MEMS based broadband phase shifters [articol]

Abstract

A phase shifter based on an array of MEMS is designed and then analyzed by computer simulation. It is shown that for a stable bridge position, the maximum ratio of the equivalent capacitance cannot exceed 1.2. For a microwave signal applied to the bridge, it is also shown that due to the very small time response of the MEMS, the equivalent capacitance depends on the DC voltage only. For this type of phase shifter, if the maximum operating frequency is much lower than the Bragg frequency, the phase shift varies linearly versus the frequency, so broadband applicatons such as pulse processing are possible.