Polarization Reconfigurable Horn Antenna Based On Spoof Surface Plasmon Polaritons

Abstract

In this paper, a polarization reconfigurable pyramid horn antenna is presented. A spoof surface plasmon polaritons (SSPP) waveguide is inserted into the pyramid horn antenna as a circular polarizer. Moreover, by rotating the circular polarizer, the horn antenna can radiate several different waves of left-hand circular polarization (LHCP), vertical polarization, and right-hand circular polarization (RHCP), thereby realizing reconfigurable polarization. The circular polarizer is a piece of dielectric substrate printed with periodic metallic grooves, which can propagate SSPP waves. There is a phase difference between the SSPP slow wave and the fast wave propagate by the waveguide. When the phase difference is +90° or -90°, the horn antenna will radiate circularly polarized (CP) waves. The proposed horn antenna with circular polarizer +45° or -45° rotated can radiate LHCP or RHCP waves. And the horn antenna radiates linearly polarized wave while the circular polarizer is horizontally inserted. The simulation results show that when the horn antenna radiates circularly polarized waves, it can achieve a 3-dB axial ratio (AR) bandwidth of 30% (from 8.45 to 11.5 GHz), and the reflection coefficients of the three polarizations are all less than -10 dB.