Transmission-Line Analysis of Epsilon-Near-Zero (ENZ)-Filled Narrow Channels

TL;DR

This paper investigates the physical mechanisms of resonant tunneling and supercoupling in epsilon-near-zero (ENZ) filled narrow channels using a transmission-line model, accounting for dispersion and losses.

Contribution

It extends existing theory to include dispersion and losses, providing insights into tunneling phenomena and enabling design of waveguide structures with arbitrary bends and simplified geometries.

Findings

Reveals differences between tunneling and Fabry-Perot resonances.

Provides a transmission-line model incorporating dispersion and losses.

Lays foundations for designing waveguides with complex bends and geometries.

Abstract

Following our recent interest in metamaterial-based devices supporting resonant tunneling, energy squeezing and supercoupling through narrow waveguide channels and bends, here we analyze the fundamental physical mechanisms behind this phenomenon using a transmission-line model. These theoretical findings extend our theory, allowing us to take fully into account frequency dispersion and losses and revealing the substantial differences between this unique tunneling phenomenon and higher-frequency Fabry-Perot resonances. Moreover, they represent the foundations for other possibilities to realize tunneling through arbitrary waveguide bends, both in E and H planes of polarization, waveguide connections and sharp abruptions and to obtain analogous effects with geometries arguably simpler to realize.