Patent ID: 7528768

Claim:
A radar device for emitting a wave into space, receiving the wave reflected by an object present in the space, and performing signal processing on the received wave to measure the object, comprising: an oscillator for generating the wave at a plurality of transmission frequencies; a transmitting antenna for emitting the wave generated from the oscillator into the space; a receiving antenna for receiving an incoming wave; a receiver for detecting the received wave received by the receiving antenna to generate a real received signal; a Fourier transform unit for performing a Fourier transform on the real received signal generated from the receiver in a time direction; a spectral peak detecting unit for receiving an input of a result of the Fourier transform from the Fourier transform unit to extract peak complex signal values of Doppler frequency points at which an amplitude is maximum; a distance calculating unit for storing the peak complex signal values from the spectral peak detecting unit, which are obtained by using the plurality of transmission frequencies, and for calculating a distance to the reflecting object based on the stored peak complex signal values to output the obtained distance as a measured distance value; a distance determining unit for determining validity of the measured distance value obtained from the distance calculating unit and outputting the measured distance value calculated in the distance calculating unit and the Doppler frequency detected in the spectral peak detecting unit according to a result of determination; a pulse modulator for performing pulse modulation on the wave generated in the oscillator; and a distance selecting unit for selecting real received signals having the same difference between a transmission time and a reception time from among real received signals from the receiver obtained by transmission of a plurality of pulses and outputting the selected real received signals and for outputting a distance estimate corresponding to the difference between the transmission time and the reception time, wherein: the transmitting antenna emits the wave having passed through the pulse modulator into the space; the Fourier transform unit performs the Fourier transform on the real received signals selected to be output from the distance selecting unit; and the distance determining unit comprises a distance range determining unit for comparing the distance estimate obtained in the distance selecting unit and the measured distance value obtained in the distance calculating unit with each other to output the measured distance value calculated in the distance calculating unit and the Doppler frequency calculated in the spectral peak detecting unit only when a difference obtained by the comparison is equal to or smaller than a predetermined value.