Patent ID: 7034743

Claim:
A radar comprising: a transmission-and-reception element arranged to transmit a transmission signal including an ascending-modulation section where a frequency gradually increases and a descending-modulation section where the frequency gradually decreases in an alternating manner and arranged to receive a reception signal including a reflection signal transmitted from an object; a frequency-analysis element arranged to obtain data on the frequency spectrum of a beat signal indicating the frequency difference between the transmission signal and the reception signal; a pair-extraction element arranged to extract a pair of first and second projection portions both caused by the object, where the first projection portion is observed in the frequency spectrum of a beat signal of the ascending-modulation section and the second projection portion is observed in the frequency spectrum of a beat signal of the descending-modulation section; a detection element arranged to detect at least one of a relative distance and a relative speed of the object based on frequencies of the two projection portions forming the pair; and a data input element arranged to input data on the moving speed of a moving object having the radar mounted thereon; wherein the pair-extraction element calculates the frequency difference between the projection portions observed in the frequency spectrums of the beat signals in the ascending-modulation section and the descending-modulation section based on the moving-speed data, where the frequency difference corresponds to the relative speed between the moving object having the radar mounted thereon and a stationary object, and extracts a pair that most closely corresponds to the frequency difference.