Design of a 3-state Unit Cell for DMTL Phase Shifters

A novel 3-state unit cell for distributed MEMS transmission line (DMTL) phase shifters is designed and simulated in this paper. The proposed structure consists of a coplanar waveguide transmission line, a MEMS and two-pair metal-air-metal bridges. The bridges are actuated respectively in three different modes which produce three different phase shifts. The structure is simulated using HFSS software. Based on the simulation results, the return loss in all 3 states is better than -10dB and the phase shift is in good agreement with ideal values. The designed unit cell is very suitable for 5-bit and 6-bit DMTL phase shifters.