Wide-Angle Frequency Scanning Metasurface Antenna Fed by Spoof Plasmonic Waveguide

We propose novel wide-angle frequency scanning metasurface antenna and antenna array fed by spoof plasmonic waveguide. The spoof plasmonic waveguide adopts the ultra-thin corrugated metallic strip which can support and propagate spoof surface plasmon polariton (SSPP) with high efficiency. By compensating the momentum difference between SSPP and free-space propagation modes via constant phase gradient, metasurface antenna can exhibit wide-angle and continuous radiation property according to the Generalized Snell's law. A prototype is designed, fabricated and measured, which consists of a wideband polarization rotating transmissive phase gradient metasurface (TPGM) placed a certain distance above spoof plasmonic waveguide. Such antenna works in a wideband range from 6.8 to 14.0 GHz, and the main beam can continuously scan from the forward direction to the backward direction with high efficiency. The measured results show that the scanning angle can reach 55°, which agree well with the simulated and theoretically calculated results. Furthermore, the proposed metasurface antenna can be combined easily as an antenna array with a simple feed network. Compared to single metasurface antenna, the antenna array exhibits the pencil-shaped directional radiation property, and the average gain of antenna array is obviously enhanced. The proposed frequency scanning metasurface antenna is of great value in the design of conformal antenna and the large aperture antenna array, especially on curved faces.