Abstract-Exploiting the dispersion of the double-negative-index fishnet metamaterial to create a broadband low-profile metallic lens

Exploiting the dispersion of the double-negative-index fishnet metamaterial to create a broadband low-profile metallic lens B. Orazbayev, V. Pacheco-Peña, M. Beruete, and M. Navarro-Cía  »View Author Affiliations

http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-23-7-8555

Optics Express, Vol. 23, Issue 7, pp. 8555-8564 (2015)
http://dx.doi.org/10.1364/OE.23.008555

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Metamaterial lenses with close values of permittivity and permeability usually display low reflection losses at the expense of narrow single frequency operation. Here, a broadband low-profile lens is designed by exploiting the dispersion of a fishnet metamaterial together with the zoning technique. The lens operates in a broadband regime from 54 GHz to 58 GHz, representing a fractional bandwidth ~7%, and outperforms Silicon lenses between 54 and 55.5 GHz. This broadband operation is demonstrated by a systematic analysis comprising Huygens-Fresnel analytical method, full-wave numerical simulations and experimental measurements at millimeter waves. For demonstrative purposes, a detailed study of the lens operation at two frequencies is done for the most important lens parameters (focal length, depth of focus, resolution, radiation diagram). Experimental results demonstrate diffraction-limited ~0.5λ transverse resolution, in agreement with analytical and numerical calculations. In a lens antenna configuration, a directivity as high as 16.6 dBi is achieved. The different focal lengths implemented into a single lens could be potentially used for realizing the front end of a non-mechanical zoom millimeter-wave imaging system.

© 2015 Optical Society of America