Geometry free materials enabled by transformation optics for enhancing the intensity of electromagnetic waves in an arbitrary domain
Ali Abdolali, Hooman Barati Sedeh, Mohammad Hosein Fakheri
Abstract
The concentration of electromagnetic waves is of utmost importance in many engineering applications such as energy harvesting devices. According to the transformation optics methodology, a feasible approach for obtaining arbitrary shape concentrators is proposed. Contrary to the previous works, the obtained materials are homogeneous and independent of the concentrator shape. That is, regardless of the input geometry, always one constant material, which is optic-null medium (ONM), is used, and the performance of the device will not alter. This competency will ease the design process and circumvent the sophisticated calculations of the necessitating materials. To demonstrate such a capability, several numerical full-wave simulations were performed for different shapes of concentrators. Furthermore, with the aid of effective medium theory (EMT), the ONM was realized using split-ring resonator-meander line metamaterial blocks. Then, as a proof of concept, an arbitrary shape concentrator was designed according to EMT and by exploiting the retrieved parameters of the realized metamaterials. It was observed that the realization results exhibit strong agreement with the theoretical investigations and corroborate the generality and effectiveness of the proposed designing method.