Subwavelength metallic waveguides loaded by uniaxial resonant scatterers

TL;DR

This paper analyzes how periodically loaded uniaxial resonant scatterers affect the dispersion properties of metallic waveguides, revealing new propagating modes below cutoff that can enable waveguide miniaturization.

Contribution

It provides an analytical theory for waveguides loaded with uniaxial resonant scatterers, considering various orientations and types, to understand their dispersion characteristics.

Findings

Waveguides support propagating modes below cutoff near resonant frequencies.

Modes are mostly forward, except for transversely oriented magnetic scatterers which produce backward modes.

The effects can be used for miniaturizing guiding structures.

Abstract

The dispersion properties of rectangular metallic waveguides periodically loaded by uniaxial resonant scatterers are studied with help of an analytical theory based on the local field approach, the dipole approximation and the method of images. The cases of both magnetic and electric uniaxial scatterers with both longitudinal and transverse orientations with respect to the waveguide axis are considered. It is shown that in all considered cases waveguides support propagating modes below cutoff of the hollow waveguide within some frequency bands near the resonant frequency of the individual scatterers. The modes are forward ones except the case of transversely oriented magnetic scatterers when the mode turns out to be backward. The described effects can be applied for the miniaturization of the guiding structures.