| 摘要 |
PURPOSE:To improve deterioration in noise reduction performance due to a narrow FM modulation band width and in response due to the narrow band resulting from high sensitivity processing of the FM receiver. CONSTITUTION:An FM reception signal is subjected to frequency conversion by a multiplier 2 receiving a frequency signal from a local oscillator 3 and its output is directly inputted to a BPF 21 and inputted to other BPFs 22-2n after subjected to phase correction by phase shifters 12-1n, and then the output signal is divided into prescribed frequency bands. Each band split signal is weighted by weighting circuits 31-3n and the result is synthesized by an adder 4 and the synthesis signal is detected by an FM detection circuit 5 and a demodulation signal is outputted to an output terminal 8 via an LPF 6. The demodulation signal is inputted to voltage comparators 41-4n and the comparators give a weighting control signal to each weighting circuit. |
