A high-frequency-signal switching circuit includes a first high-frequency-signal
path which includes first and second diodes connected in series with a high-frequency
amplifier stage therebetween, and a second high-frequency-signal path formed of
a third diode connected in parallel to the first high-frequency-signal path. A
switching-voltage supply section switches the high-frequency amplifier stage and
first and second diodes ON, and the third diode OFF, so that a high-frequency signal
is transferred through the first high-frequency-signal path, or switches the high-frequency
amplifier stage and first and second diodes OFF and the third diode ON, so that
a high-frequency signal is transferred through the second high-frequency-signal path.
