Liquid crystal based low-loss phase shifter for W-band frequencies

A novel liquid crystal (LC) based hollow waveguide phase shifter with an LC section of 14.6 mm is presented , operating at 80-110 GHz. As a proof-of-concept, the phase shifter is biased by using permanent magnets, which results in a differential phase shift of 307°=318° and an insertion loss of 2.1-2.7 dB in the desired frequency range of 99- 105 GHz. Hence, a phase shifter figure of merit of 118°-148°/dB is determined, which are to the authors´ knowledge the highest values in this frequency range for passive phase shifters.