Effect of Inertial Shock on RF MEMS Capacitive Switches Property in Low Vacuum

惯性冲击对低真空封装的RF MEMS电容开关性能的影响(英文)

The influence of outside inertial shock combined with RF signal voltages on the properties of a shunt capacitive MEMS switch encapsulated in a low vacuum environment is analyzed considering the damping of the air around the MEMS switch membrane. An analytical expression that approximately computes the displacement induced by outside shock is obtained. According to the expression, the minimum required mechanical stiffness constant of an MEMS switch beam in some maximum tolerated insertion loss condition and some external inertial shock environment or the insertion loss induced by external inertial shock can also be obtained. The influence is also illustrated with an RF MEMS capacitive switch example,which shows that outside environment factors have to be taken into account when designing RF MEMS capacitive switches working in low vacuum. While encapsulating RF MEMS switches in low vacuum diminishes the air damping and improves the switch speed and operation voltage,the performances of a switch is incident to being influenced by outside environment. This study is very useful for the optimized design of RF MEMS capacitive switches working in low vacuum.

分析了外界惯性冲击对低真空封装的旁路电容式RF MEMS开关性能的影响.得到了近似计算外界惯性冲击引起位移的解析式.在已知最大容许插入损耗和外部惯性冲击环境条件下,MEMS开关支撑梁的最小机械刚度常数以及外部惯性冲击引起的插入损耗可以根据该式得到.通过RF MEMS电容式开关实例,表明设计低真空封装的RF MEMS电容式开关时应考虑外部环境因素.可见,RF MEMS开关用低真空封装可以减小空气阻尼、改善开关速度和执行电压的同时,开关的性能却容易受外界环境因素的影响.该研究对低真空封装的RF MEMS电容式开关的优化设计很有意义.