Transformation Electromagnetics for Antennas With an Illusion on the Radiation Pattern

Using transformation electromagnetics concept, we introduce an approach to virtually delocalize radiating sources and to transform their radiation pattern at the same time. We propose the design of an electromagnetic device that can virtually change the location of the emission point. By applying radial transformations that compress space, and then match it to the surrounding environment, we show how the emission of a radiating element placed in a core region can be delocalized in a second impedance-matched region, corresponding to a space folding. Moreover, the radiation pattern of the virtual source can be modified such that an omnidirectional radiation can be changed into a directive one. We describe the space coordinate transformation and the calculation of the material parameters. Full-wave simulations are performed at different frequencies to validate the proposed approach.