Abstract

This doctorate thesis focuses on the analysis, design and characterization of Radio-Frequency (RF) Micro-Electro-Mechanical System (MEMS) switches for space applications. The work was inspired and supported by the European Space Agency (ESA) Contract No. ITT AO/1-5288/06/NL/GLC ?High Reliability Redundancy Switch?. The main purpose of the project is the design and realization of high-reliability RF MEMS switches for satellite payload redundancy networks. Up to now, the common satellite architecture implements redundancy networks by means of bulky devices. RF MEMS switches allow for extremely miniaturized networks along with outstanding performances in terms of losses, power consumption and linearity, not really achievable with solid state devices. As requirements for such an application, RF MEMS switches have to survive under extremely harsh environmental and operating conditions. In particular the device should handle continuous bias voltage (at least for 10 years), 5 W of RF input power and around 1000 actuation cycles without meaningful electrical and mechanical failure. The thesis proposes novel mechanical solutions to accomplish this task, exploiting active restoring mechanisms able to restore the previous status of switch in case of reversible failure. This work also provides a deep insight on the main reliability aspects of a RF MEMS device such as dielectric charging, contact degradation and power handling.