Kind of high directivity scanning radiation based on subwavelength periodic metal structure

A new kind of leaky wave antenna based on low-frequency surface plasmon polaritons (SPPs) is proposed, which is constructed by periodic metallic blocks with an open slot on the top. Numerical analysis shows that by introducing the open slot on the metallic blocks, there will appear extra spoof SPPs modes in the band gap of metallic solid blocks. The dispersion curve of such spoof SPPs modes passes through the light line and enters into the radiation region, and consequently it can generate a frequency steering pencil-like radiation. Experimental verification agrees with the theory.