With the explosion of wireless networks and automotive radar systems, there is an acute need for new materials and technologies that would not only minimize the size of these devices, but also enhance their performance. The technique of transformation optics—an innovative approach to produce artificial metamaterials that control electromagnetic waves as if space itself was transformed—provides unique opportunities to reach this goal. In this paper we design, fabricate, and characterize a new class of metamaterial capable of transforming the source distribution and radiation pattern of an isotropic microwave emitter. Our findings have considerable implications for the development of new ultradirective antennas with superior performances and compactness compared to conventional antennas operating in the same frequency range.

• Received 21 October 2010

DOI:https://doi.org/10.1103/PhysRevB.83.155108