Radio receiver has intermediate frequency (IF) level detector that outputs attenuating factor signal based on which receiving field strength of antenna is controlled

摘要

A signal (A) received by an antenna (2) passes through a high frequency reception unit (12) and is combined with an IF signal (ZF) in a mixer (6). An IF level detector (10) outputs an attenuating factor signal. The receiving field strength of the antenna received signal is controlled based on the attenuating factor signal and the IF signal level to strengthen the IF signal.