摘要 |
A frequency demodulator of the present invention includes: an amplification section for receiving a frequency-modulated signal and amplifying the frequency-modulated signal based on a gain so as to produce a digital signal having a predetermined level and an inverted signal of the digital signal; a digital demodulation section for receiving the digital signal and frequency-demodulating the digital signal; an amplitude detection section for receiving the digital signal and the inverted signal of the digital signal, and detecting maximum amplitude values of the digital signal and the inverted signal for a predetermined period of time so as to produce an amplitude signal in proportion to the maximum values; and a gain controlling section for varying the gain based on the amplitude signal.
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