Subwavelength Microwave Guiding by a Periodically Corrugated Metal Wire

Abstract

The guiding properties of a periodically corrugated metal wire at microwave frequencies are studied theoretically. The outer radius of the corrugated wire is of subwavelength size, and it seems difficult for spoof surface plasmon polaritons (SPPs) in the wire to be confined highly, even if the set of the geometric parameters of the wire structure is optimized. However, if the grooves of the corrugated wire are filled with a dielectric with high permittivity, the strong field confinement of spoof SPPs can be achieved even at frequencies smaller than the asymptotic frequency, for which the SPP losses are quite low. It is also shown that for this type of wire structure, the subwavelength microwave guiding is available for a certain frequency range.