An Analytical Formulation for Phase Noise in MEMS Oscillators
An Analytical Formulation for Phase Noise in MEMS Oscillators
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DOI：
10.1109/tuffc.2014.006511
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发表时间：
2014-12-01
影响因子：
3.6
通讯作者：
Seshia, Ashwin A.
中科院分区：
文献类型：
--
作者：
Agrawal, Deepak K.;Seshia, Ashwin A.
近年来，低噪声微机电系统振荡器的设计引起了人们的极大兴趣。本文提出了一种新的MEMS振荡器噪声分析公式，该公式包含了基本谐振器和放大器的非线性。通过求解二阶非线性随机微分方程，导出了振子噪声的解析表达式。该方法应用于基于静电寻址MEMS谐振器的方波振荡器的噪声建模，其中谐振器和振荡器电路非线性集成到单个建模框架中。通过考虑由此产生的振幅和相位关系，我们推导出谐振器非线性引起的附加噪声项。研究了振荡器的相位扩散，提出了相位扩散系数作为噪声优化的度量。提出的非线性相位噪声模型提供了对底层物理的分析见解，并为低噪声MEMS振荡器的设计优化提供了途径。
In recent years, there has been much interest in the design of low-noise MEMS oscillators. This paper presents a new analytical formulation for noise in a MEMS oscillator encompassing essential resonator and amplifier nonlinearities. The analytical expression for oscillator noise is derived by solving a second-order nonlinear stochastic differential equation. This approach is applied to noise modeling of an electrostatically addressed MEMS resonator-based square-wave oscillator in which the resonator and oscillator circuit nonlinearities are integrated into a single modeling framework. By considering the resulting amplitude and phase relations, we derive additional noise terms resulting from resonator nonlinearities. The phase diffusion of an oscillator is studied and the phase diffusion coefficient is proposed as a metric for noise optimization. The proposed nonlinear phase noise model provides analytical insight into the underlying physics and a pathway toward the design optimization for low-noise MEMS oscillators.