Controlling the Emission of Electromagnetic Sources by Coordinate transformation

TL;DR

This paper explores how coordinate transformations can be used to control electromagnetic emissions by designing metamaterial coatings that modify source behavior without detection, enabling advanced active EM device development.

Contribution

It introduces a novel method to manipulate electromagnetic sources using coordinate transformation media, including the design of conformal antennas and source control techniques.

Findings

Sources can be replaced by metamaterial coatings with controlled emission.

The method allows for concealment of sources from external detection.

Design principles for conformal antennas are demonstrated.

Abstract

The coordinate transformation on the space that contains electromagnetic sources is studied. We find that, not only the permittivity and permeability tensors of the media, but also the sources inside the media will take another form in order to behave equivalently as the original case. It is demonstrated that, a source of arbitrary shape and position in the free space can be replaced by an appropriately designed metamaterial coating with current distributed on the inner surface and would not be detected by outer observers, because the emission of the source can be controlled at will in this way. As examples, we show how to design conformal antennas by covering the sources with transformation media. The method proposed in this letter provides a completely new approach to develop novel active EM devices.