High-precision Phase Measurement System

In information engineering, how to obtain accurate data of this phase has become increasingly important. It's unlike traditional measurement of phase voltage and current signals or the measurement of temperature. Firstly, as the information of phase difference is inherent in the specific voltage or current, how to remove the impacts of voltage, current or frequency changes on the phase difference measurement is an important question. Secondly, as phase difference is a comparison variable, to obtain effective phase difference between two signals, the measured two signals should have the same frequency. Moreover, the impacts of amplitude changes or other parameters result on the measurement. Therefore, how to reliably measure the phase difference between two signals is an important research topic. Phase difference measurement system requires the traditional use of multiple small and medium scale integrated circuits, circuit complexity of the system not only for narrow frequency range, can only measure the frequency or low frequency signal, and measure the phase difference of accuracy is not high, so in the practical application the deficiencies.This paper introduces the main chip phase measurement, differential amplifier, analog-to-digital converter (ADC). On this basis, we designed phase the main chip and a microcontroller as the core of the hardware system. After measured, the phase difference between two signals with the same frequency is converted into voltage signals, in which the voltage and the phase difference have a linear relation. After amplified, the phase difference in voltage form is sent in one peak-peak demodulator. The demodulated signals are further converted into digital signals by the ADC. Finally, after compensating the measurement errors with signal processing algorithm, a measurement accuracy of 1 deg is obtained.