To satisfactorily prevent a pulse-modulated high-frequency signal for transmission from being outputted to a reception system owing to internal reflection, etc. with respect to a high-frequency transceiver.

This high-frequency transceiver is equipped with a high-frequency oscillator 1, a branching unit 2, a modulator 3, a circulator 4, a transmit-receive antenna 5, and a mixer 6A. The mixer 6A is equipped with diodes 6a1 and 6a2 as first and second elements for high-frequency detection, respectively, a bias circuit C1 for passing bias currents therethrough, and switches 6b1 and 6b2 connected to the bias circuit C1 for keeping an intermediate frequency signal from being outputted by cutting off the bias currents in an open state and causing the frequency signal to be outputted by passing the bias current therethrough in a closed state when the modulator 3 has become stable in a non-outputting state. Since the bias current is cut off at a prescribed time to appropriately cut off the frequency signal including noise, an S/N (signal to noise) ratio is increased to enhance reception performance.

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