RF performance of rec-BCPW and arc-BCPW DMTL millimeter-wave phase shifters

In this paper, novel RF distributed MEMS transmission line (DMTL) phase shifters based on rectangular and arched bridge-like coplanar waveguides (rec-BCPW and arc-BCPW) structure are proposed and the comparison of their configuration and RF performance is also presented. A CST software is used for the modeling, simulation and optimization from 30 to 40GHz. Simulation and optimization results show that both the rec-BCPW and arc-BCPW phase shifters make an improvement on the conventional phase shifter in S parameters. However, at “down” state of 35GHz resonant frequency, the return loss (S11)of arc-BPCW phase shifter is 3dB less than that of rec-BPCW, while at “up” state, the return loss of arc-BCPW gets 15dB higher. For phase shift, arc-BCPW has an average gain of 30° from 30GHz to 40GHz than rec-BCPW. As of configuration, arc-BCPW suffers a larger size for a higher arched bridge and a wider MEMS bridge space. As the common feature of BCPW, interference among the adjacent components can be decreased. The fabrication and measure of rec-BCPW and arc-BCPW phase shifters will be carry out in subsequent research.