Design and simulation of a novel RF MEMS switch anchored by springs three-levelly

Abstract

RF-MEMS switches can be categorized into two types based on their connection: metal-to-metal and capacitive. Metal-to-metal switches typically exhibit suboptimal performance compared to capacitive types, as they struggle to efficiently transmit high-frequency signals and power. Conversely, capacitive switches utilize a thin dielectric layer to prevent the beam from attaching to the transmission line in the off-state, facilitating easy release. This paper presents a novel design for a capacitive switch that effectively leverages RF MEMS technology, incorporating an innovative spring design. The proposed capacitive switch offers several advantages over its counterparts, including high isolation, low loss, low actuation voltage, and compact size and weight. Specifically tailored for Ka-band applications, the switch utilizes a spring mechanism to minimize the distance between the cantilever and the transmission line in CPW, thereby reducing the required activation voltage to just 1.5 V. A dielectric layer of SiO₂ with a thickness of 0.1 um is employed to enhance isolation and down-state capacitance. The proposed structural design not only enhances switch performance but also extends its lifespan by reducing stress levels, particularly in the spring component. The dynamic behavior and RF characteristics of the switch are analyzed using the COMSOL Multiphysics package and HFSS software, respectively, according to the findings, the switch demonstrates an S₁₁ value below − 8.75 dB and an S₂₁ value above − 1.06 dB across the frequency range of 1 to 40 GHz in the up-state configuration. In the down-state, the switch exhibits remarkable isolation in the Ka-band, with a resonance frequency of 19.53 GHz and an isolation value of − 43.3 dB.