Generalized Sheet Transition Conditions (GSTCs) for a Metascreen -- A Fishnet Metasurface

TL;DR

This paper derives generalized sheet transition conditions for fishnet metasurfaces using homogenization, linking surface parameters to aperture geometry, and clarifies differences from other metasurface types.

Contribution

It introduces GSTCs for fishnet metasurfaces with a homogenization approach and interprets parameters in terms of aperture geometry.

Findings

GSTCs derived for fishnet metasurfaces.

Effective surface susceptibilities related to aperture shape.

Differences between GSTCs for metascreens and metafilms clarified.

Abstract

We used a multiple-scale homogenization method to derive generalized sheet transition conditions (GSTCs) for electromagnetic fields at the surface of a metascreen---a metasurface with a "fishnet" structure. These surfaces are characterized by periodically-spaced arbitrary-shaped apertures in an otherwise relatively impenetrable surface. The parameters in these GSTCs are interpreted as effective surface susceptibilities and surface porosities, which are related to the geometry of the apertures that constitute the metascreen. Finally, we emphasize the subtle but important difference between the GSTCs required for metascreens and those required for metafilms (a metasurface with a "cermet" structure, i.e., an array of isolated (non-touching) scatterers).