An experimental study of high gain parametric amplification in MEMS
An experimental study of high gain parametric amplification in MEMS
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DOI：
10.1016/j.sna.2009.11.016
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发表时间：
2010-08-01
影响因子：
4.6
通讯作者：
Burdess, James S.
中科院分区：
文献类型：
--
作者：
Hu, Zhongxu;Gallacher, Barry J.;Burdess, James S.
本文报道了应用于谐波强迫谐振MEMS传感器的参数放大的实验结果。在这项工作中，在10-100范围内的共振的强制响应的参数放大的静电驱动和感测陀螺仪传感器进行了研究。强调了与实际开发有关的几个重要因素。高增益参量放大的主要障碍是静电力的非线性，这对于高振幅振动变得重要。通过将谐波强制水平显著降低到刚好高于噪声阈值，已经实现了谐振响应的参数放大80倍，同时保持线性响应特性。结果表明，参数放大将频率响应函数的奈奎斯特图的形状从传统的圆形修改为明显的椭圆形。这被证明是由于一般不平等的贡献的频率响应函数的真实的和虚部，并与两个谐波激励之间的相对相位。此外，谐振附近的相变示出为参数放大谐振器较慢。参数放大谐振器的Q因子和带宽之间的关系进行了研究，并示出显着不同的线性谐振器与常系数。线性化的理论模型被用来确认和理解这些实验结果。还进行了进一步的实验测试，以研究在非线性动态响应开始时参数增益和参数激励之间的关系。(C)2009爱思唯尔有限公司版权所有。
This paper reports the experimental results of parametric amplification applied to a harmonically forced resonant MEMS sensor. In this work parametric amplification of the forced response at resonance in the range 10-100 is investigated for an electrostatically actuated and sensed gyroscopic sensor. Several important factors pertinent to practical exploitation are highlighted. The main obstacle to high gain parametric amplification is the nonlinearity of the electrostatic force which becomes significant for high amplitude vibration. By significantly reducing the harmonic forcing level to just above the noise threshold, parametric amplification of the resonant response by a factor of 80 has been achieved whilst maintaining linear response characteristics. It is shown that parametric amplification modifies the shape of the Nyquist plot of the frequency response function from the conventional circle to that of a pronounced ellipse. This is shown to be due to generally unequal contributions to both the real and imaginary parts of the frequency response function and is related to the relative phase between the two harmonic excitations. Furthermore, the phase transition around resonance is shown to be slower for the parametrically amplified resonator. The relationship between the Q-factor and the bandwidth for the parametrically amplified resonator is investigated and is shown to be significantly different from that of a linear resonator with constant coefficients. A linearized theoretical model is used to confirm and understand these experimental findings. Further experimental tests have also been conducted to investigate the relationship between parametric gain and parametric excitation at the onset of nonlinear dynamic response. (C) 2009 Elsevier B.V. All rights reserved.