Automatic frequency control method and device for use in receiver

摘要

An automatic frequency control method for use in a receiver mixes a received signal and a local oscillator signal to produce an intermediate frequency signal and converts the intermediate frequency signal to a voltage signal. The voltage signal is converted to digital data which is then compared with a theoretical value, outputting frequency correction data which permits the difference between the digital data and the theoretical value to be minimized. The frequency of the local oscillator signal is controlled according to the frequency correction data so that the intermediate frequency signal becomes the normal frequency.