Experimental Investigation on the Exploitation of an Active Mechanism to Restore the Operability of Malfunctioning RF-MEMS Switches

RF-MEMS (MicroElectroMechanical-Systems for Radio Frequency applications) switches and components can enable the realization of high-performance and highly-reconfigurable blocks for a variety of applications in the field of telecommunications, spanning from mobile phones to scanning radar systems and satellite communications. Nevertheless, the exploitation of MEMS technology in the RF field is still limited by the relatively poor reliability of RF-MEMS devices and networks. In this work, we discuss the exploitation of an active mechanism that was recently presented by the authors, and capable of improving the robustness of RF-MEMS switches against stiction. The mechanism exploits the heat generated by an electric current driven through a high-resistivity PolySilicon serpentine, embedded within the switch structure, to recover the normal operability of the RF-MEMS relay, and is effective both against charge entrapped in the insulating layer as well as micro-welded spots due to large RF signals. The mechanism can be added with only minimal changes to a wide variety of already existing RF-MEMS switches and components topologies. In this paper we report the first experimental results showing a successful release of a stuck switch after the heater is activated. Moreover, we discuss proper activation methods of the proposed mechanism by performing FEM simulations in order to maximize the benefits of the PolySilicon heater operation without impairing the mechanical characteristic of the MEMS switch.