Spatial Multi-Polarized Leaky-Wave Antenna Based on Spoof Surface Plasmon Polaritons

A leaky-wave antenna (LWA) is proposed on the basis of an ultrathin spoof surface plasmonic (SSP) waveguide, which can convert SSP waves into spatial multi-polarized radiation waves. The SSP waveguide is composed of a metallic strip line with periodic unit cells, and each unit consists of two orthogonally beveled slots. The feature of the single-conductor SSP waveguide determines that the leaky-wave radiation pattern is omnidirectional in the azimuth direction around LWA. Due to the design of orthogonally beveled slots, different polarized radiations can be achieved along the azimuth direction. Simulation results show that left-handed circularly polarized (LHCP), right-handed circularly polarized (RHCP), and linearly polarized (LP) radiations are achieved in different azimuth directions simultaneously, which are further validated by the experimental measurement. We also demonstrate a purely single polarized radiation by placing a metal reflector close to LWA, and the polarization is reconfigurable among LHCP, RHCP, and LP by mechanically rotating LWA.