Managing 60 GHz Field Peaking of an Liquid Crystal Enclosed Coplanar Waveguide by Core Edge Shaping

This work numerically investigates a novel insertion loss mitigation strategy by shaping the core line's edge profile in hexagonal, trapezoidal, and rounded configurations for an enclosed coplanar waveguide filled with liquid crystals as tunable dielectrics. As compared with a right-angled core line, full-wave simulation results show that the optimal hexagonal edge profile with a chopping angle of 7.12° and offset distance of 17μm reduces the insertion loss by 0.57 dB at 60 GHz for a 0-π phase shifter, while trapezoidal and rounded core edges degrade the forward transmission by 2.59 dB and 0.26 dB, respectively.