2] or RAdio Direction And Ranging.[3][4] The term radar has since entered English and other languages as a common noun, losing all capitalization.

1. MICROWAVE RADAR
SYSTEM
SUBJECT : MICROWAVE ENGINEERING
BY
L.BAALA GAJAKREEDAN

2. RADAR ….
 RADIO DETECTION AND RANGING
 System composed of
Synchronizer
Trans – receiver
Antenna
Duplexer
Target

3. RADAR CLASSIFICATION :
 Primary radar
 Secondary radar
RADAR FREQUENCY BANDS:

4. WHY MICROWAVE ???
 Very compact
 High Gain
Highly directional Antennas
 Radio frequencies
 Suitable for most applications

5. DUPLEXER:
 Coupling
 Isolation
 2 Types:
Using PIN switches
Using Circulators

6. DUPLEXER USING PIN SWITCHES:
DUPLEXER USING CIRCULATOR:

7. RADAR EQUATION:
Where,

8. PULSED RADAR:
 Stationary Target
 RF pulses instead sinusoidal wave
 Range computation:
Maximum Unambiguous Range : Rmax = cTr/2
Minimum Range : Rmin = cƮ/2

9. CW RADAR :
 Moving Target
 Continuous microwaves and frequency modulated CW
 Position + Velocity + Direction
 Doppler Effect :

10. CW DOPPLER RADAR :
 Target move towards radar  f0 increases by fd
 Target move away from radar  f0 decreases by fd
 Low cost radars ( intruder alarms , speed detectors ,
traffic signal control)

11. TRACKING RADAR :
 To keep antenna beam towards the target all the time
 Different beam shapes
 Fan beam
 Height finding equipments

12. APPLICATIONS OF RADAR:
General applications Military and Defence Scientific
1)Navigational aids 1)Searching &aiming 1)Study of planets &
enemy targets &submarines Terrestial space
2)Weather forecast 2) Guidance to missiles 2) Tracking and Guiding
Space probes
3)Tracking Spacecraft 3)Assisting fighter aircrafts