| 摘要 |
PROBLEM TO BE SOLVED: To detect and correct frequency modulation characteristic using a simple configuration and at a low cost in a radar apparatus. SOLUTION: A modulated-signal generation circuit 29 frequency-modulates a VOC 24 by triangular waves indicated in Fig. (b), so as to operate as an FM-CW type radar 21. A signal processing circuit 30 generates a detection modulating signal, indicated in Fig. (c) from the circuit 29 so as to be given to the VOC 24. A high-frequency signal, which is frequency-modulated by the VOC 24, is transmitted as radio waves from a transmitting antenna 22, and it is reflected by a target, so as to be received by a receiving antenna 24. On the basis of the received signal and the high-frequency signal, a beat signal is obtained by a mixer 26, and a frequency shift with reference to a voltage V1 is detected on the basis of the frequency of the beat signal. When the voltage V1 of the detected modulating signal is changed over, a frequency shift corresponding to a different voltage V1 is obtained, and the frequency modulation characteristics can be detected. |
