A low-voltage high contact force RF-MEMS switch

This paper describes a novel structure for an electro-static actuated RF-MEMS metal-contact switch which achieves low-voltage actuations. Using a cantilever and placing a pull-down electrode outside the contact dimples, the actuation voltage can be reduced greatly while keeping a high contact force and restoration force. The simulation results show that the novel design operates around 20 V and produces a contact force of >200 μN per contact, and a restoration force of >115 μN per contact. The measured actuation voltage is 20-30 V which is higher than the designed value, and is thought to be caused by stress induced deflection. The measured RF isolation is 29 dB (Cu=28 fF) and the measured insertion loss is 0.2 dB (Rs=2.1 Ω) at 2 GHz.