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Flexible multilayer wave-absorbing material with adjustable frequency band and preparation method thereof

A wave-absorbing material and flexible technology, applied in antennas, electrical components, magnetic field/electric field shielding, etc., can solve the problems of narrow wave-absorbing frequency band, heavy metal plate weight, poor impedance matching, etc., and achieve broadband high-strength absorption and good air permeability , the effect of improving work efficiency

Active Publication Date: 2021-03-02
THE QUARTERMASTER RES INST OF THE GENERAL LOGISTICS DEPT OF THE CPLA +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] A single absorbing material often has the disadvantages of poor impedance matching, limited absorption performance, and narrow absorbing frequency band.
Multi-layer composite absorbing material is an important means to achieve high-strength and broadband absorption. Patent application (CN 106469858A) discloses a absorber structure, which is multi-layered with metal plates, honeycomb layers, and resistor sheets to obtain broadband, Strong absorbing wave-absorbing material, but the weight of the metal plate is heavy, and the total thickness of the composite material exceeds 20cm. Patent application (CN10983029A) discloses a wave-absorbing composite material and its preparation method, specifically impedance matching layer / three-dimensional graphene layer / The preparation method of the low-frequency electromagnetic loss layer has a wide absorbing frequency band at low frequencies; the patent application (CN 108092006 A) discloses a layered broadband radar absorbing sheet and its preparation method, and the patent application (CN 105744816 B) discloses an electromagnetic wave Shielding composite film, the above two patent applications disclose the preparation method of multi-layer wave-absorbing film, the layer composite materials in the above patents can improve the absorption of electromagnetic waves, but cannot realize the selective transmission of electromagnetic waves in a specific frequency band However, it does not have the unique softness and breathability of fabrics
[0005] At present, there is a lack of multi-layer composite materials that can efficiently control the absorbing frequency band of absorbing materials and meet the needs of absorbing materials with soft and breathable properties.

Method used

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  • Flexible multilayer wave-absorbing material with adjustable frequency band and preparation method thereof
  • Flexible multilayer wave-absorbing material with adjustable frequency band and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0045] Embodiment 1, double-layer composite wave-absorbing fabric

[0046] Select the shape of the FSF resonant unit as a cross, the distance between the resonant units is 30mm, and the resonant frequency is 3.96GHz. Use screen printing to apply conductive silver paste on the polyester woven fabric according to the periodic arrangement and size of the simulation design to make a patch type FSF ,Such as figure 1 As shown; mix barium titanate and water-based polyurethane according to the mass ratio of 3:1, mechanically stir for 5 minutes, mix evenly, and then scrape and coat on cotton woven fabrics as wave-absorbing fabrics, with an area density of 625g / m 2 . According to the frequency, the fabric is selected on the top, and the wave-absorbing fabric is laminated on the bottom to obtain a double-layer composite wave-absorbing fabric with a thickness of 0.66mm.

[0047]In the 2-18GHz test range, the peak reflectivity is -17.3dB, the bandwidth less than -5dB is 9.4GHz, and the ...

Embodiment 2

[0048] Embodiment 2, three-layer wave-absorbing fabric

[0049] Select the shape of the FSF resonant unit to be U-shaped, the distance between the resonant units to be 20mm, and the resonant frequency to be 4.78GHz. Use screen printing to apply conductive copper paste on the cotton knitted fabric according to the periodic arrangement and size of the simulated design to make a patch type FSF ,Such as figure 1 Shown; mix zinc oxide and polyvinyl alcohol (molecular weight: 1000) according to the mass ratio of 1:1, mechanically stir for 5 minutes, after mixing evenly, soak the polyester three-dimensional spacer fabric in it for 15 minutes, and dry it at room temperature as a wave-absorbing fabric. 714g / m 2 . Copper-nickel mixed slurry was coated on polyester knitted fabric by electroless plating as electromagnetic wave reflective fabric. According to the order of the absorbing layer on the top, the FSF in the middle, and the electromagnetic wave reflecting fabric on the bottom...

Embodiment 3

[0051] Embodiment 3, three-layer wave-absorbing fabric

[0052] The shape of the FSF resonant unit is selected as a circular ring, the distance between the resonant units is 20mm, and the resonance frequency is 6GHz. The conductive copper paste is coated on the polyester woven fabric by screen printing, and then according to the periodic arrangement and size of the simulated design, the laser is used to Burning and tearing off the resonant unit part to make a pore-type FSF, such as figure 1 Shown; mix graphite and oily polyurethane according to the mass ratio of 11:20, stir mechanically for 5 minutes, soak the polyester three-dimensional spacer fabric in it for 20 minutes after mixing evenly, dry at room temperature as the wave-absorbing layer, and the surface density is 1250g / m 2 . Silver yarn is used as raw material to weave woven fabric as electromagnetic wave reflective fabric. Then, the three-layer wave-absorbing fabric was obtained by stacking in the order of FSF on t...

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Abstract

The invention discloses a flexible multilayer wave-absorbing material with an adjustable frequency band and a preparation method thereof. The flexible multilayer wave-absorbing material is the following 1) or 2): 1) a double-layer wave-absorbing material formed by stacking a wave-absorbing fabric layer and a frequency selection fabric layer or an electromagnetic wave reflection fabric layer according to any sequence; 2) a multilayer wave-absorbing material formed by stacking a frequency selection fabric layer, a wave-absorbing fabric layer and an electromagnetic wave reflection fabric layer according to any sequence, wherein the frequency selection fabric layer is made of a frequency selection fabric, and the frequency selection fabric is a fabric with designable resonance frequency points; the wave-absorbing fabric layer is made of wave-absorbing fabric, and the wave-absorbing fabric is fabric containing a wave-absorbing agent. Through analogue simulation, the periodic arrangement andsizes of the FSF units required by different frequency bands are efficiently designed, the FSF units with the filtering function, the wave absorbing fabric and the electromagnetic wave reflecting fabric are laminated according to different stacking sequences and layer combinations, the layer composite material can be regulated and controlled to realize broadband high-strength absorption in different working frequency bands, and the working efficiency is improved.

Description

technical field [0001] The invention relates to a flexible multi-layer microwave-absorbing material with adjustable frequency band and a preparation method thereof, belonging to the technical field of microwave-absorbing materials. Background technique [0002] The absorbing material needs to meet two conditions. One is that the impedance of the material and free space is as equal as possible, and the other is that it has a high electromagnetic wave loss capability, so as to convert electromagnetic wave energy into heat energy or other forms of energy to the greatest extent, without being like electromagnetic shielding. Materials produce secondary pollution. Commonly used absorbing agents are carbonyl iron, ferrite and so on. For example, carbonyl iron is a high-permeability absorbing material that relies on hysteresis loss and eddy current loss to attenuate electromagnetic waves. However, in order to achieve the absorption effect, it is often accompanied by problems such a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01Q15/00H01Q17/00H05K9/00
CPCH01Q15/0026H01Q15/0046H01Q17/005H05K9/0088
Inventor 张恒宇肖红陈剑英王焰梁高勇冯硕季惠孟令卿施楣梧
Owner THE QUARTERMASTER RES INST OF THE GENERAL LOGISTICS DEPT OF THE CPLA