Polarization independent broadband metamaterial absorber for microwave applications

Abstract

A new polarization independent broadband metamaterial absorber (MA) structure based on split ring resonators which are loaded with lumped elements and via connection lines is proposed. The designed structure shows a perfect absorption between 4 and 16 GHz which is validated by simulation studies. Experimental study is only made for the structure that has no via connections and no the lumped element resistors to show the importance of these entities in the proposed metamaterial structure. Both numerical and experimental study results show that broadband MA property depends on the resistors and via connections on the proposed structure. By having high absorption in a wideband range which is numerically demonstrated, the proposed structure can be used in energy harvesting or wireless power transfer applications with higher efficiencies.Metamaterials have attracted great attention owing to their unique electromagnetic and optical properties, such as negative refraction 1 and asymmetrical transmission. 2-4 One of the most popular types of metamaterial is metamaterial absorbers (MA) which was initially proposed by Landy et al. 5 in 2008. After that, different types of single band and multi band MA studies were proposed. 6,7 In addition, polarization independent and tunable perfect metamaterial absorbers (PMA) with wide incidence angles were designed in microwave, THz, and optical frequency bands. [8][9][10] Because of the diffraction limitations, traditional absorbers cannot be designed and produced in small dimensions. Since reduction in the electrical thickness of the absorbers is one of the main design inputs, the need for producing these absorbers has emerged. Tao et al. realized a study in which they achieved 96% absorption at 1.6 THz. 11 Metamaterials are also used in many areas including super lenses, 12 invisibility cloaking, 13,14 polarization rotation, 15 sensing applications, 16 antennas and energy harvesting. [17][18][19][20][21] Researchers have been working on bandwidth enhancement and polarization insensitiveness by applying different methods. [22][23][24] These methods can be listed as resistive film placement, loading lumped elements, and using multilayer structures. [25][26][27][28][29][30] In a study conducted by Tang et al., 25 resistive films which were vertically placed on the metal plate were used to increase the bandwidth. In that study, polarization independent MA was designed and its operation between 20 and 55 GHz is demonstrated. In Ref. 26, Mulla et al. obtained a bandwidth increase by using multilayer structure numerically between 624 and 658 THz. Chen et al. designed MA which was composed of a single dielectric substrate, double circular metallic rings and resistive loads operating between 8.87 and 16.47 GHz. In Ref. 27, Chen et al. studied a broadband absorber by using lumped elements and they obtained more than 7 GHz bandwidth with 90% absorption. In Ref. 28, Ding et al. conducted a study for a microwave ultrabroadband polarization independent metamaterial by using periodic array of met...

Penta Band Single Negative Meta-Atom Absorber designed on Square Enclosed Star-Shaped Modified Split Ring Resonator for S-, C-, X- and Ku- Bands Microwave Applications

“…In this analysis, the absorption bandwidth above 90% at 1140 nm and in 584 nm it above 99%. Mehmet Bagmanchi et al demonstrated a metamaterial absorber which presents in the frequency ranges 4-16 GHz, simulated broad band absorption characteristics in [12]. However, the measured result reflects weak absorption characteristics of about 8.5 GHz and 15.5 GHz with an absorption peak of 70% and 90% respectively.…”

Ultra‐thin metamaterial perfect absorbers for single‐/dual‐/multi‐band microwave applications

“…The concept of perfect metamaterial absorber (MMA) came into existence with the significant experimental work of Landy et al in 2008 [8]. Since then, numerous MMA based structures, including T-shape [7,9], split-ring structures [10], ring-shape [6,11,12], circular fractal [13], H-shape [14] and Jerusalem cross (JC) resonator [15][16][17] were proposed as a perfect multi-and broadband absorber in a wide EM-spectral regime. Several efforts have also been carried out for the advancement of multi-and broad-band MMAs by introducing coplanar or stacked multi-layer configurations employing different metallic resonant structures [5,[18][19][20].…”

A Multiple-Bands Metamaterial Absorber Based in X, Ku and K-Band

“…Moreover, polarization-independent [21][22][23][24][25] and Tunable Perfect Metamaterial Absorbers (PMA) [26][27][28][29][30] were structured in the Gigahertz, Megahertz, and also in Terahertz. Mehmat et al [31] have proposed an Absorber which consists of a split ring resonator (SRR) and it has the perfect absorption between 4 and 16 GHz. As it has high absorption so it tends to be employed in wireless power transfer applications.…”