Angle digitizer with enhanced harmonic rejection

摘要

A device for converting time varying signals which represent sin theta and cos theta of an angle theta , where can take on values over a range, to an n bit digital signal. The range is typically 2 pi radians and is segmented into 2n+1-4 segments. The segments are mapped into 2n-1 amplitudes, and are encoded as the n bit digital signal. The invention is particularly useful as an angle digitizer where theta represents the phase difference between an input signal and a reference signal. As an angle digitizer, harmonic rejection is enhanced by the efficient use of the n bits to distinguish amplitude states as opposed to distinguishing merely phase states.