Novel design of MEMS ohmic RF switch with low voltage actuation

In this paper, we propose the design of an ohmic contact RF microswitch with low voltage actuation, where the upper and lower microplates are displaceable. We develop a mathematical model for the RF microswitch made up of two electrostatically-actuated microplates; each microplate is attached to the end of a microcantilever. We assume that the microbeam is flexible, the microplates are rigid bodies and the electrostatic force is nonlinear function of the displacement and voltage applied between the microplates. We formulate the static and eigenvalue problems associated with the proposed microsystem. We show that the resulting static pull-in voltage and switching time are reduced by 30 and 45%, respectively, as compared to those associated with a RF microswitch formed of a single microbeam-microplate system. We also show that, unlike the second and higher frequencies, a selected range of applied DC voltages, affects significantly the first frequency.