A novel MEMS distributed phase shifter for D-band application

A novel MEMS distributed phase shifter for D-band application is presented, in which the open-ended CPW lines in series with MEMS bridge provides exactly capacitance in order to optimize the instability caused by the MEMS bridge movement and meet the required loaded capacitance. The planar structure of open-ended CPW lines could enhance the reliability and avoid performance degradation because of process error. The MEMS bridge anchored to open-ended CPW offers a so flexible anchor position that it results in a low actuation voltage and also reduce the design conditionality between RF characteristics and mechanical characteristics such as pull-in voltage and response time. The designed D-band 5-bit distributed phase shifter exhibits an average insertion loss of −4.15dB for 32 states at 140GHz, and worst case of −5.88 dB throughout D-band, while the return loss is better than −15dB in D-band. The pull-down voltage of the MEMS bridges is lower than 36V and could be further reduced.