Abstract: A local oscillator outputs a local oscillator signal that provides an upper side heterodyne mode or a lower side heterodyne mode for a received RF signal. A first converter converts the received RF signal into an IF signal, based on the local oscillator signal output from the local oscillator. An FM detector subjects the IF signal produced by conversion to detection. A first measurement unit measures a signal intensity of the IF signal before the IF signal is input to the FM detector. A second measurement unit measures a squelch voltage of a signal detected by the FM detector. A controller that controls the local oscillator based on the signal intensity measured by the first measurement unit and the squelch voltage measured by the second measurement unit.

Abstract: A local oscillator outputs a local oscillator signal that provides an upper side heterodyne mode or a lower side heterodyne mode for a received RF signal. A first converter converts the received RF signal into an IF signal, based on the local oscillator signal output from the local oscillator. An FM detector subjects the IF signal produced by conversion to detection. A first measurement unit measures a signal intensity of the IF signal before the IF signal is input to the FM detector. A second measurement unit measures a squelch voltage of a signal detected by the FM detector. A controller that controls the local oscillator based on the signal intensity measured by the first measurement unit and the squelch voltage measured by the second measurement unit.