A Compacted 2.5-Dimensional Spoof Surface Plasmon Polaritons Transmission Line

In this letter, a compacted 2.5-dimensional (2.5-D) spoof surface plasmon polaritons (SSPP) transmission line (TL) is proposed and investigated. The 2.5-D SSPP structure consists of single-side corrugated grooves, metal patches and metallized via-holes. Compared with the 2-D planar SSPP with corrugated grooves structure, the proposed 2.5-D structure has smaller lateral dimension and more significant slow-wave (SW) features because the 2.5-D structure introduces extra dimension in the waveguide. The results show that the 2.5-D SSPP TL has an operating bandwidth from 0 to 20 GHz and the lateral width of the top layer can be reduced by 33% compared with the 2-D planar SSPP with single-side corrugated grooves.