A DMTL phase shifter using insulation layer and saw-shaped CPW

Abstract

The phase shift features of the RF MEMS phase shifter are described. The approach of adding an insulation layer below the RF MEMS bridge to increase phase shift and improve reliability is proposed, in addition, the saw-shaped CPW is used to decrease the return loss introduced by the insulation layer. By using network theory and CST microwave studio simulation tool, the proposed RF MEMS phase shifter is modeled. Simulation results show that the proposed model has the return loss less than -10dB and the insertion loss more than -2dB in 2GHz bandwidth range. For one RF MEMS switch-type bridge, as high as 22.5 degrees phase shift is realized.