A sample-and-hold-based sine wave phase measurement system

In this paper, a new prototype of a Phase Measurement System (PMS) is presented. The PMS uses a Sample & Hold (S&H) circuit-based architecture, and it is capable of performing phase measurements with very low uncertainty over a wide bandwidth. The prototype covers a frequency range from 100 Hz to 100 MHz, and it consists of three main subsystems: (i) a bank of four S&H circuits, (ii) a pulse train signal generator with coarse and fine delay control, and (iii) a data acquisition circuit followed by digital signal processing. The paper describes the method and system-level architecture of the PMS, as well as its capabilities. Experimental results show that the PMS can provide high-accuracy time measurements from high-accuracy amplitude measurements. For a sinewave frequency of 10 MHz, the maximum standard deviation obtained was 0.019°, while for a frequency of 100 MHz, the maximum standard deviation was 0.73°. These results represent a significant improvement compared to the previous PMS prototype and reference measurement instrumentation.