Design And Implementation Of Frequency Standard Phase Comparison Technology Based On Dual-phase Detecting

With the development of science and related time-frequency science and technology, precise measurement of time-frequency parameters has become research hotspot. Due to the late start in the field of time-frequency and the domestic political factors and other reasons, there exists a gap between the current domestic time and frequency measurement and European and American countries. To narrow the technology gap and overcome the technical barriers and use a new measurement perspective to measure the time-frequency parameters, we design a frequency standard comparison system based on the phase of dual-phase coincidence detecting technology.First, this paper discusses the advantages and disadvantages of the traditional method for frequency standard comparison. Through the study of these methods, we have proposed the phase coincidence theory and related concepts, made a detailed analysis of and done a research into any desired frequency phase relationships between signals. After obtaining the least common multiple of the period, the greatest common factor frequency, quantization phase shift resolution and other related concepts, we expand them to actual frequency signals by studying the relationship between the phase change in actual measurement, and we have obtained the concept of equivalent phase-detecting frequency.In the study of the actual frequency, we find the equivalent phase-detecting frequency has generalized group period phase characteristics. Therefore, we have proven the equivalent phase-detecting frequency concept from the perspective of cluster, revealed their intrinsic principle and analyzed the advantages and disadvantages of this measurement technology based on the principle. By overcoming this shortcomings, we propose a dual-phase coincidence detecting based comparison system of standard frequency, which has the advantages of the double mixed difference method---i.e. it introduces an intermediary frequency and improves the measurement precision without the use of a mixer and reduces the introduction of noise and performance requirements for low frequency intermediate source. Meanwhile, the system also improves the traditional frequency standard comparison system which uses the method of counting and in this way, the counting error is eliminated. Furthermore, the dead zone phenomenon is resolved.Compared with conventional equipment, the device has modular thinking which consists of an input module, a measuring module, a control module and a data processing module. Various parts have their different duties, provide good interface functions, and reduce the complexity, cost and size of the system, and meanwhile it helps to improve the system in future.Finally, the paper makes an analysis of the measurement process and the results, giving the direction of the error and possible improvements.