Designing a Novel RF MEMS SWITCH for Broadband Power Applications

The design of a new type of RF MEMS "toggle" switch for broadband power applications is described. The switching element consists of a cantilever, which is fixed by a torsion spring to the outer conductor of the coplanar line. Two electrodes below the cantilever are used to toggle the switch between open and closed position. The switching voltages are aproximately 10V. The single switch exhibits low loss (<0.4dB for DC-35GHz) with good isolation (>15dB for DC-30GHz). Based on this single switch a SPDT switch has been designed which consists of two toggle switches and two capacitive shunt switches. The combination of these two switch types makes it possible to achieve an excellent performance of 50 dB isolation and less than 0.3 dB insertion loss in a frequency range up to 30 GHz.