Low-frequency metamaterial absorber with small-size unit cell based on corrugated surface

This paper reports an independently tunable graphene-based metamaterial absorber (GMA) designed by etching two cascaded resonators with dissimilar sizes in the unit cell. Two perfect absorption peaks were obtained at 6.94 and 10.68 μm with simple single-layer metal-graphene metamaterials; the peaks show absorption values higher than 99%. The mechanism of absorption was analyzed theoretically. The independent tunability of the metamaterial absorber (MA) was realized by varying the Fermi level of graphene under a set of resonators. Furthermore, multi-band and wide-band absorption were observed by the proposed structure upon increasing the number of resonators and resizing them in the unit cell. The obtained results demonstrate the multipurpose performance of this type of absorber and indicate its potential application in diverse applications, such as solar energy harvesting and thermal absorbing.

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Triple-band low frequency ultra-compact metamaterial absorber

Journal of Applied Physics ◽

10.1063/1.4920994 ◽

2015 ◽

Vol 117 (18) ◽

pp. 184503 ◽

Cited By ~ 9

Author(s):

Baoqin Lin ◽

Shanghong Zhao ◽

Xinyu Da ◽

Yingwu Fang ◽

Jiajun Ma ◽

...

Keyword(s):

Low Frequency ◽

Metamaterial Absorber ◽

Triple Band

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Subwavelength Metamaterial Unit Cell for Low-Frequency Electromagnetic Absorber Applications

Scientific Reports ◽

10.1038/s41598-018-35267-w ◽

2018 ◽

Vol 8 (1) ◽

Cited By ~ 9

Author(s):

Heijun Jeong ◽

Toan Trung Nguyen ◽

Sungjoon Lim

Keyword(s):

Low Frequency ◽

Unit Cell

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Planar Dual Polarized Metasurface Array for Microwave Energy Harvesting

Electronics ◽

10.3390/electronics9121985 ◽

2020 ◽

Vol 9 (12) ◽

pp. 1985

Author(s):

Maged A. Aldhaeebi ◽

Thamer S. Almoneef

Keyword(s):

Energy Harvesting ◽

Dielectric Substrate ◽

Metamaterial Absorber ◽

Absorption Efficiency ◽

Unit Cell ◽

Resistive Load ◽

Electromagnetic Energy Harvesting ◽

Absorbed Power ◽

Simulation Results ◽

Dual Polarized

The design of a dual polarized metasurface collector based on the metamaterial full absorption concept for electromagnetic energy harvesting is introduced. Unlike previous metamaterial absorber designs, here the power absorbed is mostly dissipated across a resistive load rather than within the dielectric substrate. This is achieved by channeling the absorbed power to an optimal resistive load through a via hole. The simulation results show that a power absorption efficiency of 98% is achieved at an operating frequency of 2 GHz for a single unit cell. A super unit cell consisting of four cells with alternating vias was also designed to produce a dual polarized metasurface. The simulation results yielded a radiation to AC efficiency of around 98% for each polarization.

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An Ultra-Thin Low-Frequency Tunable Metamaterial Absorber Based on Lumped Element

Radioengineering ◽

10.13164/re.2019.0579 ◽

2019 ◽

Vol 27 (3) ◽

pp. 579-584 ◽

Cited By ~ 2

Author(s):

G. W. Zhang ◽

J. Gao ◽

X. Y. Cao ◽

H. H. Yang ◽

L. R. Jidi

Keyword(s):

Low Frequency ◽

Metamaterial Absorber ◽

Lumped Element ◽

Frequency Tunable ◽

Tunable Metamaterial

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Low Frequency Raman Modes of Bi2 −x PbxSr1.6Ln0.4CuO6 −δ

Materials Science Forum ◽

10.4028/www.scientific.net/msf.700.11 ◽

2011 ◽

Vol 700 ◽

pp. 11-14

Author(s):

Benjamin P. P. Mallett ◽

Thierry Schnyder ◽

Grant V. M. Williams ◽

Jeffery L. Tallon

Keyword(s):

Experimental Error ◽

Low Frequency ◽

Unit Cell ◽

Cell Contraction ◽

Raman Modes ◽

Oxygen Mode

Raman measurements were made on polycrystalline Bi2xPbxSr1:6Ln0:4CuO6 for Ln=fLa,Nd, Sm, Eug with various x and doping states. Our measurements suggest a signi cant Bicontribution to the 118cm1 mode but not to the 70cm1 mode which instead shifts to lowerfrequencies with increasing number of CuO2 layers in the Bi-based family. Shifts in the O(2)Srapical oxygen mode can be attributed to unit cell contraction within experimental error.

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Theoretical Modeling of the N-H and N-D Stretching Bands of Hydrogen-Bonded 1-Methylthymine Crystal and Its Deuterated Form

Computing Letters ◽

10.1163/157404006779194141 ◽

2006 ◽

Vol 2 (4) ◽

pp. 205-219

Author(s):

Marek Boczar ◽

Łukasz Boda ◽

Marek J. Wójcik

Keyword(s):

Hydrogen Bonds ◽

High Frequency ◽

Molecular Crystals ◽

Low Frequency ◽

Unit Cell ◽

Fermi Resonance ◽

Bending Vibrations ◽

Theoretical Simulation ◽

Stretching Vibrations ◽

Centrosymmetric Dimers

Theoretical model for vibrational interactions in the hydrogen bonds in molecular crystals with four molecules forming two centrosymmetric dimers in the unit cell is presented. The model takes into account anharmonic-type couplings between the high-frequency N-H(D) and the low-frequency N•••O stretching vibrations in each hydrogen bond, resonance interactions (Davydov coupling) between equivalent hydrogen bonds in each dimer, resonance interdimer interactions within an unit cell and Fermi resonance between the N-H(D) stretching fundamental and the first overtone of the N-H(D) in-plane bending vibrations. The vibrational Hamiltonian, selection rules, and expressions for the integral properties of an absorption spectrum are derived. The model is used for theoretical simulation of the νs stretching bands of 1-methylthymine and its ND derivative at 300 K. The effect of deuteration is successfully reproduced by our model.

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A computational study of the molecular and crystal structure and selected physical properties of octahydridosilasequioxane, (Si 2 O 3 H 2 ) 4 . II. Vibrational analysis

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2011.0473 ◽

2011 ◽

Vol 468 (2139) ◽

pp. 851-870 ◽

Cited By ~ 4

Author(s):

C. J. H. Schutte ◽

J. A. Pretorius

Keyword(s):

Ir Spectra ◽

Phonon Dispersion ◽

Computational Study ◽

Point Group ◽

Low Frequency ◽

Vibrational Analysis ◽

Unit Cell ◽

Molecular Spectra ◽

Vibrational Modes ◽

Free Molecule

A computational study of octahydridosilasequioxane, Si 8 O 12 H 8 , as a free molecule and when embedded in the unit cell R -3, Z =3, showed that the point group of the free molecule is indeed O h , but that its crystal symmetry is reduced to C 3i . Since the molecular and site-group symmetries influence the vibrational structure of a molecule, a full computational vibrational analysis of the isolated molecule and when embedded in the crystal lattice, is reported here. The analysis of the free molecular spectra given here agrees with that of its experimental infra-red (IR)-spectra and allows the assignment of all the vibrational modes, while the computed phonon dispersion of the crystal confirms the assignment of the internal vibrational modes of the molecule in the crystal. The computed and experimental IR spectra as well as Raman spectra show no indication of serious vibrational intermolecular coupling owing to the presence of multiple molecules in the unit cell. This may be the result of a weak intermolecular vibrational coupling in the solid state, which may feature in the low-frequency modes.

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