Solution:

The acronym RADAR:

• The RADAR is an acronym derived from Radio Detection and Ranging. Radar is an electromagnetic device for detecting the presence and location of objects.

• The presence of the object, their range and direction are determined by the transmission and return of electromagnetic energy.

• The radar antenna transmits short burst pulses of energy to the target and echoes from this target carry information about the position and quality of the illuminated object.

• The block diagram of an elementary pulsed radar set is given above.

• The transmitter generates a short pulse and sends it to the antenna via duplexer. As soon as a small fraction of the pulse is fed to the duplexer, it disconnects the transmitter from the antenna and connects the receiver to it.

• The transmitted pulse is reflected by the target and a portion of it reachers the antenna. Now the duplexer connects the receiver to the antenna so that the returning echoes can be processed.

• The processed pulses are fed to the necessary display devices which gives the nature and position (range) of the target.

• In most radars, the antenna moves in a predetermined pattern and this process is known as scanning.

• Radar consists of a transmitter and a receiver each connected to a directional antenna through a Duplexer or Transmitter/Receiver switch.

• The transmitter sends out microwave power through the antenna. The receiver collects as much energy as possible from the echoes reflected in its direction by the target.

• In most of the radar systems the receiving antenna is same as the transmitting antenna.