Responder for simulation of radar target - permits target radial speed and distance to be retransmitted to radar

摘要

A responder for radars of all types transmits pulses in response to signals received. Target radial speed is simulated by phase modification of retransmitted carrier relative to the transmitted carrier signal and the distance is determined by a delay. Signal received via antenna and duplexer is transposed to intermediate frequency utilising local oscillator signal is amplitude limited and a phase sensitive detector produces sine and cosine w.r.t. a stable oscillator. Digital processing circuit memories and modifies these signals in conjunction with operator control Doppler frequency signal. A modulator ensures retransmitted signal passing via a mixer is coherent with signal received by phase detector.