An Approach to Near Zero Power Bi-Stable Driving With a Simple Pulse Signal for RF MEMS Switch

Abstract

This paper reports a novel bi-stable structure for a radio frequency micro-electro-mechanical system (RF MEMS) switch. The structure is activated by an in-plane electrostatic actuator and adopts the Inertial Generated Timing Sequence (IGTS) method to latch, allowing the switch to turn on and off with a simple pulse signal. This design eliminates the need for a complex external control circuit and enables the switch to maintain the ON state at zero power consumption. Furthermore, the electrode shape is designed to reduce the driving voltage, thereby lowering the power consumption of the boost circuit. To test and verify the functionality of the bi-stable mechanism, a coplanar waveguide (CPW), which is separated from the actuation structure to reduce interference between the DC drive signal and the RF transmitted signal, is employed. Fabricated using a silicon-on-glass process with two lithographic masks, the RF MEMS switch achieves bi-stability with a single pulse signal of 18V for latching and 14V for unlatching. The measured insertion loss and isolation at 6 GHz are −0.28 dB and −36.68 dB, respectively. This switch exhibits low pull-in voltage, low power consumption, and simple control, holding potential for future RF systems tailored to wireless applications with an emphasis on low power consumption and system simplicity. [2024-0008]