RECEIVING FRONT END CIRCUIT, RECEIVING CIRCUIT AND COMMUNICATION EQUIPMENT USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a receiving front end circuit of low current consumption in which an IF output level is not remarkably lowered even under an unexpected strong input condition, and a receiving circuit for not generating errors in receiving level detection. SOLUTION: An average level detection circuit 10 detects the level of baseband output signals or the input signals of a mixer circuit. A smoothing circuit 11 removes AC components from the output signals of the average level detection circuit 10. A reference comparator circuit 12 outputs level suppression signals when the output signals of the smoothing circuit 11 exceed a prescribed reference voltage. A limiter circuit 13 suppresses the bias current of the mixer circuit by controlling a bias circuit 14 when the level suppression signals are outputted from the reference comparator circuit 12. COPYRIGHT: (C)2006,JPO&NCIPI