Prototype of high accuracy single input phase measurement instrument

Abstract

A prototype implementation of a phase measurement method (PMM) for a sine-wave signal delivered at the output port of a generator and its experimental assessment is presented. This PMM is capable of measuring the output phase of a sine-wave signal respect to a reference phase with high accuracy and a very low uncertainty. A description of the prototype PMM, and its mathematical model are given in the paper. The prototype operates over the frequency range of 100Hz to 10MHz and it is composed from three main subsystems: (i) the sampling circuit, (ii) the pulse-train signal generator, and (iii) the data acquisition and digital signal processing. A laboratory test bench was realized to assess the phase measurement repeatability of the prototype, and a maximum phase standard deviation of 0.021° measured at 25°C was obtained for the output frequency of 10MHz, where the phase uncertainty decreases with decreasing frequency.