Long Term Actuation Issues of Ohmic RF-MEMS Switches

Radio Frequency Micro-Electro-Mechanical Systems (RF-MEMS) are becoming more and more interesting for future wireless and wired RF applications [1]. Researchers’ attention is also moving to the possibility of using these devices as light and small redundancy switches in satellite applications. In such circuits, when a failure occurs in the main section, the redundancy switch must be able to disconnect it and connect the redundant circuit in a short time. Unfortunately, up to the last few years, the reliability of electrostatically actuated MEM switches has been mainly tested only in term of RF performances and cycling, neglecting other reliability issues. For example, in redundancy switch application, the main requirements are the switching certainty and time (in same applications less than 1s even after several years of working). In this work, beyond a traditional electrical characterization, we have tested the behaviour of two kind of MEMS switches under long actuation times, showing how the anchors geometry can impact on the reliability of such devices.