Broadband microwave absorption by logarithmic spiral metasurface

TL;DR

This paper introduces a broadband microwave metasurface using logarithmic spiral resonators that achieve over 95% absorption across 6-37 GHz, leveraging scale invariance and Fabry-Perot resonances.

Contribution

It demonstrates a novel design of logarithmic spiral metasurfaces for efficient broadband microwave absorption, exploiting scale invariance and vortex energy flow.

Findings

Achieves >95% absorption from 6 GHz to 37 GHz.

Utilizes scale-invariant spiral resonators and Fabry-Perot resonances.

Highlights the role of vortex energy flow in absorption.

Abstract

We propose to use logarithmic spiral resonators for efficient absorption of microwaves. By combining their scale invariant geometries and Fabry-Perot-type resonances stemming from the fundamental TM mode, we realize a microwave metasurface with broadband absorption performance. The metasurface comprises logarithmic spiral resonators backed with a metallic surface and it can absorb >95% of incident microwave energy within the frequency range of 6 GHz - 37 GHz. We discuss the physics underlying the broadband absorption and the crucial role of vortex energy flow. The study opens a new direction of electromagnetic wave absorption by employing the scale invariance of Maxwell equations.