Broadband Negative Refraction with a Crossed Wire Mesh

It is demonstrated that a structured material formed by nonconnected crossed metallic wires may enable negative refraction over a wide frequency range. This phenomenon is a consequence of the anomalous dispersion characteristics of the material, particularly of the fact that the isofrequency contours are hyperbolic. These properties rely on the nonlocal response of the crossed wire mesh, and establish a different paradigm for obtaining negative refraction without left-handed materials.