Feasibility of Additively Manufactured Tunable Liquid Crystal Loaded Dielectric Waveguides

This letter investigates the feasibility of the combination of additive manufacturing and liquid crystal (LC) loaded dielectric waveguides (DWGs) at ${W}$ -band (75–110 GHz). The waveguide is extruded such that it has a cavity in its center, used for LC hosting. Reproducible cross sections are achieved along the DWG and high agreement between differential phase shift and figure-of-merit (FoM) is obtained when the DWG is biased electrically or magnetically. Deembedding the structure shows attenuation constants between 0.12 and 0.33 dB/cm which lead to a high FoM in the range of 100°/dB to 160°/dB. According to simulations, higher values are obtainable if larger LC cavities are realized.