Post detection integration method and apparatus for pulse compression radar utilizing surface acoustic wave (SAW) matched filters

摘要

Received expanded radar pulses pass through a surface acoustic wave (SAW) weighted filter (64) for sidelobe suppression, and then into a SAW tapped delay line (66). The pulses appear at the taps (66a,66b,66c) of the delay line (66) coarsely aligned in time, pass through individual SAW matched filters (68,84,86,88) for compression and envelope detectors (70,90,92,94) for demodulation, and then into a summer (74) for post detection integration. Individual frequency shifters (78,80,82) are provided between the delay line taps (66a,66b,66c) and the matched filters (84,86,88) for shifting the center frequencies of the pulses and thereby the propagation delays through the matched filters (84,86,88) to provide fine alignment of the pulses in time. The delays through the individual delay line taps (66a,66b,66c) and the frequency shifts of the frequency shifters (78,80,82) are adjustable "on the fly" to compensate for variation of pulse repetition rate (PRF) and interpulse jitter.