A Proposed π-Structure RF MEMS Switch for Wide Bandwidth and High Isolation Applications

This paper presents a π-structure for RF MEMS switch based on numerical experimentation using 3D EM simulator. It has very low insertion and return losses in the ON-state and very high isolation in the OFF-state, over a wide bandwidth. It exhibits a minimum isolation of 50 dB, in the frequency range from dc to 50 GHz, and of 30 dB in the frequency range from 50 to 60 GHz. The insertion loss ranges from 0.2 to 2 dB and a minimum of 25 dB return loss up to 50 GHz. To the best of the authors’ knowledge, this is the highest isolation reported so far for RF switches over such a wide frequency band. The switch is actuated by a DC voltage of 30 to 50 volt. Both shunt capacitive and series resistive switch fabrication processes on the wafer are compatible.