基于调制转移光谱、吸收鉴频和色散鉴频技术的应用，根据被动型氢原子钟的工作原理，对单频调制的微波探测信号的氢原子跃迁鉴频和微波腔谐振鉴频过程进行了详细的理论分析和数学推导。在此基础上仿真得到了鉴频曲线与不同调制深度对应的误差信号幅值的关系，并与实验测试结果进行对比分析，验证了被动型氢原子钟单频调制的调制解调原理的推导过程，得到了使被动型氢原子钟短期稳定度最好的调制深度；上述分析过程为被动型氢原子钟单频调制技术提供了性能优化的理论基础和依据，为电路方案改进提供了设计原理。

On the basis of the technological application of modulation transfer spectroscopy, absorption frequency discrimination, and dispersion frequency discrimination, according to the operating theory of passive hydrogen maser, the theoretical analysis of the process where a single frequency modulation signal carries out frequency discrimination of hydrogen transition and of the microwave cavity resonance are mathematically derived in details. The relation of frequency discrimination curves and the error signal amplitudes with different modulation depths from simulation is obtained by simulation, and the simulated results are compared with the experimental results. The simulated and experimental results verify the effectiveness of the derivation process, and the modulation depth is acquired, which endows the short-term stability of passive hydrogen maser with the best performance. The analysis procedure provides the theoretical basis of performance optimization for passive hydrogen maser based on single frequency modulation, and it provides the design principle of project improvement for electronic circuit.