AGC CIRCUIT OF FM FRONT-END

摘要

According to this invention, there is disclosed an AGC circuit of an FM front-end portion, including an attenuator (11) for attenuating an input signal in accordance with a level of a first signal, an amplifier (13) for amplifying the input signal in accordance with a level of a second signal, a first input amplitude control circuit (15) for outputting third and fourth signals in accordance with a receiving electric field strength of a receiver, a receiving electric field detecting circuit (21) for outputting a fifth signal in accordance with an amplitude of an IF signal in the receiver, and a second input amplitude control circuit (22) for adjusting levels of the first and second signals by changing the third and fourth signals in accordance with the fifth signal. IMAGE