A Passive Phase Noise Cancellation Element

TL;DR

This paper presents a novel passive device using coupled nonlinear resonators to significantly reduce phase noise in oscillators, enhancing frequency stability without active feedback.

Contribution

It introduces a new passive phase noise cancellation element based on coupled nonlinear resonators driven parametrically, demonstrating immunity to oscillator noise at specific operating points.

Findings

Device achieves noise immunity at certain operating points

Thermal noise effects analyzed for fundamental limits

Potential for improved oscillator frequency stability

Abstract

We introduce a new method for reducing phase noise in oscillators, thereby improving their frequency precision. The noise reduction device consists of a pair of coupled nonlinear resonating elements that are driven parametrically by the output of a conventional oscillator at a frequency close to the sum of the linear mode frequencies. Above the threshold for parametric response, the coupled resonators exhibit self-oscillation at an inherent frequency. We find operating points of the device for which this periodic signal is immune to frequency noise in the driving oscillator, providing a way to clean its phase noise. We present results for the effect of thermal noise to advance a broader understanding of the overall noise sensitivity and the fundamental operating limits.