A V-band CPS distributed analog MEMS phase shifter

In this work, a new V-band CPS analog distributed MEMS phase shifter has been developed. Since this phase shifter is based on the balanced CPS lines, no extra mode transition structure is required for integration with the balanced circuits using CPS or slot line as well as for packaging in the waveguides. MEMS bridges over the coplanar strip lines are used to control the mutual capacitance between two CPS strip lines, consequently the phase response of the capacitively loaded CPS line. The fabricated phase shifter showed 55/spl deg//dB at 40 GHz and 74/spl deg//dB at 60 GHz. The return loss is better than 8 dB over a wide frequency range from 1 to 70 GHz. For measurement with CPW-based on-wafer system, a new ultra wideband CPW-to-CPS transition has also been developed, and showed a low insertion loss less than 1.9 dB from DC to 110 GHz.