Spoof surface plasmon polaritons of complementary periodic units with negative group velocity effect

Abstract

Periodically patterned conductor surfaces can transmit electromagnetic modes similar to surface plasmon polaritons, which are called spoof surface plasmon polaritons (SSPPs). In this paper, noncoplanar dentate complementary structure units are proposed. In this case, the fundamental SSPP is split into two modes, of which the mode in the high‐frequency side exhibits negative group velocity (NGV) near the cutoff frequency. The dispersion characteristics of NGV modes can be controlled by manipulating the symmetry of the complementary structure. It is confirmed that the actual transmission wave in the SSPP waveguide is the superposition result of the two split‐mode wave components.

Small attenuation negative group delay of spoof surface plasmon polaritons

“…It corresponds to the measured frequency band of 6.66-6.80 GHz and a maximum NGD of-0.59 ns is obtained at 6.71 GHz. Obviously, compared with the previous work [7,16], where the transmission attenuation in the NGD band exceeds 15 dB, this proposed structure has the advantages of lower attenuation. Despite having a NGD as well, the transmission forbidden band attenuates significantly.…”

“…All these suggest that while the field energy is more concentrated on the metal side with negative permittivity, the SPP mode can be expected to have a NGV effect. From wave propagation perspective, the synthetic vortex wave essence for the propagation modes of NGV features is proposed, forming a quadrupole model for the realization of negative group delay [6,7]. Therefore, for spoof-insulator-spoof (SIS) guided wave structures, negative group velocity can only be realized while the slots facing the two interfaces are not perfectly symmetric [8][9][10].…”