Vehicle-mounted radar apparatus

摘要

A vehicle-mounted radar apparatus comprises: a transmitting-receiving device 8 including an FM modulator 1 for generating an FM modulation signal, a voltage controlled oscillator 2 for generating an electromagnetic wave subjected to FM modulation by the FM modulation signal, a transmitting antenna 4 for transmitting the FM-modulated electromagnetic wave, a receiving antenna 6 for receiving the electromagnetic wave reflected by a preceding vehicle 5, and a mixer 7 for mixing the FM-modulated electromagnetic wave and the electromagnetic wave from the receiving antenna and for outputting a beat signal; a signal processor 9 for computing a relative velocity and a relative distance with respect to the preceding vehicle on the basis of the beat signal; and a scanning mechanism 12 for rotatively driving the transmitting-receiving device, wherein a modulation period of the FM-modulated electromagnetic wave and a rotation angle range of the scanning mechanism are changed in accordance with the relative velocity and the relative distance with respect to the preceding vehicle.