Dynamics of MEMS resonators under superharmonic and subharmonic excitations
Dynamics of MEMS resonators under superharmonic and subharmonic excitations
复制标题
DOI：
10.1088/0960-1317/15/10/008
复制
发表时间：
2005-10-01
影响因子：
2.3
通讯作者：
Younis, MI
中科院分区：
文献类型：
--
作者：
Nayfeh, AH;Younis, MI
对电驱动微梁在二次共振激励下的动力学行为进行了分析和仿真。所提出的模型和方法，使进行小或大的运动的微梁的瞬态和稳态动力学的模拟。微梁由直流静电力和交流谐波力激励，其频率调谐到接近其基本自然频率的两倍（阶次谐波激励的一半）或其基本自然频率的一半（阶次谐波激励的二）。在超谐波激励的情况下，我们提出的结果表明，不同的直流偏置，阻尼和交流激励振幅的频率响应曲线的效果。在次谐波激励的情况下，我们表明，一旦次谐波共振被激活，所有的频率响应曲线达到吸合，无论大小的交流强迫。我们得出结论，在这种情况下，品质因数对频率响应的影响有限。这一结果和频率响应曲线具有非常陡峭的通带到阻带过渡的事实使得直流电压和二分之一阶次谐波激励的组合成为设计改进的高灵敏度RF MEMS滤波器的有希望的候选者。对于这两种激励方法，我们表明，动态吸合不稳定性可以发生在一个电负载远低于纯直流电压和相同的数量级的情况下的主共振激励。
We present an analysis and simulations for the dynamics of electrically actuated microbeams under secondary resonance excitations. The presented model and methodology enable simulation of the transient and steady-state dynamics of microbeams undergoing small or large motions. The microbeams are excited by a dc electrostatic force and an ac harmonic force with a frequency tuned near twice their fundamental natural frequencies (subharmonic excitation of order one-half) or half their fundamental natural frequencies (superharmonic excitation of order two). In the case of superharmonic excitation, we present results showing the effect of varying the dc bias, the damping and the ac excitation amplitude on the frequency-response curves. In the case of subharmonic excitation, we show that, once the subharmonic resonance is activated, all frequency-response curves reach pull-in, regardless of the magnitude of the ac forcing. We conclude that the quality factor has a limited influence on the frequency response in this case. This result and the fact that the frequency-response curves have very steep passband-to-stopband transitions make the combination of a dc voltage and a subharmonic excitation of order one-half a promising candidate for designing improved high-sensitive RF MEMS filters. For both excitation methods, we show that the dynamic pull-in instability can occur at an electric load much lower than a purely dc voltage and of the same order of magnitude as that in the case of primary-resonance excitation.