Realization of a new class of monolithic RF MEMS waveguide switches for millimeter-wave applications

A new category of monolithic RF MEMS waveguide switches for the millimeter-wave application is presented in this paper. The switches are based on monolithic integration of highly deflected RF MEMS actuators (cantilever beams) inside the waveguide channel. The waveguide structure and the MEMS components are simultaneously fabricated using a monolithic 8-mask fabrication process. It is shown that the actuators in the UP state virtually generate a conductive wall that can be used to reroute the signal and design various waveguide switch structures. When the actuators are pulled down, they coincide with the inner wall of the waveguide and are completely removed from the signal path. To prove the concept, a monolithic waveguide “Short” using the curled-up MEMS actuators is fabricated and the results are compared to a solid wall for the frequency band of 60 GHz-75 GHz. The idea is then generalized to show the feasibility of multiport structures such as C-type switch.