Continuously tunable W-band phase shifter based on liquid crystals and MEMS technology

In this paper we present a continuously tunable phase shifter realized in MEMS technology. Varactors with liquid crystals as a tunable dielectric layer underneath gold bridges are utilized to build a loaded line phase shifter. Measurements show that the phase shifter has a differential phase shift of 92°, a figure of merit (FoM) of 42 YdB and an input matching of -19 dB at 76 GHz. The realized phase shifter can be used in combination with MEMS switches in order to build a 360° tunable reflection phase shifter.