| 摘要 |
A digital frequency detector (10) and method for digitally detecting arbitrarily small phase changes between a signal waveform and a reference waveform. Both the reference waveform and the signal waveform are sampled at a rate related to the clock frequency fc, and separately fed into two arrays of simple frequency detectors (12, 14). Each simple frequency detector in each array has a different starting phase with respect to the reference waveform and the signal waveform respectively. Phase slips between the reference waveform and the sampling frequency and phase slips between the signal waveform and the sampling frequency are measured by the detector arrays (12, 14). These phase slips, called "slip events", are combined in circuit (16) which produces an output indicative of phase slips between the reference waveform and the signal waveform. Using this phase slip information, the instantaneous frequency difference between the signal and reference waveforms can be determined.
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