Fresh metamaterials ideas for metallic lenses

In this work we provide further advances in the applications of Metamaterial concepts to the classical field of metallic lenses. Some of the limitations that metallic lenses have, such as imperfect matching with free space, can be overcome by Metamaterials, which makes them powerful tools not only in lens field but also in many others. Specifically, our work is devoted to the Extraordinary Transmission Metamaterial because of its low-losses and its potential scaling to any range of the spectrum. Firstly, we explore at the microwave regime the modification of the radiation pattern of a commercial horn antenna when 1 and 4 stacked subwavelength hole arrays are placed as a superstrate. Afterwards, the design of plano- and bi-concave ETM lenses operating at millimetre waves are analysed. Numerical analyses are confirmed by experimental results.