Broadband Cloaking Obtained Using HOBBIES Optimization [EM Progammer's Notebook]

In this article, we describe the notion of a cloak achieved by employing the usual composite dielectrics surrounding a metal cube, a concept that was first presented by Hwang and Chin [1]. Here, we use an optimization procedure to improve on their results and obtain a three-dimensional composite dielectric structure that can achieve a better broadband match than that of [1]. The two structures of interest are an empty metallic waveguide and a metal cube placed inside the same waveguide but surrounded by different-sized dielectric slabs so that the effect of the metal cube in the transmitted fields inside the waveguide will not be much different from the fields that would exist in an empty waveguide. The dimensions and properties of the simple dielectrics making up the different slabs inside the waveguide are optimized using an electromagnetic simulator called Higher Order Basis Based Integral Equation Solver (HOBBIES) [2] so that the waveguide will appear empty by looking at the nature of the transmitted fields from the waveguide loaded with a metallic cube but surrounded by some dielectrics.