Non-magnetic simplified cylindrical cloak with suppressed zero-th order scattering

TL;DR

This paper introduces a simplified non-magnetic cylindrical cloak design that effectively suppresses zero-th order scattering through a resonant gap, resulting in low scattering and good tolerance to perturbations.

Contribution

A novel non-magnetic cylindrical cloak with a resonant gap that significantly reduces zero-th order scattering and maintains low scattering with high perturbation tolerance.

Findings

Zero-th order scattering is dominant in cylindrical cloaks.

Adding a gap at the inner surface suppresses zero-th order scattering.

Numerical simulations confirm low scattering and robustness.

Abstract

A new type of simplified cloaks with matched exterior boundaries is proposed. The cloak uses non-magnetic material for the TM polarization and can function with a relatively thin thickness. It is shown that the $zero^{th}$ order scattering of such cloak is dominant among all cylindrical scattering terms. A gap is added at the cloak's inner surface to eliminate the zero-th order scattering, through the mechanism of scattering resonance. The reduction in scattering is relatively smooth, indicating that the proposed scattering reduction method has good tolerance to perturbations. Numerical simulations also confirm that the proposed structure has very low scattering.