Oscillator PM Noise Reduction From Correlated AM Noise

Area of Science:

• Electrical Engineering
• Physics
• Materials Science

Background:

• Phase modulation (PM) noise is a critical parameter in oscillator performance, affecting signal integrity.
• Vibration can induce significant PM noise, limiting oscillator applications in dynamic environments.
• Existing noise reduction techniques often fall short under vibration or steady-state conditions.

Purpose of the Study:

• To develop and demonstrate a novel technique for reducing PM noise in oscillators.
• To address both steady-state and vibration-induced PM noise.
• To improve the performance of quartz-MEMS oscillators.

Main Methods:

• Utilizing the correlation between phase modulation (PM) noise and amplitude modulation (AM) noise.
• Generating a control voltage proportional to correlated AM noise.
• Implementing a feedforward architecture for PM noise correction.

Main Results:

• Achieved a 10-15 dB improvement in PM noise over one decade of offset frequencies.
• Demonstrated a reduction in vibration sensitivity by more than a factor of five.
• Successfully corrected for both steady-state and vibration-induced PM noise.

Conclusions:

• The novel feedforward technique effectively reduces PM noise in oscillators.
• This method offers significant improvements in PM noise and vibration sensitivity for quartz-MEMS oscillators.
• The approach is applicable to various oscillator types susceptible to AM-PM noise correlation.