RECEIVING CIRCUIT FOR A PORTABLE TELEPHONE SET

摘要

An unnecessary wave suppressing means suppresses unnecessary waves included in a reception high frequency signal in a frequency band that is changed in accordance with a switching signal. The unnecessary wave suppressing means changes the pass band by inserting a notch into a pass band at a range where a signal is to be suppressed, changing the pass band width so as to exclude a suppression band, retaining a plurality of narrow pass bands for respective frequency bands used and switching among those narrow pass bands in accordance with a frequency band of a receiving signal, or continuously changing the pass band by using a tuning filter.