Realizing broadband electromagnetic transparency with a graded-permittivity sphere

TL;DR

This paper demonstrates broadband electromagnetic transparency using a graded-permittivity sphere, achieving low scattering across wide frequencies through theoretical design and numerical simulations, with practical multi-shell structures proposed for experimental realization.

Contribution

It introduces a novel graded-permittivity sphere design for broadband transparency and proposes a multi-shell structure to facilitate experimental implementation.

Findings

Achieves low scattering cross section over a wide frequency range

Reveals dynamic polarization cancellation mechanism

Proposes multi-shell sphere design for practical realization

Abstract

Broadband electromagnetic transparency phenomenon is realized with a well-designed graded-permittivity sphere, which has an extremely low scattering cross section over a wide frequency range, based on the generalized Mie scattering theory and numerical simulation in full-wave condition. The dynamic polarization cancellation is revealed by studying the variation of the polarization with respect to the frequency. Furthermore, a properly-designed multi-shell sphere is also proposed and examined in order to reduce the rigorous conditions for realizing the broadband transparency in experiments.