RF characteristics investigation of MEMS phase shifter with CPW discontinuities

The operating principle of the RF MEMS phase shifter is described. Two improved design approaches based on the CPW discontinuities to decrease the return loss are proposed. By using network theory and CST microwave studio simulation tool, the proposed RF MEMS phase shifters are modeled. Simulation results for the two designs are compared and discussed based on the analysis. Simulation results show that less than -10 dB return loss and more than -2 dB insertion loss is achieved for over 1 GHz bandwidth range for the proposed models. At least 6 dB return loss decrease is realized compared with the conventional MEMS phase shifter design methods.