Electromagnetic Boundary Conditions Defined by Reflection Properties of Eigen Plane Waves

TL;DR

This paper explores generalized electromagnetic boundary conditions characterized by reflection properties of eigen plane waves, identifying classes with specific reflection coefficients and analyzing their wave interactions.

Contribution

It introduces a broader class of boundaries with angle-independent reflection coefficients, extending known boundary types like GSHDB and PEMC.

Findings

Two classes of boundaries with reflection coefficients R=1 and R=j are identified.

Matched waves and reflected plane waves are analyzed for these boundary classes.

The study extends understanding of boundary conditions beyond traditional PEC and PMC types.

Abstract

It is known that the two eigen plane waves incident to the generalized soft-and-hard/DB (GSHDB) boundary are reflected as from the PEC or PMC boundary, i.e., with reflection coefficients $-1$ or $+1$, for any angle of incidence. The present paper discusses a more general class of boundaries by requiring that the reflection coefficients $R_+$ and $R_-$, corresponding to the two eigen plane waves, have opposite values, $R_\pm=\pm R$ with $R$ independent of the angle of incidence. It turns out that, there are two possibilities, $R=1$ for the class of GSHDB boundaries, and $R=j$ for another class, extending that of the perfect electromagnetic conductor (PEMC) boundaries. Matched waves at, and plane-waves reflected from, boundaries of the latter class are studied in the paper.