Digital phase meter

A digital phase meter is described which operates on the basis of direct phase measurement without intermediate amplitude measurement and subsequent mathematical transformations. Such a phase meter can be optimized on the basis of the cross correlation function for two harmonic input signals of the same frequency. The effect of input noise on the measurement is determined according to the theory of optimal phase measurements. The algorithm of phase determination is implemented by two correlation channels, a signal shaper, a generator of counting pulses, and a code to phase converter. Each correlation channel includes generator of orthogonal reference signals, four coincidence circuits, an inverter, and a reversible counter. All components, except the signal shaper, are built with most modern logic elements. Elimination of amplitude processing has greatly simplified the equipment and greatly reduced the error.