Topic: Radar Systems
Which of the following statement is not true about delay line cancellers?
- A. It eliminates DC components of fixed targets and passes AC components of moving targets
- B. It is used in moving target indicator radar
- C. Time delay in one channel of the delay line canceller is one half of the pulse repetition period
- D. It rejects any moving target whose Doppler frequency happens to be the same as the PRF or a multiple thereof
Answer: C. Time delay in one channel of the delay line canceller is one half of the pulse repetition period
Explanation: In a Moving Target Indicator (MTI) radar, a delay line canceller is used to eliminate clutter from fixed targets. To correctly cancel the fixed targets from consecutive pulses, the time delay introduced in the delay line must be exactly equal to one Pulse Repetition Period (PRP), not one half of it. Therefore, statement (c) is false.