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

Abstract

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.

Research and Analysis of MEMS Switches in Different Frequency Bands

“…A novel metal-contact MEMS switch with a bidirectional, electrothermal MEMS actuator designed by Zhu et al [ 50 ] achieved low insertion loss of 0.25 dB at 35 GHz and high isolation of 32.5 dB at 35 GHz and also realized low pull-down voltage of 0.3–0.5 V due to the high thermal conductivity and high thermal expansion coefficient of the actuator. Deng et al [ 51 ] achieved a low insertion loss of 0.3 dB at 35 GHz using a λg/4 sector open stub in a capacitive MEMS switch.…”