Analytical Method for Metasurface-Based Cloaking Under Arbitrary Oblique Illumination

TL;DR

This paper presents an analytical approach to design metasurface cloaks that reduce scattering of antennas under arbitrary oblique illumination, verified through microwave experiments and adaptable to higher frequency regimes.

Contribution

It introduces a new analytical method for optimizing anisotropic impedance metasurfaces for cloaking, applicable to various incident fields and realistic antenna scenarios.

Findings

Effective scattering reduction demonstrated in microwave cloaking scenarios

Metasurface design with subwavelength structures validated

Method applicable to magnetic dipole and potential higher-frequency regimes

Abstract

The performance of antennas can severely deteriorate in the presence of adjacent electrically-large scatterers. In this work, we use a conducting hollow cylinder to shield the scatterer. The cylinder is shelled with single layer dielectric and electromagnetic metasurface. The scattering field analysis with respect to the surface impedance is derived. By optimizing the anisotropic impedance distribution, the scattering cross-section can be effectively reduced. The proposed method is valid for both TMz, TEz and non-TM/TE incident field. The accuracy and effectiveness of the method are verified by four cloaking scenarios in microwave regime. We demonstrate that with the surface impedance obtained by our method, a metasurface is designed with physical subwavelength structure. We also show a cloaking scenario under magnetic dipole radiation, which is closer to the case of a realistic antenna. This method can be further applied to cloaking tasks in terahertz and optical regimes.