Full-wave finite-difference time-domain simulation of electromagnetic cloaking structures

TL;DR

This paper develops a dispersive FDTD method to simulate electromagnetic cloaking, demonstrating that ideal cloaks can render objects invisible, while simplified cloaks have limited effectiveness unless high-order transformations are used.

Contribution

It introduces a radial dependent dispersive FDTD approach for accurate modeling of electromagnetic cloaks with Drude dispersion, and compares the effectiveness of different transformation-based cloaks.

Findings

Ideal cloaks achieve invisibility in simulations.

Simplified linear transformation cloaks have high back scattering.

High-order transformation cloaks improve cloaking performance.

Abstract

This paper proposes a radial dependent dispersive finite-difference time-domain method for the modelling of electromagnetic cloaking structures. The permittivity and permeability of the cloak are mapped to the Drude dispersion model and taken into account in dispersive FDTD simulations. Numerical simulations demonstrate that under ideal conditions, objects placed inside the cloak are `invisible' to external electromagnetic fields. However for the simplified cloak based on linear transformations, the back scattering has a similar level to the case of a PEC cylinder without any cloak, rendering the object still being `visible'. It is also demonstrated numerically that the simplified cloak based on high-order transformations can indeed improve the cloaking performance.