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Grapheme and ultra surface based working bandwidth adjustable wave absorber

A technology with working bandwidth and metasurface, which is applied in the field of absorbing materials, can solve problems such as insufficient flexibility and stability of tuning, insufficient absorbing effect, narrow absorbing bandwidth, etc., and achieve convenient and flexible tuning process, perfect absorbing characteristics, Good absorbing performance

Active Publication Date: 2017-11-21
XIDIAN UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, although many adjustable absorbers can realize the dynamic adjustment of the absorbing frequency, there are few adjustable absorbers that focus on converting broadband absorbing into narrowband absorbing, taking into account the working bandwidth conversion effect and absorbing performance, their tunable results are not entirely satisfactory
For example, in 2014, Yin Zhang et al. published "Graphene Based Tunable Metamaterial Absorber and Polarization Modulation in Terahertz Frequency" in the Journal of the Optical Society of America (2014,22(19):22743.). The method of combining double-layer graphene strips realizes the design of continuously adjustable terahertz absorbing frequency, but the working bandwidth of the absorber is not adjustable and its overall absorbing bandwidth is relatively narrow
In 2015, GangYao et al. published "Dynamically Electrically Tunable Broadband Absorber Based on Graphene Analog of Electromagnetically Induced Transparency" in IEEE Photonics Journal (2015,8(1):1-8.). (GPIT) metamaterial structure, using the special mechanism of the structure to realize the function of terahertz broadband absorption and tunable working bandwidth, but the absorber is adjusted from the broadband 0.5THz, the absorption rate is 80%, to the narrowband 0.3THz , the absorption rate is 70%, the bandwidth change is not obvious and the corresponding absorption effect within the working bandwidth is not good enough
[0004] With the increasing application of active adjustable wave absorbers in modern communications, it is required to be more adaptable to environmental changes and have all-round performance adjustable features, while the existing technology is used for The absorbing structure that realizes the active tuning of the absorbing rate is not flexible and stable enough; on the other hand, there are few structures used to realize the adjustable absorbing bandwidth and the tuning effect is not good, and at the same time, it lacks the perfect absorbing effect of the absorber itself

Method used

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  • Grapheme and ultra surface based working bandwidth adjustable wave absorber
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  • Grapheme and ultra surface based working bandwidth adjustable wave absorber

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Embodiment 1

[0018] The increasingly widespread application of tunable absorbers in modern communications makes it an urgent need to design absorbers with adjustable performance in many aspects. However, the absorbers designed in the prior art are not flexible enough to be tuned stably; There are few absorbing structures for adjustable bandwidth and the tuning effect is not good, and the absorbing effect in the working bandwidth is not perfect.

[0019] Aiming at the defects of the prior art, the present invention proposes a kind of working bandwidth adjustable wave absorber based on graphene and metasurface through experiments and researches. The present invention includes a DC power supply 1 and a frequency selective surface 3 stacked sequentially from top to bottom, The dielectric substrate 4 and the metal base plate 2, the frequency selective surface 3 is a metal surface structure arranged periodically, see figure 1 , the dielectric substrate 4 of the present invention is a three-layer...

Embodiment 2

[0022] The overall composition and specific structure of the adjustable wave absorber based on graphene and metasurfaces are the same as in Embodiment 1, see figure 2 , the metal patch 31 that is provided with graphene film 32 interlayers among the present invention, concrete structure is two completely identical metal narrow bands, and the middle is graphene film 32, and graphene film 32 width w 3 is the metal narrow band width w 1 2 times to 5 times that of graphene film 32 length l 3 and the metal strip length l 1 equal, the length l of the metal strip 1 with vertical metal wire 33 length l 2 In comparison, the so-called comparison refers to being equal or approximately equal in value, and ensuring that the error is controlled within a certain range when approximately equal. In this example, the length l of the narrow metal strip is controlled 1 with vertical metal wire 33 length l 2 The error between them is within ±0.2mm.

[0023] The width (w) of graphene film 32...

Embodiment 3

[0026] The overall composition and specific structure of the wave absorber with adjustable operating bandwidth based on graphene and metasurfaces are the same as in Embodiment 1-2. The electrical conductivity of the metal bottom plate 2 of the present invention is higher than that of ordinary metals, and the metal electrical conductivity σ and skin The relationship expression between depth δ is:

[0027]

[0028] Among them, f is the working frequency, μ is the magnetic permeability, σ is the electrical conductivity, and δ is the skin depth. It can be seen from formula (1) that the greater the conductivity, the smaller the corresponding skin depth, and the smaller the skin depth, most of the energy of the electromagnetic wave will be concentrated in the thin layer of the metal surface, that is, it has a good shielding effect on the electromagnetic wave .

[0029] In this example, the electrical conductivity of the metal base plate 2 is σ=4.1×10 7 S / m, higher than the cond...

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Abstract

The invention discloses a grapheme and ultra surface based working bandwidth adjustable wave absorber and mainly solves technical problems of non-adjustable bandwidth and poor wave absorbing performance of a prior wave absorber. The working bandwidth adjustable wave absorber provided by the invention includes a DC power source, and a frequency selecting surface, a three-layer dielectric substrate and a metal substrate arranged from top down in a successively overlapping manner. Air medium is arranged between the second dielectric layer, so that the wave absorbing bandwidth is expanded. The frequency selecting surface is composed of m*n dumb-bell shaped cycle units. Each of the upper end and the lower end of each dumb-bell shaped unit is provided with metal pasters connected by vertical metal leads and provided with grapheme film sandwich layers. A horizontal metal fine lead penetrates through each whole line of the dumb-bell shaped unit and achieves the serial connection of the dumb-bell shaped units. The working bandwidth adjustable wave absorber provided by the invention is simple in structure. By using the metal pasters provided with the grapheme film sandwich layers, the wave absorbing performance is good, so that the wave absorbing bandwidth can be tuned more conveniently. By adopting the metal substrate with high electricity conductivity, electromagnetic wave transmission of the wave absorber is reduced. The working bandwidth adjustable wave absorber provided by the invention is suitable for electromagnetic immunity and modern communication systems.

Description

technical field [0001] The invention belongs to the technical field of wave-absorbing materials, and mainly relates to wave absorbers with adjustable bandwidth, in particular to a wave absorber with adjustable working bandwidth based on graphene and metasurfaces, which can be used in electromagnetic anti-interference and modern communication systems. Background technique [0002] Graphene is a two-dimensional structure composed of carbon atoms. It has many excellent properties, such as the thinnest material, the hardest material, extremely high carrier mobility, flexibility and light transmission, and electrical conductivity can pass through The external electric field and magnetic field are adjusted, etc. These excellent properties can be used to design various new nano-devices or transparent conductive materials, such as transparent electrodes, optical modulators, polarizers, plasmonic devices, photon detectors, superprisms and wave-absorbing devices. , A new material wit...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01Q15/00H01Q17/00H05K9/00
CPCH01Q15/0013H01Q17/00H01Q17/008H05K9/00
Inventor 吴边李慧玲赵雨桐张伟贺连星
Owner XIDIAN UNIV
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