14 GHz MEMS 4-bit phase shifter on silicon

In this abstract we describe the work in progress on a 4-bit coplanar waveguide (CPW) MEMS phase shifter simulated, fabricated, and measured at 14 GHz on 400 μm high-resistivity silicon (ε_r=11.7). Simulated results using a full wave simulator predict a return loss better than 19 dB and isolation better than -0.1 dB for a one bit phase shifter using perfectly conducting lines. Measurement results for single MEMS switches have shown -22 dB return loss and -0.095 dB isolation in the UP (not activated) state and -0.83 dB return loss and -14.5 dB isolation in the DOWN (activated) state. It has also been shown that the single bit phase shifters exhibit accurate phase shifts, but higher than expected loss.