Numerical study of randomly distributed wire based metamaterial absorber
01 Dec 2015-pp 92-95
TL;DR: In this article, a randomly distributed wire based metamaterial absorber is designed and analyzed numerically in microwave frequency region, which is composed of randomly distributed metallic wire on lossy FR4 substrate backed with metallic plate.
Abstract: In this article, randomly distributed wire based metamaterial absorber is designed and analyzed numerically in microwave frequency region. The metamaterial absorber is composed of randomly distributed metallic wire on lossy FR4 substrate backed with metallic plate. Twenty random coordinates are generated within a unit cell of absorber. Total forty wire elements are distributed, including twenty wires horizontally and twenty wires vertically, at these random coordinate in unit cell. The numerical result shows the bandwidth of absorber is 1.2 GHz and 2 GHz for 10 dB and 5 dB return loss respectively. The wire elements dimensions (width and thickness) are of 14 μm and 35 μm respectively. Observed multiple absorption peaks expected to correspond to the absorption modes excited by varied effective lengths of shortened randomly distributed metallic wires.
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TL;DR: This work fabricate, characterize, and analyze a MM absorber with a slightly lower predicted A(omega) of 96%.
Abstract: We present the design for an absorbing metamaterial (MM) with near unity absorbance A(omega). Our structure consists of two MM resonators that couple separately to electric and magnetic fields so as to absorb all incident radiation within a single unit cell layer. We fabricate, characterize, and analyze a MM absorber with a slightly lower predicted A(omega) of 96%. Unlike conventional absorbers, our MM consists solely of metallic elements. The substrate can therefore be optimized for other parameters of interest. We experimentally demonstrate a peak A(omega) greater than 88% at 11.5 GHz.
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TL;DR: In this paper, a broadband gigahertz region metamaterial absorber with a maximum absorption of 99.9% at 2.4 GHz and a full width at half maximum bandwidth of 700 MHz, all while maintaining low reflection inside and outside of resonance.
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TL;DR: In this article, an equivalent circuit model is developed to understand how the constitutive parameters affect the absorption properties, and some strategies for designing broadband absorbers are discussed based on the circuit model.
Abstract: Wire-based metamaterial absorbers, as a kind of simple but versatile artificial structures, have been widely investigated from microwave to optical frequencies. In order to completely understand how the constitutive parameters affect the absorption properties, an equivalent circuit model is developed in this paper. The analytical, numerical, and experimental results show that the absorption frequency is determined by the wire length and the spacer electromagnetic parameters, whereas the absorption level by the thickness of spacers and losses which include Ohmic loss of the metal as well as dielectric loss of the spacers. It is also explained why the small losses have hardly any effect on the absorption frequency, but can result in the near-unity absorption. Based on the circuit model, some strategies for designing broadband absorbers are discussed finally.
86 citations