Design of High Isolation and Low Actuation Voltage Micro Cantilever RF-MEMS Switch for Enhanced Performance in mm-Wave Applications

One of the significant challenges in advancing RFMEMS switch technology is achieving low actuation voltage and high capacitance ratio, simultaneously. Reducing the structural spring constant and integrating Metal-Insulator-Metal (MIM) capacitors have been recognized as optimal strategies for lowering actuation voltage; while significantly improving the capacitance ratio in RF-MEMS switches. This study aims to design and development of an RF-MEMS shunt switch in which a cantilever microbeam with a MIM capacitor is integrated to enhance the RF performance in mm-wave frequency band. Simulation using COMSOL®, revealed that the actuation voltage, von mises stress, first resonance frequency mode, switch mass, and the spring constant of the designed switch is about <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2.3 ~\mathrm{V}, 5.16 \text{MPa}, 1352 ~\text{Hz}$</tex>, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$1.62 \mu ~\mathrm{g}$</tex>, and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.017 ~\mathrm{N}. \mathrm{m}^{-1}$</tex>, respectively; which are promising results. The switch's performance was evaluated across a wide frequency range from 1 to 100 GHz using ANSYS HFSS® simulation The simulation results indicate excellent radio frequency characteristics, i.e. isolation of -52 dB across the frequency range of 70 GHz to 75 GHz, with an insertion loss of -1 dB at 73 GHz and capacitance ratio of 142. These results highlight the favorable RF performance of the proposed switch, which is suitable for next-generation mm-wave applications.