欧姆接触式RF MEMS开关设计与仿真

利用表面微加工工艺设计了一种双悬臂梁支撑的欧姆接触式MEMS开关,开关的材料为Au。通过对开关驱动电压的理论分析得出,悬臂梁的刚度越低,下拉电压就会越小;又因为刚度与悬臂梁厚度的三次方呈比例,所以,降低刚度最有效的办法就是减少梁的厚度。通过对开关的性能仿真发现:开关的闭合电压为44V;触点的接触力为22.45μN;谐振频率为25.5kHz。开关闭合时,触点接触后并非立即稳定,而是要弹跳数次后才趋于稳定,此现象增加了开关从闭合到稳定的时间。驱动电压为50,60 V时开关的弹跳时间分别为174.94,66.84μs,由此可见,通过适当增加电压可有效降低开关时间和由闭合到稳定的时间。

Design and simulation of ohmic contact-type RF MEMS switch

A double cantilever supported ohmic contact-type RF MEMS switch is designed by using surface micromachined process,the material is gold.As a result of the theoretical analysis on actuation voltage,the lower the stiffness of cantilever is,the smaller the pull-down voltage is.The most effective way to reduce stiffness is to decrease thickness of cantilever,because stiffness is proportional to cube of the cantilever thickness.Through property simulation,it＇s observed that the sealing voltage of the switch is 44 V,the contact force is 22.45 μN,the resonant frequency of which is 25.5 kHz.When the switch is closed,the contact may bounce a few times before making permanent contact,this bouncing increases the effective closing time of the switch.The switch bounce last for 174.94 μs at 50 V and 66.84 μs at 60 V respectively,which shows that through appropriately an increase voltage can effectively reduce switching time and time from shutting to level off.