A simple construction for a cylindrical cloak via inverse homogenization

TL;DR

This paper presents a straightforward method to construct a cylindrical electromagnetic cloak using inverse homogenization of simple composite materials, enabling practical realization of cloaking devices.

Contribution

It introduces an inverse homogenization approach to design uniaxial dielectric-magnetic materials for cloaking, utilizing simple isotropic components with spheroidal particle shapes.

Findings

Homogenized composite materials can achieve the anisotropy needed for cloaking.

Inverse Bruggeman formalism estimates component shapes and properties.

A practical pathway for fabricating cloaks from simple materials.

Abstract

An effective cylindrical cloak may be conceptualized as an assembly of adjacent local neighbourhoods, each of which is made from a homogenized composite material (HCM). The HCM is required to be a certain uniaxial dielectric-magnetic material, characterized by positive-definite constitutive dyadics. It can arise from the homogenization of remarkably simple component materials, such as two isotropic dielectric-magnetic materials, randomly distributed as oriented spheroidal particles. By carefully controlling the spheroidal shape of the component particles, a high degree of HCM anisotropy may be achieved, which is necessary for the cloaking effect to be realized. The inverse Bruggeman formalism can provide estimates of the shape and constitutive parameters for the component materials, as well as their volume fractions.