Novel mode-matched MEMS gyroscope with high capacity to tune frequency and Q-factor

本文介绍了一种新型的三质量谐振器（TMR）和一种具有多个检测质量的双轴对称谐振器，用于提高MEMS谐振器的刚度灵敏度和调谐能力。反相（ωanti）和同相（ωin）模式的频率分别对悬架和内部刚度有很强的依赖性。因此，频率差可以通过悬架刚度或内部刚度进行静电调谐。通过减小内刚度可以很大程度上调节振幅比，这会使与锚损失或挤压油膜阻尼相关的Q因子发生显著变化，而频率ωanti的变化可以忽略不计。当通过降低两个主要检测质量块的悬挂刚度来调谐频率ωanti时，仅观察到模态形状（即振幅比）的轻微变化，从而引起对Q因子的微小调整。因此，频率ω_（anti）和Q值可以在相互影响较小的情况下独立调谐。两个动态等效的检测质量提供了一个平衡的动态系统，四个额外的小质量之间的实施，这可以调整两个反相模式的Q因子独立的频率影响很小。频率主要受悬架刚度的影响，而Q因子则通过两个平衡质量块和小质量块之间的模态耦合强烈地依赖于挤压油膜阻尼。

This research introduces a novel triple mass resonator (TMR) and a two-axis symmetric resonator with multiple proof masses for improving stiffness sensitivity and tuning capability of MEMS res- onators. The frequencies of the anti-phase (ωanti) and in-phase (ωin) modes have a strong dependency on the suspension and inner stiffness, respectively. Therefore the frequency difference can be electro- statically tuned by either suspension stiffness nor inner stiffness. The amplitude ratio can be adjusted largely by decreasing the inner stiffness, which brings a significant change in Q-factor related to anchor loss or squeeze film damping, while a negligible shift in frequency ωanti. When the frequency ωanti is tuned by decreasing suspension stiffness of two main proof masses, only a slight change in the mode shape, i.e. the amplitude ratio, is observed causing a minor adjustment to Q-factor. Therefore the frequency ωanti and Q-factor can be tuned independently under a little mutual influence.A two-axis symmetric tuning fork resonator based on TMR technique is applied for QFM/RIG. Two dynamically equivalent proof masses provide a balance dynamic system and four extra-small masses is implemented in between them, which could tune the Q-factor of two anti-phase modes independently with small effect on the frequency. Frequency is mainly affected by suspension stiffness and Q-factor is strongly dependent on the squeeze film damping through the mode coupling between two balanced masses and small masses.