Precise all-digital frequency detector for high frequency signals

A fully digital and simple to implement frequency detector for use with high frequency signals is presented. The new frequency detector can detect small phase movements of much less than one cycle, even though the frequency detector is clocked at a low rate. Existing digital techniques can only detect phase movements of more than one cycle, or require clock rates much higher than the frequency of the signal. The operating limits of the new frequency detector are derived. Examples of the application of the new frequency detector are also given.