The Research And Realization Of Phase Comparison Between Signals With Different Frequencies

Among all the physical quantities, time and frequency are of the highest precision. As the key of time and frequency processing, phase process will directly affect the precision and performance of the whole system. In this paper, based on further understanding of changing regulation of the relationship between two period signals, we make further improvement of the conception of Equivalent Phase Comparison Frequency and so on. Conventional PLL needs frequency normalization before phase comparison, so complex frequency transformation circuits must be introduced. Phase comparison between two signals with different frequencies is used in the improved PLL, frequency transformation circuits are greatly simplified, and phase noise performance of the system is improved greatly. From experiments, the second stability can reach 2×10-13/s. This paper also probe into the circuit digital innovation of the active hydrogen atomic standard, circuit package of conventional active hydrogen atomic standard is analog, and the performances of the active hydrogen atomic standard will improved a lot after digital innovation, and also the phase noise performance is improvement greatly after the technique of phase comparison between two signals with different frequencies is applied, the cost of active hydrogen atomic standard will reduces a lot, so the application of active hydrogen atomic standard will be wider. If we make further research of phase comparison between two signals with different frequencies, the prospect of the application of phase comparison between two signals will be wider and wider.Lastly, we introduce some relevant applications of Equivalent Phase Comparison Frequency in simple, which can explain period natural phenomenon, and this may be useful to the forecast of natural calamities like earthquake and so on.