Automatic frequency control circuit and method of automatic frequency control

摘要

The present invention relates to the automatic frequency control circuit and the method of automatic frequency control. The automatic frequency control circuit for processing frequency control of a received signal frequency based on an incoming received signal comprises a first control circuit for processing frequency control based on a precision counter by using the incoming received signal and a second control circuit for processing frequency control based on a coarse counter by using the incoming received signal, wherein the first control circuit and the second control circuit are configured to be used interchangeably in response to the incoming received signal. By employing the circuit which directly counts the received signal and the circuit which counts the regenerative carrier signal in combination, the follow up range of the automatic frequency control circuit is thus expanded.