HIGH-SENSITIVITY SEARCH SIGNAL DETECTION RADAR SYSTEM

摘要

PURPOSE:To improve the probability for capturing a reception signal by sweeping the reception band according to a saw-tooth wave of a frequency sweeping rate which is slightly different from the frequency sweeping rate of the reception signal. CONSTITUTION:A seep rate K2 of a saw-tool wave 21 and a chirp frequency sweeping rate K1 of an input signal IF are slightly shifted and matched, thus fully increasing a time width tdet: BW/(K1-K2) (BW is the bandwidth of BPF5) where the signal IF is detected. Since the BPF5 following the signal IF is a filter with a fixed center frequency, thus enabling the filter to be manufactured easily. Also, an equalizer 13 can be inserted owing to the fixed frequency, thus improving range side lobe which becomes a problem on pulse compression. An output signal Sv of a frequencyvariable voltage-controlled oscillator 10 can be frequency-converted as a local signal before and after the BPF5, thus enabling the inside of a broken line dtf to be equivalent to a dynamic tracking filter DTF of a basic radar system.