PURPOSE: To simplify circuit constitution and to remove faults appearing when received signals are mixed in one with attention paid to only phases, by using a variable delay line, using element differing in delay time according to a frequency, instead of an infinite phase shifter.
CONSTITUTION: Frequency converters 24 and 25 convert received signals S21 and S22 into intermediate frequency signals S24 and S25 of frequency fi with local oscillation signal S23 supplied from local oscillator 26. Signal S24, on the other hand, is input to synthesizing circuit 28 via intermediate frequency amplifier 27, and the other signal S25 to synthesizing circuit 28 via intermediate frequency amplifier 30 being delayed by continuous variable delay circuit 29 whose delay time is controlled. Amplifiers 27 and 30 have gains controlled by gain control signal S26 from synthesizing circuit 28 and both signals S24 and S25 are led out of amplifiers 27 and 30 as amplification output signals S24' and S25', which are mixed in one by synthesizing circuit 28, which obtain composite intermediate frequency signal S27.
MASUDA HAJIME
OGUCHI TAKUROU
