Patent ID: 6121917
Filing Date: 2000-09-19
Classification: G01S

Abstract:
An FM-CW radar comprising a transmit section for radiating a transmit signal resulting from frequency modulation of a carrier wave, a receive section for receiving a receive signal, which is the transmit signal reflected from an object, in an angular range including a plurality of beam direction angles and for generating a beat signal by mixing said receive signal with part of said transmit signal, and a signal processing section for detecting a range to said object and a relative velocity of said object, based on a frequency of said beat signal,wherein said receive section has an array antenna in which a plurality of element antennas are arrayed in a plurality of channels, and a plurality of mixers for mixing the receive signal with part of said transmit signal for each of said element antennas to create a beat signal of each channel of said plurality of channels, andwherein said signal processing section comprises:a first means for executing analog-to-digital conversion of said beat signal of each channel into a digital beat signal of each channel and storing said digital beat signal of each channel;second means for effecting a Fourier transform process on the digital beat signal of each channel to obtain Fourier transform data of each channel having beat frequency spectrum information;third means for effecting a phase shift process according to said plurality of beam direction angles on said Fourier transform data of each channel and thereafter synthesizing the Fourier transform data of each channel for every beam direction angle to obtain Fourier transform data of each beam direction angle having beat frequency spectrum information of each beam direction angle; andfourth means for calculating the range to said object and the relative velocity of said object, based on said Fourier transform data of each beam direction angle.