Development of a novel bidirectional electrothermal actuator and its application to RF MEMS switch

This paper presents the design and testing results of an electrothermally driven MEMS (microelectromechanical systems) actuator. Different from conventional uni-directional thermal actuators, this in-plane bi-directional electrothermal actuator is capable of producing displacements in two directions as a single device. The RF MEMS switch driven by this cascaded electrothermal actuator is also proposed. Due to this bidirectional actuator, the proposed switch can not only realize the OFF-state to ON-state shifting but also provide an additional deep OFF-state. At the deep OFF state, the isolation better than -30 dB can be achieved at the whole frequency range of 0 ~ 40 GHz.