US Patent 8125375 Radar

A radar that detects the presence or absence of interference when detecting a target based on a frequency spectrum of a beat signal of a transmission signal and a reception signal. Whether or not the number of peaks exceeding a noise threshold in the frequency spectrum exceeds a predetermined number is determined. According to the determination result, the presence or absence of interference on the beat signal is detected. If “interference exists”, the threshold for extraction of target peaks that appear on the frequency spectrum is increased. This allows detection of the presence or absence of a spike noise superposed on the beat signal to be performed more certainly, thereby enabling processing according to the presence or absence of interference.