Metamaterial structures designed to have simultaneously negative permittivity and permeability are known as left-handed materials. Their complexity and our understanding of their properties have advanced rapidly to the point where direct applications are now viable. We present a radial gradient-index lens with an index of refraction ranging from −2.67 ͑edge͒ to −0.97 ͑center͒. Experimentally, we find that the lens can produce field intensities at the focus that are greater than that of the

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... ent plane wave. These results are obtained at 10.3 GHz and in excellent agreement with full-wave simulations. We also demonstrate an advanced fabrication technique using conventional printed circuit board technology which offers significant design, mechanical, and cost advantages over other microwave lens constructions.