S-shaped film actuator for low-voltage high-isolation MEMS metal contact switches

In this paper we present a novel metal-contact MEMS series switch based on a S-shaped film actuator. The switch consists of a flexible membrane rolling between a top and a bottom electrode. The s-shape of the film ensures that the membrane is always in close contact with both top and bottom electrodes, which results in a design with very low actuation voltages independent of the switching contact distance in the off-state. Thus, large switching areas are possible without decreased RF isolation. Furthermore, the design provides with active-opening capability making it less susceptible for stiction and self-actuation mechanisms. The switch is fabricated on two different substrates and finally assembled, leading to a near hermetic package integrated switch. The device was successfully fabricated and both the actuator and the RF performance of prototypes were characterized.