Equivalent Theory and Retrieval of Effective Metamaterials Parameters

TL;DR

This paper presents a novel graphical retrieval method for effective metamaterials parameters that improves accuracy and reduces ambiguity in measurements, applicable to anisotropic materials and capable of determining tensor components from a single layer.

Contribution

It introduces a general unit-cell design criterion and a graphical retrieval technique with phase unwrapping for effective parameter extraction in anisotropic metamaterials.

Findings

Reduces uncertainty in experimental measurements

Simultaneously retrieves six tensor parameters

Applicable to single-layer unit-cell structures

Abstract

We apply the equivalent theory to orthorhombic anisotropic materials and provide a general unit-cell design criterion for achieving a length-independent retrieval of the effective material parameters from a single layer of unit cells. We introduce a graphical retrieval method and phase unwrapping techniques. The graphical method utilizes the linear regression technique. Our method can reduce the uncertainty of experimental measurements and the ambiguity of phase unwrapping. Moreover, the graphical method can simultaneously determine the bulk values of the six effective material parameters, permittivity and permeability tensors, from a single layer of unit cells.