RF APPARATUS

摘要

An RF apparatus with a built-in FM demodulator, which improves threshold effectively. This apparatus comprises an FM demodulator, a circuit (114) for detecting the FM modulation factor from a demodulated output, an input signal intensity detector (103), a circuit (110) for combining the output supplied from the FM modulation factor detector (114) through a switch (109) and the output from the input signal intensity detector (103) to generate a control signal, wherein the gain is varied by the output of the circuit (110). An optimum demodulation band width is obtained according to the modulation factor of the input signal, and the threshold can be improved effectively without generating a large noise due to a synchronization error.