基于谐振原理的RF MEMS滤波器的研制

采用与IC工艺兼容的硅表面MEMS加工技术,以碳化硅材料作为结构材料,研制出一种新型的基于谐振原理工作的RF MEMS滤波器。详细介绍了器件的工作原理、制备方法、测试技术和结果,并对测试结果做出分析。该RF MEMS滤波器由弹性耦合梁连接两个结构尺寸和谐振频率完全相同的MEMS双端固支梁谐振器构成,MEMS谐振器的结构决定了滤波器的中心频率,弹性耦合梁的刚度决定了滤波器的带宽。在大气环境下测试器件的频响特性,得到中心工作频率为41.5MHz,带宽为3.5MHz,品质因数Q为11.8。     

SOI MEMS陀螺的制造和测试

This paper presents an SOI（silicon on insulator） MEMS（micro-electro-mechanical systems） vibratory gyroscope that was fabricated using bulk micromachining processes.In the gyroscope architecture,a frame structure that nests the proof mass is used to decouple the drive motion and sense motion.This approach ensures that the drive motion is well aligned with the designed drive axis,and minimizes the actual drive motion component along the sense detection axis.The thickness of the structural layer of the device is 100μm,which induces a high elastic stiffness in the thickness direction,so it can suppress the high-order out-of-plane resonant modes to reduce deviation.In addition,the dynamics of the gyroscope indicate that higher driving mass brings about higher sensing displacements.The thick structural layer can improve the output of the device by offering a sufficient mass weight and large sensing capacitance.The preliminary test results of the vacuum packaged device under atmospheric pressure will be provided.The scale factor is 1.316×10^-4 V/（deg/s）,the scale factor nonlinearity and asymmetry are 1.87%and 0.36%,the zero-rate offset is 7.74×10^-4 V,and the zero-rate stability is 404 deg/h,respectively.     

使用差分方法消除微机电滤波器的穿通以及对由此引入的陷波现象的分析

This paper presents and analyzes a notch observed in MEMS(micro electric mechanical system) filter characterization using the difference method.The difference method takes advantage of the cancellation of parasitic feed-through,which could potentially obscure the relatively small motional signal and lead to failure in characterization of the MEMS components.In this paper,typical clamped-clamped beam MEMS filters are fabricated and characterized with the difference method.Using the difference method a better performance is obtained but a notch is induced as a potential problem.Analysis is performed and reveals the mismatch of the two differential excitation signals in measurement circuit contributes to the notch.The relevant circuit design rule is also proposed to avoid the notch in the difference method.