A filling-factor engineered, perfect metamaterial absorber for multiple applications at frequencies set by IEEE in C and X bands

Broadband near unity absorption meta-structure for solar thermophotovoltaic systems and optical window applications

“…Nicolson–Ross–Weir (NRW) and direct refractive index (DRI) methods are utilized in ref. 88, 89, 91 and 92 to determine the permittivity and permeability of the suggested meta-structure unit cell. Both methods are represented using eqn (13) and (14), where r yy , r xx , r yx , and r xy are retrieved from CST MWS 2021 using the correct commands and consequently ε r and μ r values are computed using Matlab software.Here, is the wave number and d is the substrate thickness.…”

Homogenization of the vertically stacked medium frequency magnetic metamaterials with multi-turn resonators

“…The distribution of magnetic field on the surfaces of Port 1 and Port 2 is the most important since magnetic field values are used to find the scattering parameters S 11 and S 21 45 . These parameters and equations allow identifying the effective permeability of the metamaterial 13 .…”

“…Due to an ability to exhibit unordinary properties, for instance a zero or negative permittivity and permeability 1 – 4 , a potential interest of creating new functional structures had risen. The synthesis of superlenses 5 , 6 , cloaks 7 – 9 , new types of antennas 2 , 10 and absorbers 11 – 13 and devices for medical diagnosis 14 , 15 are some of many considered applications. Recent advances in terahertz metamaterials also show an accelerating progress of tunable metastructures 16 , 17 , where a resonance wavelength can be tuned using appropriate external fields.…”

“…The extraction of medium frequency metamaterials effective properties is the most important part of their analysis. The homogenization of the unit cell can be performed using several methods, such as field averaging 41 , Bloch wave 42 – 44 or scattering parameters (S-parameters) 13 , 45 . These methods, however, are based on a spatial field distribution, which is obtained predominantly from three-dimensional (3D) numerical model solved in a frequency domain.…”

Enhanced microwave absorption of refractory SiBCN metamaterials

“…Metamaterials, artificially manufactured and absent in nature, typically exhibit negative refraction, negative permittivity, negative permeability, and perfect absorption due to strong coupling effects, usually achieving an RL of less than −10 dB 13,14 . Hossain utilized a metamaterial composed of double E‐shaped symmetric split ring resonators, Wang employed carbon nanotube periodic gratings, and Hannan implemented identical concentric copper SRRs to achieve strong resonance effect 15–17 . The absorption rates achieved were 99.9% (−40 dB), 99.9% (−38.7 dB), and 99.5% (−30 dB), respectively.…”