An Ultra-Compact Surface Plasmon Transmission Line Based on Partially Grounded Coplanar Waveguide

In this article, a new spoof surface plasmon polariton (SSPP) developed from partially grounded coplanar waveguides (PGCPW) is proposed. By utilizing folded-strip-type DGS, the dispersion characteristics can be controlled. Based on the equivalent circuit analyses, it is found that the proposed PGCPW SSPP features lower asymptotic frequency than the conventional grounded coplanar waveguides (GCPW) SSPP with the same size occupation. As a result, the proposed PGCPW SSPP has a smaller size occupation to obtain the same asymptotic frequency. To illustrate the design principle, the proposed PGCPW SSPP TL is designed, fabricated, and tested. Results validate that the proposed PGCPW SSPP TL exhibits smaller unit cell size, transition size, and total size.