电容式射频微机电系统开关损耗机制

插入损耗是射频微机电系统 (RF MEMS) 开关的关键性能指标之一。电容式RF MEMS开关是一种适合高频应用的开关器件，对其损耗机制进行了研究。电容式RF MEMS开关的射频损耗主要包括四部分:信号线的导体损耗、衬底损耗、辐射损耗以及MEMS桥损耗。对电容式RF MEMS开关建立了损耗模型并进行了数值计算，同时在HFSS有限元软件中进行了电磁仿真，数值计算结果和有限元仿真结果较好的吻合。此外，对影响电容式RF MEMS开关插入损耗的因素进行了分析，结果表明，高阻抗的衬底、200 m左右的导体宽度、较小的导体厚度以及较小的up态电容能够降低开关的插入损耗，提高开关的射频性能。

Loss mechanisms of radio frequency micro-electro-mechanical systems capacitive switches

Insertion loss is an important performance indicator for radio frequency micro-electro-mechanical systems (RF MEMS) switches. The RF MEMS capacitive switch is a kind of RF MEMS switch which is suitable for high frequency use. Its loss mechanisms are investigated in this paper. Four main parts contribute to the RF MEMS capacitive switchs insertion loss: conductor loss of the signal lines, substrate loss, radiation loss, and MEMS bridge loss. Loss models are built and calculated, and numerical calculation results agree well with simulation results. In addition, influence factors of insertion loss are analyzed, and results show that high resistivity substrate, conductor width around 200 m, smaller conductor thickness and smaller up-state capacitance can help lower the insertion loss.