Boundary versus core conditions for the control of electromagnetic waves by electromagnetic transformations

We report on the possibility of controlling the radiation pattern of a quasi-point source antenna with a high directivity by means of artificial metamaterial-based cloaks. The demonstration of high directivity via the engineering of core effective parameters, with performances comparable to those obtained by conventional techniques such as parabolic mirrors, is carried out numerically by means of electromagnetic transformations. Two consecutive cartographic space transformations are performed in practice with an intermediate curved space.