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Author for correspondence: Md. Jubaer Alam, E-mail: [email protected]
Introduction
Metamaterials are actually the special type of engineered materials that are usually not available in nature. They need to embed periodic unit cell for their formation to create naturally unavailable electromagnetic properties. Moreover, these materials have the power to control the electromagnetic wave beams to show their unorthodox characteristics. These unusual features of the metamaterials totally depend on the geometry of the atomic construction. It has been started from the year 1968, Veselago [1] observed unique properties of materials having negative permittivity (ε) and permeability (μ). However, it was not appreciated until 2000 when Smith et al. [2] validated a new unreal with these unconventional properties (both permittivity and permeability were negative) is called left-handed metamaterial. In case of negativity, it has been categorized as single-negative (either permittivity is negative or permeability is negative) and double-negative (both permittivity and permeability are negative). There is also a term called near-zero refractive index metamaterial (NZRI) where permittivity and permeability of a material become nearly zero on a particular range of frequency. Having these captivating electromagnetic phenomena, necessary applications, such as SAR reduction [3, 4], superlenses, antenna design [5–7], filters [8–10], invisibility cloaking [11, 12], electromagnetic absorber, and electromagnetic band gaps can be employed by metamaterials. In some cases, intrinsic negative permittivity is found; yet, it is rare to find negative permeability with a natural medium. Even artificial structures can hardly obtain the negative permeability. Concurrently, it is really difficult to get the negative refractive indices. Currently, multi-band metamaterial absorbers have become an auspicious application in the detection of explosives, even in bolometers, and thermal detectors [13]. Moreover, a very few studies have been made in designing this type of materials [14–16]. Different alphabetic shapes have become popular for particular operations; for example, Benosman and Hacene [17] introduced a double S-shaped metamaterial that showed negative values of refractive index (η) from 15.67 to 17.43 GHz. Mallik et al. [18] proposed various U-shaped rectangular array structures left-handed aspect at approximately 5, 6, and 11 GHz. A V-shaped metamaterial was presented by Ekmekci and Turhan-Sayan [19], dual-band tunable negative refractive index metamaterial with F-shape structure was presented by Rizwan et al. [20], the architecture...