Perfectly Matched Metamaterials

TL;DR

This paper introduces Perfectly Matched Metamaterials (PMMs), a new class of passive, reflectionless media that enable broadband, purely refractive control of electromagnetic fields for applications like beamforming and analog computing.

Contribution

The paper presents the concept of PMMs, highlighting their simplicity, reflectionless properties, and broadband capabilities, distinct from traditional transformation optics approaches.

Findings

Analytical designs demonstrate broadband PMM capabilities

PMMs enable reflectionless, purely refractive EM field transformations

Potential applications include wideband beamforming and analog signal processing

Abstract

Fully harnessing the vast design space enabled by metamaterials to control electromagnetic (EM) fields remains an open problem for researchers. Inverse-design techniques have shown to best exploit the degrees of freedom available in design, resulting in high-performing systems for wireless communications, sensing and analog signal processing. Nonetheless, fundamental yet powerful properties of metamaterials are still to be revealed. In this paper, we introduce the concept of Perfectly Matched Metamaterials (PMMs). PMMs are passive, inhomogeneous media that perform purely refractive field transformations under different excitations. Their advantage lies in their simplicity, reflectionless behavior and suitability for both analytical and numerical design methods. Unlike Transformation Optics, PMM-based designs are devoid of coordinate transformations. Anisotropic unit cells are configured to control EM fields in a true-time delay manner. Simple analytical designs are reported which demonstrate the broadband capability of PMM devices. Proposed PMMs may find application in wideband beamforming and analog computing, realizing functionalities such as spatial filtering and signal pre-processing.