A Novel MSPLL-Based Method for Frequency Synthesis in Hydrogen MASER.

Area of Science:

• Atomic Clock Technology
• Frequency Synthesis
• Phase-Locked Loop Systems

Background:

• Frequency synthesis is crucial for atomic clock performance, requiring excellent short-term stability and low phase noise.
• Conventional single-PLL systems have limitations in achieving the desired stability for hydrogen maser atomic clocks.

Purpose of the Study:

• To present a novel master-slave-based phase-locked loop (MSPLL) method for frequency synthesis in hydrogen maser atomic clocks.
• To improve the master oscillator's stability and reduce jitter by coupling two phase-locked loops.

Main Methods:

• Utilized a master and slave phase-locked loop (PLL) with coupled direct digital synthesizers.
• Developed a novel mathematical model for the MSPLL to analyze settling time and jitter variance.
• Experimental validation of the proposed design and its performance metrics.

Main Results:

• Achieved a phase settling time adjustable between 689 μs and 811 μs.
• Demonstrated phase noise of ≤-114 dBc/Hz at 1 Hz offset.
• Obtained short-term stability of approximately (7.66 × 10-12) τ-1/2 at 1 s, closely matching the physics subsystem.

Conclusions:

• The proposed MSPLL design offers superior short-term stability, being an order of magnitude better than existing methods.
• This approach effectively transfers the hydrogen maser's frequency stability to the master oscillator.
• The MSPLL method provides a robust solution for high-performance frequency synthesis in atomic clocks.