High FoM liquid crystal based microstrip phase shifter for phased array antennas

An electrically tunable microstrip phase shifter for applications of phased array antennas is designed based on nematic liquid crystal material. The experimental results show a tunable differential phase shift up to 270 at 10 GHz, and the insertion loss is less than 9 dB at 1-10 GHz range. By optimizing both of the liquid crystal tuning efficiency and overall loss, an average figure-of-merit (FoM) 40°/dB has been achieved in frequencies 1-10 GHz.