Analysis and design of high-performance liquid crystal phase shifter based on nanowire filled membrane and spoof surface plasmon polaritons

In this paper, the design and analysis methods of Liquid crylstal phase shifter (LCPS) with high performance based on nanowire filled membrane (NaM) and spoof surface plasmon polariton (SSPP) are proposed. The equivalent transmission line model and distributed circuit parameters of a NaM-LCPS are constructed and compared with those of a conventional microstrip line liquid crystal phase shifter (ML-LCPS) to reveal the causes of the high figure of merit (FoM) of the NaM-LCPS. Building upon above analyses, an idea of combination of SSPP and NaM-LCPS is proposed to improve the NaM-LCPS's performance. Simulation results show that the NaM-SSPP-LCPS reaches an outstanding FoM of 123.5°/dB and a per wavelength phase shift of 377.5°/λ0, however, NaM-LCPS only has a FoM of 98.9°/dB and a phase shift of 241°/λ0 per wavelength, which increases by 24.87 % and 56.64 % compared to the NaM-LCPS, respectively, implying higher efficiency and more compact physical size.