A Compact Single-Cantilever Multicontact RF-MEMS Switch With Enhanced Reliability

This letter presents a novel cantilever and electrode biasing design of a metal-contact radio frequency microelectro-mechanical systems (RF-MEMS) switch to integrate multiple contact points in a single cantilever to improve the reliability of the switch. In the design presented in this letter, multiple contact points are integrated in a single cantilever. The contact points are used to conduct RF current one by one until one point fails. To switch between the contact points, two actuator electrodes are placed under the cantilever and biased with different voltages and the touching point between the cantilever and bottom RF electrode are changed. The parasitic capacitance of the switch is kept to be the same with that of a single contact point RF-MEMS switch. The OFF-state isolation will not be worsen, while accumulation of the lifetime of each contact point can improve the overall lifetime of the switch. Without the need of shrinking the actuator to maintain small parasitics capacitance, the contact force is also not sacrificed when comparing to the case of putting several miniature switches together. The performance and reliability improvement of the switch are experimentally demonstrated. The insertion losses of the switch of different contact points are <1 dB, and the isolation is better than 10 dB up to 20 GHz.