Fm-cw radar method

PURPOSE: To reduce interference between radar mounted automobiles to improve reliability by controlling switching frequency for turning ON/OFF a transmission signal or transmission frequency so that they fluctuate at each or they are different from device to device. CONSTITUTION: In a first method, (n) combinations Fn are possible by varying transmission frequency of a radar. Or by switching the transmission frequency Fn at (m) repetition intervals, (n×m) combinations of identification of radar waves (Fn×m) are provided. In a second method, if an interference radar signal is input from a reception antenna 18 to a receiving part, a measuring part 15 measures switching frequency of ON/OFF repetition for the signal and informs it of a control part 16. The control part 16 checks if there is a deviation of a predetermined value or more between the switching frequency of the interference radar signal and that of a self device, and when the deviation is within a constant value, the control part 16 corrects the switching frequency of the self device and center frequency of a bandpass filter 14 so that their deviation is equal to or greater than the constant value. COPYRIGHT: (C)1993,JPO&Japio