A multiband RF MEMS switch with low insertion loss and CMOS-compatible pull-in voltage

In this paper, we present a novel design of a shunt capacitive, multiband, micro-machined RF switch. The concept of float metal is utilized to reduce the overlap area and therefore the capacitance in the upstate of the device. A full electromechanical model that accounts for residual stress effects is developed to predict the losses, performance, and pull-in voltage of the RF MEMS switch. The new design shows an insertion loss of 0.08 dB, an isolation loss of 85 dB up to 25 GHz, and a pull-in voltage of 3.5V. The low pull-in voltage makes this switch suitable for integration with RF CMOS transceivers. A seamless RF MEMS modelling and verification methodology using state-of-the-art finite-element-method (FEM) tools is developed and used to analyze the switch in both the electromechanical and RF domains.