4-New metamaterial structure with reconfigurable refractive index at 5G candidate band

BAF Esmail, HA Majid, ZZ Abidin, SH Dahlan, MKA Rahim, O Ayop, “New metamaterial structure with reconfigurable refractive index at 5G candidate band,” J Optoelectron Adv M, vol. 21, pp. 101-107, 2019.

Abstract- Metamaterials are arrays of microstructure elements whose electromagnetic properties could be flexibly engineered. Unusual responses to electromagnetic indicate many noteworthy properties, such as negative refractive index and inverse Doppler shift, because of negative permittivity and permeability [1]. In 1967, the theoretical base of the unnatural physical properties of metamaterials was first introduced by Russian scientist Victor Veselago. However, these properties were hidden for 30 years, until Pendry verified them experimentally in 1996 [2],[3]. Recently, metamaterials have been extensively explored because of their numerous important applications; for example, they are used as perfect absorbers [4] and demonstrate the cloaking phenomenon [5]. Moreover, metamaterials were used for beam steering applications in the millimeter wave (MMW) band [6]. By loading metamaterials with a planar single-element antenna, the incident electromagnetic wave undergoes different refractive indexes and guides the antenna’s main beam toward the desired direction. Narrow bandwidth and losses are the main drawbacks of metamaterials, which affect the scope of their applications. At a high frequency range, such as MMW and terahertz bands, metamaterials suffer very high losses. The unnatural electromagnetic properties of metamaterials are negatively affected by these inherent losses [7]. Thus, a new low-loss metamaterial configuration is in high demand to enhance the performance of metamaterial devices, especially at a high frequency range.

Keywords: Metamaterials, reconfigurable, 5G-frequency