Basic design of a radar system

Reference:  http://www.radartutorial.eu/01.basics/Radar%20Principle.en.html

RADAR： RAdio Detection And Ranging

- All targets produce a diffuse reflection i.e. it is reflected in a wide number of directions. The reflected signal is also called scattering. Backscatter is the term given to reflections in the opposite direction to the incident rays

Transmitter 

The radar transmitter produces the short duration high-power rf pulses of energy that are into space by the antenna.

Duplexer 

The duplexer alternately switches the antenna between the transmitter and receiver so that only one antenna need be used. This switching is necessary because the high-power pulses of the transmitter would destroy the receiver if energy were allowed to enter the receiver.

Receiver

The receivers amplify and demodulate the received RF-signals. The receiver provides video signals on the output.

Radar Antenna

The Antenna transfers the transmitter energy to signals in space with the required distribution and efficiency. This process is applied in an identical way on reception.

Indicator

The indicator should present to the observer a continuous, easily understandable, graphic picture of the relative position of radar targets.

The radar screen (in this case a PPI-scope) displays the produced from the echo signals bright blibs. The longer the pulses were delayed by the runtime, the further away from the center of this radar scope they are displayed. The direction of the deflection on this screen is that in which the antenna is currently pointing.