Rectangular Waveguide Fed Surface Wave Frequency Scanning Antenna Utilizing Wavevector Mismatch

In this letter, we propose a design of rectangular waveguide-fed surface-wave frequency-scanning antenna utilizing the principle of wavevector mismatch. First, the transition from a side-fed rectangular waveguide mode to spoof surface plasmon polariton (SSPP) is achieved. Then the SSPP propagating on the metal-dielectric interface is modulated through wavevector mismatching that induces the SSPP to spatial radiating wave conversion. Theoretical deduction proves the frequency scanning nature of the generated radiating beam. Phase gradient metasurface (PGM) is used to realize the wavevector engineering that causes artificial wavevector mismatch. Simulated and experimental results, agreeing well with each other, showed that the antenna can realize beam scanning from −8° to 11.6° across 6.8 to 7 GHz, with realized gain varying from 5 to 5.98 dBi.