METHOD AND DEVICE FOR MEASURING INSTANTANEOUS FREQUENCY OF FM SIGNAL

摘要

PROBLEM TO BE SOLVED: To easily and accurately measure the instantaneous frequency of an FM signal needed for FM demodulation by providing a instantaneous frequency calculating means which gives an instantaneous frequency by processing a digital FM signal by performing mathematical operations on the basis of a plurality of digital FM signal samples, etc. SOLUTION: The device is equipped with the instantaneous frequency calculating means which gives the instantaneous frequency by processing the digital FM signal by performing mathematical operations on the basis of a plurality of digital FM signal samples, etc. This device is equipped with a sampling means 10, the instantaneous frequency calculating means 20, and a low-pass filter means 30. An analog FM modulated signal 01 is sampled by a sampling means 10 at specific sampling intervals to obtain a digital FM signal 11. The instantaneous frequency 21 is calculated by an instantaneous frequency calculating means 20 on the basis of the digital FM signal 11. This instantaneous frequency 21 is filtered by the low-pass filter means 30 finally to obtain a filtered instantaneous frequency 31.