PURPOSE: To downsize an apparatus and simplify adjustment by detecting Doppler frequency short of demodulation function and distance by means of digital signal processing in a coded CW radar apparatus.
CONSTITUTION: After a received signal is amplified by a wide band amplifier 14, it is frequency-converted into a base band signal by a mixer 6c to enable digitization of the received signal, and after it is converted into a digital signal by an ADD-converter 9, it is input into correlation processing circuits 11-1 to 11-N provided according to range cells (N pieces). Correlation is taken with pseudo random codes from a code delay circuit 10, the results are respectively input to corresponding FFT processing circuits 12-1 to 12-N to detect Doppler frequency for each range cell. An output of each FFT processing circuit has been all input to a distance detection circuit 13, so that the FFT processing circuit which detected the Doppler signal is identified, thereby detecting a distance to a moving target.
Hiroki Sugawara
Tatsuo Matsuno
Fumio Ishii
