Enhancing and tuning absorption properties of microwave absorbing materials using metamaterials

Zou, Yanhong; Jiang, Leyong; Wen, Shuangchun; Shu, Weixing; Qing, Yongjun; Tang, Zhixiang; Luo, Hailu; Fan, Dianyuan

doi:10.1063/1.3062854

Cited by 47 publications

(22 citation statements)

References 14 publications

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“…The basic fabrics were as follows: a; spunbond-meltblown-spunbond (SMS) type polyester (PET) nonwoven fabric (Asahi-Kasei, CC5020, specific gravity (SG) =0.2 g/cm 3 ), b; PET /ethylene-vinyl and W 2 are the weights of a fabric piece before and after CNT coating, respectively, and C is the weight ratio of CNTs to all the solid contents included in the suspension. The porosity was defined as…”

Section: Fabrication and Evaluation Methodsmentioning

confidence: 99%

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Electromagnetic absorbing materials using nonwoven fabrics coated with multi-walled carbon nanotubes

Sano

Akiba

2014

Carbon

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We calculated the complex permittivity of materials required to achieve a single-layer electromagnetic absorber with a high absorption coefficient in the 60-GHz band. The calculation results indicated that an absorption coefficient of 0.95 can be achieved for a 5-mm sheet when the real part of the relative permittivity  r ' is close to that of the free space and the conductivity  is around 3 S/m. On the basis of the findings, we developed three types of nonwoven fabrics with high porosity in which the fibers were coated with multi-walled carbon nanotubes (MWCNTs). The  r ' of 1.12-1.32 and  of 0.107-12.4 S/m were obtained depending on the porosity of the fabrics. The measured absorption coefficients reached 0.97 at 60 GHz in agreement with the calculations. The present MWCNTs-coated nonwoven fabrics will be useful materials for high performance electromagnetic absorbers.

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Section: Fabrication and Evaluation Methodsmentioning

confidence: 99%

“…A sophisticated optimization technique such as a genetic algorism (GA) is needed to widen the bandwidth [1]. To thin the absorbers, a frequency selective surface (FSS) [2] and a metamaterial surface [3] have been introduced. In these types of absorbers, the operating bandwidth is determined by the surface frequency characteristics.…”

Section: Introductionmentioning

confidence: 99%

Electromagnetic absorbing materials using nonwoven fabrics coated with multi-walled carbon nanotubes

Sano

Akiba

2014

Carbon

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“…The results demonstrate that electromagnetic wave can be perfectly absorbed around 8 GHz via the present design. These could provide a method of enhancing an absorption properties of microwave absorbing materials using metamaterials [14] . Simultaneously, it is possible to extend the bandwidth of metamaterials by adjusting the scales, shapes and arrangement of unit cell [15] .…”

Section: ⅲ Results and Discussionmentioning

confidence: 99%

Experimental Investigation of R(ω), T(ω) and L(ω) for Multi-Layer SRRs and Wires Metamaterials

Luo¹,

Wang²,

Liao

et al. 2010

Journal of electromagnetic engineering and science

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Reflection(R(ω)), transmission(T(ω)) and loss(L(ω)) characteristics of multi-layer metamaterials are investigated experimentally in free space with the incident EM waves perpendicular to the substrate plane. The sample is made of split-ring resonators(SRRs) and wires which are the typical model of metamaterials. The R(ω) and T(ω) of multi-layer metamaterials have been calculated from the measured S-parameters. In this paper, we got the impedancematched result according to the curves of R(ω), meanwhile the T(ω) decreased with increasing number of layers. At last, we attained the result that the L(ω) gets to nearly 98% around 8 GHz, with R(ω)=T(ω)=0. The design presented in this paper achieves experimented loss near unity. Ⅰ. IntroductionRecently, metamaterials with a negative index of refraction have attracted great attention due to their fascinating electromagnetic(EM) properties. It was Veselago who introduced the term "left-handed substances" in his seminal work published in 1968 [1] . Until 1996, Pendry et al. successively proposed a theoretical model that could realize negative permittivity by periodic arrangement of metallic wires [2] and negative permeability by periodic array of split-ring resonators(SRRs) [3] . In 2000, Smith et al. designed artificial materials at microwave frequen cies [4] , and the negative refraction was also experimentally verified in the wedge prism of metamaterials [5] . Metamaterials have many peculiar electromagnetic properties, such as reversed Doppler shift [6] , Cherenkov radiation [7] , and Snell effect [8], [9] , etc. At present, the research of metamaterials focuses on the incident EM wave parallel to the metamaterials samples plane. Most experiment used lithography which etches the cycle with single-layer structure of metal pattern on media substrate. Because it is difficult to realize the structure design of metamaterials by the methods of paralleling to the substrate plane. There is an urgent need to allow the incident EM waves to be perpendicular to the substrate plane [10] . In this work, we mainly reported the experiment of reflection, transmission and losses of metamaterials with the incident electromagnetic wave perpendicular to the sample substrate plane. The sample was the typical model of the SRRs and wires. We have experimented for multi-layer metamaterials in free space. The characteristics of the R(ω), T(ω) and L(ω) of metamaterials with various layers were investigated in detail. Fig. 1 shows the structure of the designed samples. The samples consisted of an array of the SRRs and continuous wires. Fig. 1(a) illustrates the structure of SRRs, where r presents the radius of the SRRs, t is the width of each ring, w is the spacing between the two rings in a single SRRs's structure, and g is the gap of each ring. In Fig. 1(b), wires structure is illustrated, d is the width of the wire and a is the cell side of the square lattice. The size parameters are listed as the following: a=1.0 Ⅱ. Experiments 2-1 Sample Preparation-3 m, l=1.4×10 -3 m, g=3.0×10 -4 m...

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“…A group from Hunan University has demonstrated a scheme to enhance and tune absorption properties of conventional microwave absorbing materials by metamaterials 12 . They have proposed a combined metamaterials absorbing material, which is constructed by covering a single layer of metamaterials on the surface of a conventional absorbing material.…”

Section: Application Of Metamaterials In Electromagnetic Wave Absorbersmentioning

confidence: 99%

Metamaterials in Electromagnetic Wave Absorbers

Dubey¹,

Shami²

2012

DSJ

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Stealth technology in terms of absorption of electromagnetic waves is a most valuable research area for military purposes. Development of radar absorbing materials (RAM) had been actively researched for a quite long time. In the RAM design, weight, thickness, absorptivity, environmental resistance and mechanical strength are the key factors and therefore development of RAM with low density and high strength is a challenging task. As an alternative, research interest has shifted towards radar absorbing structures (RAS) and metamaterial is one of the lucrative options for the development of RAS. Metamaterials are a new class of ordered composites that exhibit exceptional electromagnetic properties not readily observed in nature. Built from microstructure that is small compared to wavelength of operation, metamaterials can be designed with effective permittivity and permeability values that can be large or small or even negative at any selected frequency. In this review paper, we first place the stealth technology in brief and then concept of metamaterials in context of conventional materials. We then discuss reflection theory of metamaterials from stealth point of view. Next section deals with recent progress towards its application as electromagnetic absorbers and future prospects especially in higher frequency region.

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Enhancing and tuning absorption properties of microwave absorbing materials using metamaterials

Cited by 47 publications

References 14 publications

Electromagnetic absorbing materials using nonwoven fabrics coated with multi-walled carbon nanotubes

Electromagnetic absorbing materials using nonwoven fabrics coated with multi-walled carbon nanotubes

Experimental Investigation of R(ω), T(ω) and L(ω) for Multi-Layer SRRs and Wires Metamaterials

Metamaterials in Electromagnetic Wave Absorbers

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