Complementary metasurfaces for guiding electromagnetic waves

TL;DR

This paper introduces a novel waveguide design using two complementary metasurfaces with isotropic impedances, enabling control over guided modes and polarization properties for advanced electromagnetic applications.

Contribution

It presents a theoretical study of guided modes in a new metasurface-based waveguide structure with complementary impedances, including dispersion analysis and mode excitation.

Findings

Support for guided modes with tunable dispersion

Possibility to excite orthogonal polarization modes with same phase velocity

Potential applications in antennas and field focusing

Abstract

Waveguides are critically important components in microwave, THz, and optical technologies. Due to recent progress in two-dimensional materials, metasurfaces can be efficiently used to design novel waveguide structures which confine the electromagnetic energy while the structure is open. Here, we introduce a special type of such structures formed by two penetrable metasurfaces which have complementary isotropic surface impedances. We theoretically study guided modes supported by the proposed structure and discuss the corresponding dispersion properties. Furthermore, we show the results for different scenarios in which the surface impedances possess non-resonant or resonant characteristics, and the distance between the metasurfaces changes from large values to the extreme limit of zero. As an implication of this work, we demonstrate that there is a possibility to excite two modes with orthogonal polarizations having the same phase velocity within a broad frequency range. This property is promising for applications in leaky-wave antennas and field focusing.