Laterally-driven RF microswitch with high isolation

Most of MEMS microswitches that have been so far reported utilize a movable electrode moving vertically to a substrate. Especially, few researches have been made to apply a lateral motional MEMS microswitch to a high frequency range (above several GHz). Although the insertion loss is kept low in a wide range up to a high frequency, the isolation usually becomes worse with the increase of the signal frequency. We have improved the isolation in a high frequency by using lateral motion in mutually opposite directions. In addition, this lateral movement is effective to alleviate the adhesion of a contact area. We also consider about the feasibility of a silicon RF transmission line, which helps the process very easy because of keeping the overall structure simple. The microswitch under investigation has a simple structure and can be fabricated by the easy process. Its isolation is excellent as well as insertion loss even for a use in RF range. Rapid growing demands for more data traffic flow in mobile-phones and wireless LAN's tend to use a higher frequency band. Although the current microswitch has several improvements left, its excellent feature will make it more useful near the future.