Patent ID: 6445336
Filing Date: 2002-09-03
Classification: G01S

Abstract:
A radar device comprising:an oscillator producing a frequency-modulated electromagnetic wave; a transmitting antenna radiating the electromagnetic wave as a transmission signal; a reception antenna receiving, as a reception signal, a reflected signal which is produced when the transmission signal is reflected from the obstacle; a directional coupler which extracts a local signal from the electromagnetic wave produced at the oscillator; a mixer mixing the local signal fed from the directional coupler and the reception signal fed from the reception antenna; an AC amplifier for AC-amplifying a mixing signal produced at the mixer; a switching demodulation circuit producing a beat signal comprising a frequency component representing a relative speed relative to the obstacle and a frequency component representing a relative distance to the obstacle; a switching circuit modulating the reception signal in switching mode for being fed to the mixer; and a high pass filter disposed between the mixer and the AC amplifier.