Authors: Md Shakibul Hasan, Mohammad Tariqul Islam, Md Samsuzzaman, Saeed Alamri, Saleh Albadran, Md Moniruzzaman, Mohamed S. Soliman
Publication: Optics & Laser Technology, Volume 171, Pages 110334, Elsevier (2024/04/01)

A quad-band metamaterial absorber designed to be insensitive to polarization and incident angle, achieving ultra-high absorption for wireless applications. This research presents a double elliptical split ring resonator-based metamaterial absorber (MMA) for microwave applications. The design features four square outer split rings and two elliptical split rings at the center, placed over an FR-4 dielectric substrate (1.6 mm thick). The unit cell has an electrical size of 0.103λ₀ × 0.103λ₀ (λ₀ = 2.576 GHz). The MMA demonstrates maximum absorption of 99.83% at 2.576 GHz, 99.98% at 5.648 GHz, 99.56% at 8.32 GHz, and 99.15% at 13.456 GHz in TE mode, and similarly high absorptions in TM mode. The design is insensitive to polarization and incident angles (0°–90°), making it highly versatile for various wireless communication applications. The unit cell exhibits single-negative metamaterial characteristics, enabling improved performance for multi-band signal absorption and potential integration into next-generation microwave devices.