Passive Phase Shifter for W-Band Applications using Liquid Crystals

In this paper a ridged waveguide phase shifter at W-band frequencies is presented. A taper matches the ridged waveguide phase shifter to the rectangular waveguide feed. Three different liquid crystals (LC) are used: a quasi-standard LC K15, a highly anisotropic mixture MDA-03-2844, and a dual-frequency switching LC MDA-05-1132, all synthesized by Merck KgaA. The return loss of the phase shifter device is always below -10dB in the whole W-band. The maximum achievable figure-of-merit of these materials is 78deg/dB at 108 GHz