Frequency stability improvement for piezoresistive micromechanical oscillators via synchronization

Dong Pu,Xueyong Wei,Ronghua Huan

doi:10.1063/1.4978222

Dong Pu, Xueyong Wei + Show 1 more

Open Access

https://doi.org/10.1063/1.4978222

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Journal: AIP Advances	Publication Date: Mar 1, 2017
Citations: 21	License type: CC BY 4.0

Affiliation: Zhejiang University, Xi'an Jiaotong University

Abstract

Synchronization phenomenon first discovered in Huygens’ clock shows that the rhythms of oscillating objects can be adjusted via an interaction. Here we show that the frequency stability of a piezoresistive micromechanical oscillator can be enhanced via synchronization. The micromechanical clamped-clamped beam oscillator is built up using the electrostatic driving and piezoresistive sensing technique and the synchronization phenomenon is observed after coupling it to an external oscillator. An enhancement of frequency stability is obtained in the synchronization state. The influences of the synchronizing perturbation intensity and frequency detuning applied on the oscillator are studied experimentally. A theoretical analysis of phase noise leads to an analytical formula for predicting Allan deviation of the frequency output of the piezoresistive oscillator, which successfully explains the experimental observations and the mechanism of frequency stability enhancement via synchronization.

Highlights

Micro and nano mechanical resonators have been widely studied as a potential alternative to conventional quartz oscillators due to their advantages such as easier to miniaturize and to be integrated with electronics.[1,2] As frequency control or time reference devices, micromechanical oscillators have to own a better frequency stability
Special efforts have been invested in the reduction of phase noise and the improvement frequency stability in micro/nanomechanical oscillators via synchronization
In the previous work,[13] one micromechanical oscillator is synchronized to an external force and the phase noise spectrum is given analytically which implies that the largest phase noise reduction occurs in the center of the Shapiro step

Summary

Introduction

Micro and nano mechanical resonators have been widely studied as a potential alternative to conventional quartz oscillators due to their advantages such as easier to miniaturize and to be integrated with electronics.[1,2] As frequency control or time reference devices, micromechanical oscillators have to own a better frequency stability. This work, the synchronization phenomenon in a piezoresistive micromechanical clamped-clamped (C-C) beam oscillator is investigated and the observed improvement of frequency stability is studied. To entrain the oscillator into synchronized motion, an external harmonic signal of amplitude V ac[1] and frequency Ωs is applied on the other comb-drive electrode as a perturbation force to the beam oscillator.

Results

Conclusion