低驱动电压电容式RF MEMS开关结构设计优化  

Mechanical Topology Optimization for Low Threshold Voltage Capacitive RF MEMS Switches

作　　者：高杨[1,2] 刘佳[3] 白竹川[4] 刘婷婷[3] 陈营端[3] 

机构地区：[1]中国工程物理研究院电子工程研究所,四川绵阳621900 [2]重庆大学光电技术及系统教育部重点实验室,重庆400044 [3]西南科技大学信息工程学院,四川绵阳621010 [4]西南科技大学制造科学与工程学院,四川绵阳621010

出　　处：《微纳电子技术》2009年第3期160-165,共6页Micronanoelectronic Technology

基　　金：中国工程物理研究院科技发展基金重点课题(2008A0403016);教育部访问学者基金资助项目

摘　　要：RFMEMS开关将成为微波、高频信号控制的关键器件。针对其驱动电压过高,不能满足现代通信系统低电压的要求,推导了电容式RFMEMS开关驱动电压的理论公式;基于降低开关柔顺结构的弹性系数、驱动电极上极板与可变电容上极板分离的思路,优化设计了三种具有不同的连接梁和支撑梁结构形式的开关微桥柔顺结构。第一种结构为驱动电极板和电容上极板之间以双直梁连接;第二种结构以一组弹性折叠梁代替结构一中的双直梁;第三种结构是在结构二的基础上,改变了起支撑作用的弹性折叠梁的方向。使用MEMS CAD软件CoventorWare对开关结构进行了机电耦合仿真,仿真结果表明开关的驱动电压小于3V。A RF MEMS switch will be the key element in the field of the microwave and mm-wave signal control. A challenge of the practicability is that the threshold voltage is too high to meet modern low voltage communication systems. Formula for the threshold voltage of the capacitive RF MEMS was deduced. Based on the idea to reduce the elasticity coefficient of the compliant mechanism and to separate the upper pull-down capacitor plate from the upper variable capacitor plate, three optimized switch compliant mechanism topologies were designed with different link-beam and suspend-beam assemblies. In the first optimized topology, two straight beams were used to connect the separated upper pull-down capacitor plate and upper variable capacitor plate. In the second one, folded beams were used to replace those straight beams in the first one. In the third one, the directions of the folded beams suspending the bridges were perpendicular to those in the previous two cases. CoventorWare, a MEMS CAD software, was utilized to simulate the electro-mechanical characteristics. Simulation results demonstrate that the threshold voltages of the switches are lower than 3 V.

关 键 词：微电子机械系统 射频微电子机械系统 开关 机电耦合Ware软件 

分 类 号：TH703[机械工程—仪器科学与技术] TH702[机械工程—精密仪器及机械]