THREE-FREQUENCY PHASE DIGITIZING SYSTEM AND METHOD OF THREE-PHASE DIGITIZING AN INTERFEROMETER SIGNAL USING THE SAME

摘要

A phase digitizing system includes an analog-to-digital converter (ADC), multiple phase accumulators and a processing device. The ADC generates sample segments of digital signal waveform samples based on an analog composite input signal received in a measurement channel, the composite input signal includes a first signal having a first frequency F1 and a second signal imported from a reference channel having a second frequency F2. The processing device is coupled to the phase accumulators, and digitally processes each sample segment with outputs of the phase accumulators, and continually generates digital phase data The processing device further provides increment values to each of the phase accumulators based on the digital phase data, causing an output of a first phase accumulator to represent an instantaneous phase of the first signal, and an output of a second phase accumulator to represent an instantaneous phase of the second signal.