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Negative Refraction in Infrared and Visible Domains
Published in Filippo Capolino, Theory and Phenomena of Metamaterials, 2017
Varying the geometrical parameters of the waveguide along the direction orthogonal to the plane of propagation directly affects the effective properties in the flatland plane, and, in particular, the effective index of refraction. It is worth underlining an important property of these planar metamaterials: unlike the other common ways of constructing LH metamaterials with resonant inclusions, like the one suggested in Section 23.3, here these effective 2D planar metamaterials do not rely on an individual resonant phenomenon, similar to their microwave counterparts synthesized with printed microstrip lines and lumped circuit elements [4,5]. This allows better robustness to losses and larger bandwidth of operation, i.e., better possibility for demonstrating some of the unconventional loss-sensitive features of negative-index metamaterials in the IR and visible frequency domains.
A programmable digital metasurface structure designed using ANN technique
Published in International Journal of Electronics, 2023
Gizem Altıntarla, Emin Ünal, Olcay Altıntaş, Duygu N. Gençoğlan, Şule Çolak, Amir H. Nazeri, Fatih Özkan Alkurt, Muharrem Karaaslan
In recent years, negative index metamaterials have become a remarkable topic in antenna engineering applications (Benayad & Tellache, 2019; Cicchetti et al., 2017; Islam et al., 2019; Konstantinidis & Feresidis, 2015; Safari Dehnavi et al., 2019; Saraswat & Kumar, 2019). Metasurface structures play an indispensable role in antenna design due to their functional advantages (Ashoor & Ramahi, 2019; M. Chen et al., 2019; W. Chen et al., 2017; Hou et al., 2019; Liu & Cui, 2016; Nasrollahi et al., 2018; Safari Dehnavi et al., 2019; Singh et al., 2019; La Spada, 2019; Ünal & Altıntarla, 2019). In Safari Dehnavi et al., (2019), the metamaterial surface is used as superstrate to enhance antenna characteristics. In M. Chen et al., (2019), Huygens’ metasurface structure