High-impedance surfaces having stable resonance with respect to polarization and incidence angle

TLDR

Current realizations of high‑impedance surfaces rely on planar frequency‑selective surfaces at the interface of a metal‑backed dielectric slab, with or without vertical vias. The paper presents a theoretical investigation of frequency‑selective surfaces for use as artificial magnetic conductors or high‑impedance surfaces. An analytical model was validated through HFSS simulations. The study demonstrates that series‑resonance grids without vias yield a stable, polarization‑ and angle‑independent resonance, whereas adding vias destabilizes the effect and shifts the frequency.

Abstract

The work presented in this paper concerns a theoretical study on frequency selective surfaces (FSS) with application to artificial magnetic conductors or high-impedance surfaces (HIS). Current realizations of HIS are based on a planar FSS at the interface of a metal-backed dielectric slab either including vertical vias or not. A stable resonance was found for the case of series-resonance grids without vias in the slab. The resonance turns out to be unique in theory for all angles of incidence and both polarizations of plane waves illuminating the HIS. It was shown that vias destroy the stabilization effect and introduce a frequency shift. The analytical model was validated by HFSS simulations.