Compact design of complementary spoof surface plasmon polaritons transmission line

Novel miniaturized design of complementary spoof surface plasmon polaritons transmission line (CSSPP-TL) is proposed in microwave frequency. It is composed of complementary corrugated metallic strip and interdigital structures (ISs). The proposed CSSPP-TL features small linewidth, flexible dispersion control, and highly selective filtering performance. Simulated results show that the proposed CSSPP-TL has low insertion loss and high transmission efficiency. The dispersion properties of CSSPP with interdigital structures are studied. The cutoff frequency of the design is decreased by 50%, compared to that of conventional CSSPP transmission line, which indicate that, by introducing extra ISs, a smaller propagating wavelength and a tighter electric field confinement is realized, ensuring reliable applications in miniaturized plasmonic devices and low-interference SPPs circuits.