Rugged and reliable ohmic MEMS switches

MEMS are becoming important building blocks for a variety of military and commercial applications including phase shifters, electronically scanned antennas, switched filters, Automatic Test Equipment, instrumentation, cell phones and smart antennas. Low power consumption, large ratio of off-impedance to on-impedance, extreme linearity and the ability to be integrated with other electronics, make MEMS switches attractive. Wafer Level Packaging and contact metallurgy have contributed to the steady progress that has been made in improving RF MEMS switch reliability during the past five years. Extensive lifetime and RF testing has been conducted on an electrostatically actuated broadband ohmic microswitch under the auspices of the DARPA HERMIT program. Final testing led to a median cycle to failure greater than 1 trillion cycles with the longest recorded lifetimes exceeding 1.5 trillion switch cycles before the test was halted after 30 continuous months. Testing was also conducted on a high-power MEMS switch that demonstrated greater than 200 billion switch cycles with 10W of cold-switched RF power at X-Band. Finally, a series of environmental tests including temperature cycling, humidity testing, and mechanical shock and vibration were successfully conducted per MIL-STD-883E.