To obtain information in addition to the distance and relative speed of a target by providing an FM-CW radar comprising an oscillator, a power distributing means, an antenna, a frequency converter, a distance and relative speed detecting circuit, and a code detecting circuit.
A first antenna 8a delivers a transmission signal toward a target 13 with a radio wave reflector where the reflection amount of high frequency modulation signal is time variant depending on code information. A second antenna 8b receives a reflection signal from a target 13 with a radio wave reflector and delivers a receiving signal. A frequency converter 9 receives a receiving signal and a local oscillation signal and delivers a video signal having sum and difference frequency of both signals. A distance and relative speed detecting circuit 10 analyzes the video signal subjected to Fourier transform on the frequency axis and detects information on the distance and relative speed of the target 13 with a radio wave reflector, and the like. A code detecting circuit 12 analyzes the video signal on the time axis, compares the level of the video signal with a threshold level and encodes the video signal thus detecting the code information on the target 13 with a radio wave reflector.
FURUYA TERUO
TSUBOTA YOSHIHIRO
SATO MASATO
