Magnetless Reflective Gyrotropic Spatial Isolator Metasurface

TL;DR

This paper introduces a magnetless, birefringent metasurface that achieves polarization-based reflection and absorption, enabling nonreciprocal electromagnetic isolation without magnetic materials, demonstrated through synthesis, design, and simulation.

Contribution

It presents a novel magnetless gyrotropic metasurface design using surface susceptibilities and transistor-loaded resonators for nonreciprocal polarization control.

Findings

Successful synthesis using GSTCs

Effective polarization isolation demonstrated in simulations

Potential for advanced magnetless nonreciprocal systems

Abstract

We present the concept of a magnetless Reflective Gyrotropic Spatial Isolator (RGSI) metasurface. This is a birefringent metasurface that reflects vertically polarized incident waves into a horizontally polarized waves, and absorbs horizontally polarized incident waves, hence providing isolation between the two orthogonal polarization. We first synthesize the metasurface using surface susceptibility-based Generalized Sheet Transition Conditions~(GSTCs). We then propose a mirror-backed metaparticle implementation of this metasurface, where transistor-loaded resonators provide the desired magnetless nonreciprocal response. Finally, we demonstrate the metasurface by full-wave simulation results. The proposed RGSI metasurface may be used in various electromagnetic applications, and may also serve as a step towards more sophisticated magnetless nonreciprocal metasurface systems.