Q.Draw the block diagram of a Radar system and explain the function of each block.

A radar system transmits high-power microwave pulses, shares one antenna between transmit and receive using a duplexer, and processes the returned echo to display the target; the block diagram shows each stage and how range is found from the echo delay. …

[!TLDR]

Radar = modulator → transmitter → duplexer → antenna → target → echo → antenna → duplexer → receiver → display; range = (round-trip time x velocity)/2.

A radar system finds the range and direction of a distant target using transmitted and reflected radio waves. Its block diagram and the function of each block are:

1. Modulator: a circuit that performs the (mathematical) multiplication of the carrier and information signals and feeds the resulting signal to the transmitter; it also times the transmitted pulses.
2. Transmitter: produces the high-power RF pulses that are radiated into space through the antenna.
3. Duplexer: switches the single antenna between the transmitter and the receiver alternately, so that the high-power transmitted pulse does not reach and destroy the sensitive receiver, while still allowing the weak echo to pass to the receiver.
4. Radar antenna: transfers the transmitted signal into space with the required distribution and efficiency; the same antenna is used on reception to collect the reflected echo.
5. Receiver: amplifies and demodulates the received RF echo signals and provides video signals at its output.
6. Indicator / Display: presents a continuous graphic picture showing the relative position of the radar targets to the observer.

Range determination: the target range is found from the time difference between the transmitted pulse and the received echo, using

$\text{Range} = \frac{\text{(time lapse)} \times \text{(velocity of EM wave)}}{2}$ …