Wideband Frequency Scanning Spoof Surface Plasmon Polariton Planar Antenna Based on Transmissive Phase Gradient Metasurface

A novel design of spoof surface plasmon polariton (SSPP) planar antenna is proposed based on the wave vector modulation of transmissive phase gradient metasurface (TPGM). The antenna consists of TPGM placed a certain distance above SSPP guided wave structure, exhibiting the directional radiation property according to the generalized Snell's law. As an example, an SSPP planar antenna fed by rectangular waveguide is designed by using a wideband polarization rotating TPGM. Simulated and experimental results, agreeing well with each other, show that the planar antenna can achieve wideband frequency scanning from backward to forward. Compared to existing planar antennas, our SSPP planar antenna has advantages of wideband frequency scanning characteristic, higher efficiency, and higher degree of freedom for designing frequency scanning antenna, which would possibly open an avenue in designing conformal antennas and other new types of antennas.