Ultra-compact planoconcave zoned metallic lens based on the fishnet metamaterial

A 1.5 lambda(0)-thick planoconcave zoned lens based on the fishnet metamaterial is demonstrated experimentally at millimeter wavelengths. The zoning technique applied allows a volume reduction of 60% compared to a full fishnet metamaterial lens without any deterioration in performance. The structure is designed to exhibit an effective refractive index n = -0.25 at f = 56.7 GHz (lambda(0) = 5.29 mm) with a focal length FL = 47.62 mm = 9 lambda(0). The experimental enhancement achieved is 11.1 dB, which is in good agreement with simulation and also with previous full fishnet metamaterial lenses and opens the door for integrated solutions. (c) 2013 AIP Publishing LLC.