Volumetric Invisibility Cloaks Design Through Spectral Coverage Optimization

Abstract

A novel approach to the design of cloaking devices is presented which takes inspiration from the Fourier diffraction theorem. In particular, we first put on a common basis different linear approximations of the scattering equations. Then, a very simple procedure to get invisibility (under the given approximation at hand) is proposed. The approach is assessed through numerical examples concerning 3-D non-canonical objects. INDEX TERMS Fourier diffraction theorem, inverse design, linear approximations, scattering.

Inverse design of EBG waveguides through scattering matrices

“…In order to have a field representation in a unique global reference system (e.g., the ℓ-th one), the Graf's formula [29] for the Hankel function can be used. We finally obtain what follows (see [24] for more details):…”

“…wherein Q ℓ,m encodes terms arising from the harmonic expansion of the primary source, while T ℓ,i,m,q takes into account mutual coupling effects amongst scatterers [24], that is, it is related to the secondary incident field. For the sake of completeness, analytic expressions of T ℓ,i,m,q and Q ℓ,m taken from [24] are given in Appendix.…”

“…that formally describe the scattering model at hand. Once equation ( 6) is solved, the scattered field in the region of space outside scatterers can be finally evaluated through equation ( 1) [24].…”

“…As an alternative to above techniques and with the aim of overcoming relates issues, we have recently proposed, for a completely different problem concerned with antennas (see below), a novel inverse design approach based on inverse scattering co-adjuvated by the use of the so called Scattering Matrix Method (SMM) [24]. The SMM is a very accurate and fast analysis tool for structures made of multiple dielectric or metallic scatterers.…”

Inverse Design of Artificial Materials Based Lens Antennas through the Scattering Matrix Method

“…Recently, a possibility to manage the lens permittivity distribution to achieve desired radiation characteristics has been offered by the inverse scattering problem (ISP) framework [20][21][22][23].…”