Metamaterial covers over a small aperture

TL;DR

This paper proposes using specially designed metamaterial layers as covers over a sub-wavelength aperture in a PEC screen to significantly enhance wave transmission, supported by analytical and numerical analysis.

Contribution

It introduces a novel metamaterial cover setup for apertures, providing detailed analytical explanations and numerical validation for enhanced transmission effects.

Findings

Metamaterial covers can increase aperture transmission significantly.

Analytical models match numerical simulations.

Transmission enhancement depends on geometrical and electromagnetic parameters.

Abstract

Recently, it has been experimentally shown by several other researchers in the physics community that a properly designed periodic corrugation of a metallic opaque screen may significantly enhance the power transmission through a sub-wavelength hole in the optical frequency band. Oliner, Jackson and their co-workers explained and justified this phenomenon as the result of the excitation of the leaky waves supported by the corrugated screen. Here we suggest another setup, in which metamaterial layers with special parameters may be utilized as covers over a single sub-wavelength aperture in a perfectly electric conducting (PEC) flat screen in order to increase the wave transmission through this aperture, and we provide a detailed analytical explanation for this aperture setup that may lead to similar, more pronounced effects when the metamaterial layers are used in the entrance and the exit face of the hole in the flat PEC screen with no corrugation. Some physical insights into the function of these covers and some numerical results confirming this theory are presented and discussed. We also discuss the sensitivity of the transmission enhancement to the geometrical and electromagnetic parameters of this structure.