Application of Digital Frequency Modulation and Digital Servo to Passive Hydrogen Maser

The principle and composition of the passive hydrogen maser is introduced briefly,and an application of digital frequency modulation and digital servo to the passive hydrogen maser for improving the performance of the clock is expounded.The final test and analysis of the system are presented and the data indicate that the stability of the present system is much better than that of the original one.In order to further improve the performance,a new scheme based on DSP(digital signal processor) and FPGA(field program-mable gate array) is put forward for the servo system in this paper.