Compact Spoof Surface Plasmon Polariton Waveguides With Simple Configurations and Good Performance

Two compact spoof surface plasmon polariton (SSPP) waveguides are proposed with simple configurations and good performance. Compared with the conventional SSPP structure having same asymptotic frequency, a new design of the tilted-stub structure occupies less transversal space. Moreover, this design can be applied in the SSPP cases with small period values, which will facilitate the longitudinal miniaturization. Then, an improved SSPP structure is constructed to realize the transversal size reduction of 58% compared with the conventional corrugated SSPP waveguide. For these two proposed waveguides, smooth transitions from microstrip lines to SSPPs are designed with seamless connection. Two experimental prototypes have been fabricated, whose measurements are in good agreement with the simulated ones. The proposed designs will have significant potentials for the miniaturization of plasmonic devices and circuits.