Ultra-thin and polarization-independent phase gradient metasurface for high-efficiency spoof surface-plasmon-polariton coupling

Abstract

In this study, a polarization-independent phase-gradient metasurface (PGM) for spoof surface-plasmon-polariton (SPP) coupling is proposed and investigated using theoretical simulations and experiments. The designed PGM is composed of a periodic array, which consists of a dielectric spacer sandwiched between a metallic petal structure and metal film. The numerical results indicate that, when the composite surface wave vector is greater than that of the incident wave, an arbitrarily incident linearly polarized electromagnetic wave can be efficiently coupled to yield a spoof SPP. The results obtained from both simulation and experiments are consistent with theoretical predictions. The PGM spoof SPP coupler design is polarization independent and highly efficient at the X-band.