RF MEMS Switch Technology

Commercial Applications Solid state and electromagnetic relay switches are being replaced by MEMS switches due to their lower costs and increased application performance. Some of the benefits of MEMS switches include low power consumption, long life cycle, linearity and increased switching speeds. Applications include highspeed digital channel switching in automated test equipment, filter bank switching in instrumentation and antenna switching in wireless communication. Radant MEMS is a company which specializes in the manufacture of 3-terminal RF MEMS microswitches, which employ a cantilever beam and are fabricated using an all-metal, surface micromachining process on high-resistivity silicon. The device operates in a hermetic environment, obtained through a wafer-bonding process, with an actuation gate voltage between 40 and 120 V. The wafer packaging process provides a direct connection to the customer’s system, reducing complexity and increasing reliability (exceeding 10 billion cold switched cycles); it is also more cost effective than ceramic or custom packaging [1]. Operational characteristics of the RF Switches include 5 μW power consumption at a switching rate of 1 kHz and an on-response time of approximately 5 μs (off-response time is much smaller) [2]. WiSpry is a competing RF MEMS manufacturer that is building its devices on active CMOS silicon structures to increase integration. This provides a roadmap from discrete RF capacitors to a fully integrated single-chip transceiver, and is performed in a standard CMOS process flow. This allows WiSpry to target high-volume mobile wireless applications with its superior ROI/cost points [3].