High-precision frequency measurement system based on different frequency quantization phase comparison

Aiming at the requirements of phase comparison without frequency normalization, a high-precision frequency measurement system is proposed based on different frequency quantization phase comparison. Using group phase difference pulse in the least common multiple period, the period of frequency standard signal, the period of the measured signal and the pulse width of group phase difference can be respectively counted with the aid of FPGA technology. The obtained counter value is saved and sent to host computer. The measured frequency can be obtained by the data processing of the host computer. Experimental results show that the short-term frequency stability of the system better than E-12/s is achieved. Compared to the traditional frequency measurement system, the system have the advantages of wide measurement range, high frequency stability, low phase noise and low development cost. The system not only plays an important role in precise measurement physics fields such as high-precision transmission and comparison of time and frequency, measurement and suppression of phase noise, but also has a wider application in localization of spatial motion radiation source, satellite navigation equipment, precise time frequency measurement, communication, radar and other high-tech fields.