Study On The Influence Of Frequency Processing And Phase Processing Methods On The Stability Of Frequency Source

Stability is an important technical indicator of frequency source.The traditional method of improving the stability index is mainly through the optimization of the physical chamber of the atomic clock.In today's situation of optimization and maturity,there is often little effect.Phase processing are used in active atomic clocks.The regularity of active atomic clocks stability change is 1/?.Frequency processing are used in passive atomic clocks.The regularity of passive atomic clocks stability change is 1/???.It can be seen that the change rule of frequency source stability is related to processing method.The phase information of the passive clock is difficult to obtain because of the complexity of the signal relationship in the system and the uncertainty of the phase of the atomic energy level transition.The frequency processing is used in all passive atomic clocks.That leads to the change in the stability of 1/???.Therefore,exploring the influence of frequency processing and phase processing on stability is a feasible way to improve the stability index.that provides a feasible direction for the transformation of passive atomic clocks from frequency processing to phase processing.Through the exploration of the phase phenomenon of complex periodic signals,this paper has deepened the understanding of the phase phenomenon,widened the application scope of phase processing and provided a theoretical basis for the phase utilization in complex systems.In this paper,a high precision frequency source,rubidium atomic clock,which uses frequency processing method is taken as an example.The complex frequency relation and the phase relation under the complex frequency relation are analyzed in detail.Through the derivation of the formula after modeling,the formula of getting continuous frequency difference information from the time difference information between the special phase feature point of light detection signal,maximum energy level transition probability point,and zero crossing point of low frequency signal is obtained.Using the theory of virtual reconstruction,the frequency source phase information is finally recovered.That makes the implementation of the phase process come true.This paper designs an improved scheme of rubidium clock combined with digital A/D conversion technology phase processing mode.The implementation and measurement of hardware are also carried out.According to the analysis of the experimental results,the second level stability of the reformed rubidium atomic clock is close to 2*10^-12.Up to half an order of magnitude.Compared with the stability rule under frequency processing mode,it is proved that the phase processing method can make the stability of frequency source have a higher index.Data analysis shows that the complementary nature of the crystal oscillator and the physical body is expected to become a new direction for the transformation of passive atomic clocks.The detailed error analysis of the experimental results provides an important reference for further improving the phase processing experiment.This paper explores the influence of phase processing and frequency processing for the stability of frequency sources.Combining the analysis and utilization of the phase phenomenon of the complex time-frequency system,it is concluded that the phase processing mode is a better choice for complex time-frequency system.The feasibility of the phase processing method in the atomic clock is preliminarily verified by actual experiments.This provides a new direction for improving the stability index of all passive atomic clocks.