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An ultra-thin, multiband, micro-slot based metamaterial absorber is presented in this paper. The proposed unit cell is compact which is in the form of single-layer gold patch-gallium arsenide-ground package, involving four identical micro-slots. Using the micro-slots, the fundamental circular patch gains a multiband resonation skill, and the absorber operates at 1.16, 2.73, and 4.57 THz bands with near-perfect absorptivity. The absorption mechanism is discussed based on the electric and surface current distributions, and all outcomes are also validated by the effective medium approach. The proposed absorber is ultra-thin with a thickness of 2.6 µm, corresponding to ∼λ/100 at its lowest operation frequency. The unit cell indicates polarization-independent, and wide incident angle absorption spectra up to 40°, hence, the proposed absorber is a promising candidate as an absorbing platform for THz band imaging and sensing applications. [ABSTRACT FROM AUTHOR]

Nanostructured microwave absorbing materials attract researchers because of their ability to combat electromagnetic (EM) pollution generated by high-speed electronic gadgets without interrupting gadget mobility. In the reported work, the nanosized meta copper material C2101 Kopu Tharma Loham also called nano twin crystalline copper metal fabricated as per ancient Indian metallurgical technology is characterized to ensure its microwave absorbing properties. X-ray diffraction analysis reveals that the particle size of meta copper samples is 100 nm. Further, the melting temperature of meta copper material is 1135ºC higher than copper metal (1085ºC as per International copper standards) making the absorber thermally stable. The EM properties have been experimentally measured through different techniques for frequency ranging from 2 to 40 GHz. The loss tangent plots show that the proposed material performs better in X band. The reflection loss graphs are plotted for different sample thickness values and optimal reflection loss dip of −34.4 dB is obtained at 9.5 GHz for thickness of 2.2 mm. Proposed absorbing material can be integrated on an array substrate for sidelobe level reduction or can be incorporated on aircraft surface for radar cross-section reduction. [ABSTRACT FROM AUTHOR]