FM SIGNAL DEMODULATION METHOD AND DEVICE THEREOF

摘要

There are provided an FM signal demodulation method and a device thereof capable of easily modifying sensitivity as an FM signal demodulator without changing the response speed and using a differentiation calculation having no waveform distortion. A reference signal having frequency which is a center frequency of the FM signal to be demodulated and a phase different by 90 degrees to each other is frequency-mixed with the FM signal inputted, which are converted to intermediate frequency signal I and Q having a phase different by 90 degrees to each other around 0 Hz. The intermediate frequency signals I and Q are multiplied across each other by signals dI and dQ obtained by time-differentiating the I and Q. A difference between the multiplied signals I.dQ and Q.dI, i.e., I.dQ - Q.dI is output.