Compact effective surface plasmon polariton transmission line with undiminished bandwidth and enhanced field confinement

Abstract

In this work, we propose a compact effective surface plasmon polariton (CESPP) transmission line (TL) based on a structural dispersion-induced surface plasmon polaritons (SPPs) mode, which can enhance confinement while ensuring that the working bandwidth is not reduced. The dispersion relation of the CESPPs proposed in this article indicates that the shallower the groove, the stronger the confinement. Furthermore, the CESPPs may facilitate longitudinal miniaturization, since the configuration of the unit cell is simple. The coupling effect between two CESPP TLs has been well studied, revealing that excellent cross talk suppression can be achieved. The measurement results exhibit strong agreement with full-wave simulations, suggesting that the proposed CESPP TL holds significant potential for valuable applications in modern high-speed circuits.