A Microwave Anapole Source Based on Electric Dipole Interactions Over a Low-Index Dielectric

TL;DR

This paper demonstrates a compact, low-cost dielectric-based anapole source that suppresses radiation through electric dipole interference, with potential applications in sensing and wireless technologies.

Contribution

It introduces a novel low-index dielectric disk design excited by a split ring resonator to achieve an anapole state, supported by analytical, numerical, and experimental validation.

Findings

Supports anapole state with minimal radiation

Achieves radiation suppression via destructive interference

Matches numerical and experimental results

Abstract

The pursuit of non-radiating sources and radiation-less motion for accelerated charged particles has captivated physicists for generations. Non-radiating sources represent intricate current charge configurations that do not emit radiation beyond their source domain. In this study, we investigate a single non-radiating source, comprising a low-index dielectric disk excited by a split ring resonator. Employing analytical and numerical methods, we demonstrate that this configuration supports an anapole state, exhibiting minimal or no radiation, effectively representing a non-radiating source. The radiation suppression is accomplished through the destructive interference of electric dipoles excited on the metallic and dielectric components of the proposed prototype. Transforming the design into a cost-effective device capable of suppressing radiation, we achieve impressive numerical and experimental agreement, affirming the formation of the anapole state using the lowest order multi-poles. Moreover, the devised anapole device is remarkably compact, constructed from a low-index dielectric, and employs readily available components. As a versatile platform, the proposed device can spearhead anapole research for diverse applications, including sensing, wireless charging, RFID tags, and other non-linear applications.