Development and Evaluation of RF MEMS Switch Utilizing Bimorph Actuator Technology for Enhanced Ohmic Performance

In this work, the design and operation of a bimorph actuator-based ohmic RF MEMS switch analyzed using Finite Element Method tool. The resultant out–of-plane deflection of the bimorph actuator facilitates both electrical and thermal isolation for the proposed switch. The isolation of the ‘switching platform’ is achieved through electrothermal actuation. The operation of the device is defined in such a way that during the closed state, the switching platform comes in contact with the RF signal path. Otherwise, when not in contact, the RF switch will be isolated from the switching platform, which is the normal open state. Hence the proposed design assures the lowest power consumption. In this design, the bimorph actuator is implemented using a pair of materials namely Titanium (Ti) and Gold (Au). The improved heat capacity and coefficient of thermal expansion of Ti material compared with Au, provides better out-of-plane deflection during actuation. The performance of the device is analyzed for a range of actuation potentials and an optimum deflection of 420μm is achieved at 3.3V.