电信系统中的硅微机械滤波器结构鲁棒设计

基于2振动自由度的静电梳驱动折叠梁微机械滤波器振动模型,利用结构鲁棒设计思想,在指定耦合梁宽度等于振子折叠梁宽度的前提下,推导出了两个固有频率对微梁宽度工艺误差的灵敏度模型,得到了对工艺误差不敏感的梳状振子应满足的几何条件,将现有参考文献中仅适用于单个振动自由度微谐振器的结论推广到了多振动自由度微机械滤波系统。并以正方形作为振子基本形状,推导出了折叠梁宽度与补偿孔壁厚、补偿孔数量的重要关系。最后,给出了设计实例。所提出的方法对于其他类型的多自由度微机械振动系统设计也有重要的参考意义。

ROBUST STRUCTURE DESIGN FOR MEMS FILTRERS IN TELECOMMUNICATION

The frequency characteristics of a two-degrees laterally vibrating MEMS filter are analyzed. With the fabrication error on the sidewall of fold beam being considered, the first sensitivity functions of two natural frequency to the fabrication error are derived. A simple relationship between the proof mass and perimeter, and the beam width is developed. Some important conclusions between the width of fold beam, the width of compensatory-hole wall and the number of compensatory-hole are presented for the filter design, and a robust design scheme is developed. Design examples are given finally. The results and principles presented can be used to design and analyze other multiple degrees of freedom MEMS devices.