Patent ID: 6980775

Claim:
An automatic frequency control (AFC) system comprising: a tunable transceiver for receiving and transmitting signals within a predetermined frequency range; an adaptive detector for comparing an incoming sample from the tunable transceiver to an adaptive maximum deviation threshold for determining if a sample from the tunable transceiver should be used for the direct current (DC) component of the AFC; an offset detector for determining a difference in frequency between a receive signal frequency and a transceiver operating frequency; a control processor for utilizing information from the offset detector to reduce the difference in frequency by moving the passband of the tunable transceiver towards the receive signal frequency where the control processor defines an accuracy limit threshold based upon the proximity of the receive signal frequency to the transceiver operating frequency, a maximum correction threshold based upon a predetermined maximum frequency correction limit, and a hardware tuning threshold based upon a predetermined tunable transceiver specification; and further wherein the accuracy limit threshold, maximum correction threshold and the hardware tuning threshold are used for efficiently controlling the predetermined frequency range of the tunable transceiver for efficient operation.