| 摘要 |
<p>PROBLEM TO BE SOLVED: To detect the small frequency change or amplitude change of a radar signal to identify the radar signal by providing a delay means for delaying a pulse modulation signal, and a multiplying means for multiplying the pulse modulation signal by the delay signal. SOLUTION: An IF signal (a pulse modulation signal) from an LPF 13 of a radar signal receive part is delayed by the specified time by a delay means 20. A mixer 21 is a multiplying means for multiplying the IF signal from the SPF 13 by the delay signal from the delay means 20. The LPF 22 eliminates a high frequency components from the output signal of the mixer 21, and a capacitor 23 eliminates a direct current component from the output of the mixer 21. An identifying means 24 identifies the pulse modulation signal on the basis of the output signal of the capacitor 23 and outputs it as an identification signal. In the case of inputting a signal with micro change in frequency and its delay signal into the mixer 21, a beat signal, that is, a signal corresponding to the frequency difference of both signals, appears. This signal component is extracted by the LPF and capacitor to detect the micro change of frequency.</p> |
