Broadband microwave coding metamaterial absorbers

Abstract

In this paper, a broadband metamaterial microwave absorber is designed, simulated and measured. Differently from the traditional method which is only based on unit cell boundary conditions, we carried out full-wave finite integration simulations using full-sized configurations. Starting from an elementary unit cell structure, four kinds of coding metamaterial blocks, 2 × 2, 3 × 3, 4 × 4 and 6 × 6 blocks were optimized and then used as building blocks (meta-block) for the construction of numerous 12 × 12 topologies with a realistic size scale. We found the broadband absorption response in the frequency range 16 GHz to 33 GHz, in good agreement with the equivalent medium theory prediction and experimental observation. Considering various applications of metamaterials or metamaterial absorbers in the electromagnetic wave processing, including the radars or satellite communications, requires the frequency in the range up to 40 GHz. Our study could be useful to guide experimental work. Furthermore, compared to the straightforward approach that represents the metamaterials configurations as 12 × 12 matrices of random binary bits (0 and 1), our new approach achieves significant gains in the broadband absorption. Our method also may be applied to the full-sized structures with arbitrary dimensions, and thus provide a useful tool in the design of metamaterials with specific desired frequency ranges.

Correlations between Living Values and Life Skills of Secondary School Students in Vietnam

“…This means that when students are fully equipped with living values, they will be able to express life skills and thus in other words, learners' behaviors and habits will be consolidated more firmly. This study provides clear evidence that the inclusion of living values and life skills is a correct and necessary trend -this is also the approach that has been confirmed in many theoretical and practical studies (Do, 2011;Dang, 2011;Nguyen, 2020;Nguyen et al, 2018;Lovat, 2009;Hanbury, 2008;Bartlett, 1987;Daunic et al, 2013;Covey, 2015;Payton et al, 2008;Makie, 2010;Nguyen & Tran, 2018;Nguyen et al, 2010).…”

Near-perfect broadband infrared metamaterial absorber utilizing nickel

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“…The areas of potential applications of the proposed device include sensing, detecting, light modulating, cloaking and optical buffering [2][3][4][5].…”

Physical and electrodynamic properties of nanoscale conductive films on polymer substrates

“…On the other hand, studying the electrodynamic properties of the films are interesting in view of their inclusion in complex metostructures [4], which make it possible to achieve absorption of 80-90% [5]. It should be noted that pure conductive films with thicknesses from 2 to 7 nm can significantly (up to 50%) convert the electromagnetic fields energy of the radio range of 1 ... 400 GHz [6,7] into thermal energy.…”