Hyperbolic dispersion and negative refraction in a periodic perfect magnetic conductor and perfect electric conductor parallel-plate waveguide structure

Abstract

We present a numerical demonstration that a periodic structure composed of alternating perfect magnetic conductor (PMC) and perfect electric conductor (PEC) parallel-plate waveguides (PPWs), filled with dielectric materials of permittivity ɛ<inf>1</inf> and ɛ<inf>2</inf>, and separated by a gap h, exhibits hyperbolic dispersion and negative refraction. This phenomenon is enabled by surface waves confined at the PMC–PEC interfaces and disappears when the dielectric permittivities are equal (ɛ<inf>1</inf>=ɛ<inf>2</inf>), eliminating surface wave support. Furthermore, the hyperbolic nature of the dispersion is confirmed by simulated radiation patterns from a point dipole source embedded in the periodic structure. © 2025 Elsevier B.V., All rights reserved.