Rotated Serpentine Spring Structure for Low Actuation Voltage CPW RF MEMS Switch

Background: RF MEMS switches can be used in radars, wireless systems, communication systems, phase shifters and switch matrices in order to achieve low power consumption, high isolation, small size and weight. Objective: This paper reports a low actuation voltage Capacitive Shunt RF MEMS Switch with two flexures, based on rotated serpentine spring concept. Method: The switch is designed on a CPW line with an impedance of 50 Ω. The dielectric is used is silicon nitrate with the thickness of 0.1 μm. Also, a cantilever beam switch and a switch with the serpentine spring structure based on meanders are simulated with the Comsol software and compared with the proposed switch. Conclusion: The results show actuation voltages of 15.89 V, 10 V and 7.755 V for the cantilever beam structure, serpentine spring structure and the proposed switch, respectively. RF scattering parameters are simulated by HFSS. Result: The results show that the return loss is -0.18 at 9.3GHz and the isolation is -37 dB at 9.3 GHz.