Systems Engineering and Electronics ›› 2026, Vol. 48 ›› Issue (5): 1706-1714.doi: 10.12305/j.issn.1001-506X.2026.05.26

• Guidance, Navigation and Control • Previous Articles     Next Articles

Research on precision taming method of crystal oscillators based on DDS frequency micro-step

Yikang HAO1, Kun LIANG1,2,3,*, Tian YU1, Junliang ZHAO1, Baoying WEI1, Yufeng LI1, Zhiyu HE4   

  1. 1. School of Automation and Intelligence,Beijing Jiaotong University,Beijing 100044,China
    2. State Key Laboratory of Advanced Rail Autonomous Operation,Beijing Jiaotong University,Beijing 100044,China
    3. Beijing Engineering Research Center for Electromagnetic Compatibility and Satellite Navigation,Beijing 100044,China
    4. Signal & Communication Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China
  • Received:2025-02-11 Online:2026-05-27 Published:2026-05-27
  • Contact: Kun LIANG

Abstract:

Aiming at the low frequency modulation accuracy of traditional voltage controlled frequency modulation methods for crystal oscillators, the taming and controlling and time holding method of oven-controlled crystal oscillators is investigated based on direct digital synthesis (DDS) frequency micro-step. By using the DDS module in the self-developed phase micro-stepper, frequency adjustment with a resolution of 0.6 μHz is achieved, providing conditions for improving the taming performance of crystal oscillators. The taming and controlling algorithm is based on the time transfer principle of global navigation satellite systems and the design of proportion-integral-differential (PID) control algorithm. By analyzing clock error data, the PID control model is optimized to effectively improve the taming and controlling performance of crystal oscillators. The experimental results show that the crystal oscillator taming and controlling algorithm based on DDS frequency micro-step can achieve a frequency stability of 1.09×10?13 and a time stability of 9.46×10?10 s with an average time of one day. In more than 99% of cases, the time deviation from the reference frequency source remains within ±25 ns, and the standard deviation of the time difference is 8.49 ns, proving the effectiveness of the proposed method.

Key words: oven-controlled crystal oscillator (OCXO), phase micro-stepper, direct digital synthesis (DDS), clock discipline, proportion-integral-differential (PID) control algorithm, global navigation satellite system (GNSS) time transfer

CLC Number: 

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