A three-dimensional honeycomb structure based on resistive film broadband metamaterial wave absorber

Abstract

The application discloses a wide-band metamaterial wave absorber based on a three-dimensional honeycomb structure of a resistance film, which comprises a three-dimensional honeycomb structure medium layer, a resistance film layer and a metal back plate, wherein the inner surface of the three-dimensional honeycomb structure medium layer is coated with the resistance film layer, and the metal back plate is arranged on one side of the three-dimensional honeycomb structure medium layer; the basic unit of the three-dimensional honeycomb structure medium layer is a parallelogram structure which is composed of two equilateral triangles; and the resistance film layer is in a honeycomb shape, and the resistance value of the resistance film layer is 370-450 ohms. The wave absorber has a simple structure, the thickness of the metal layer is ignored, and the total thickness of the structure is only 5.5 mm. After the structural units are arranged in cycles, the structure is multiple-symmetrical and has polarization stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metamaterial absorber, and particularly relates to a wideband metamaterial absorber based on a three-dimensional honeycomb structure of a resistive film. BACKGROUND

[0002] The statements herein are provided only to further provide context of the present application and are not necessarily prior art.

[0003] Absorbing materials are materials that can absorb incident electromagnetic wave energy and convert it into heat or other forms of energy. In the field of civil use, absorbing materials can be used to eliminate or reduce electromagnetic radiation pollution, reduce electromagnetic interference, and improve the electromagnetic compatibility of equipment.

[0004] Metamaterials have become a research hotspot in the field of absorbing materials due to their ability to finely control the polarization state, phase, wave state, and wave vector of electromagnetic waves. It is a class of materials that are artificially designed to achieve physical properties that natural materials do not possess. Unlike traditional absorbing materials, metamaterials achieve effective electromagnetic wave absorption by adjusting the structure size to achieve adjustable electromagnetic parameters. Metamaterial absorbing structures have the advantages of thin thickness, good absorption effect, and light weight.

[0005] The earliest metamaterial absorber was designed by Landy in 2008. The structure of the absorber uses electromagnetic resonance to achieve perfect absorption at 11.5 GHz, and the size of the structure unit and the distance between the upper and lower metal layers can be adjusted to control the absorption frequency within a certain range. However, it has the defects of polarization sensitivity, incident angle sensitivity, and narrow absorption bandwidth.

[0006] Currently, there has been great progress in the research of wideband metamaterial absorbers, but there are still problems such as thick structure, polarization sensitivity, and complex design patterns that are difficult to process for radar waveband absorber structures. SUMMARY

[0007] In view of the deficiencies of the prior art, the present application aims to provide a wideband metamaterial absorber based on a three-dimensional honeycomb structure of a resistive film.

[0008] In order to achieve the above-mentioned purpose, the present application is realized by the following technical scheme:

[0009] A wideband metamaterial absorber based on a three-dimensional honeycomb structure of a resistive film, comprising a three-dimensional honeycomb structure dielectric layer, a resistive film layer, and a metal back plate, wherein,

[0010] The inner surface of the three-dimensional honeycomb structure dielectric layer is coated with the resistive film layer, and one side of the three-dimensional honeycomb structure dielectric layer is provided with the metal back plate;

[0011] The basic unit of the three-dimensional honeycomb structure dielectric layer is a parallelogram structure composed of two equilateral triangles.

[0012] The resistance film layer is in a honeycomb shape, and the resistance value is 370-450Ω.

[0013] In the design of metamaterial absorbers, the multi-layer stacking mode and the three-dimensional structure both have the effect of widening the absorption bandwidth, and the three-dimensional structure has the characteristics of light weight, but in practical application, the problem of structural strength also needs to be considered. Through experiments, it is found that the hexagonal honeycomb structure has the advantages of high strength and high proportion of the middle part, and is easy to realize light weight, etc. Therefore, the three-dimensional honeycomb structure is selected.

[0014] In addition, the change of the resistance value of the resistance film mainly affects the performance of low frequency. With the continuous increase of the resistance value of the resistance film, the absorption rate at low frequency is continuously increased. The change of the resistance value of the resistance film has little effect on the absorption effect of frequencies above 30GHz, and the absorption rate basically does not change. When the resistance value is greater than 370Ω, effective absorption of 7-300GHz can be realized, but when the resistance value continues to increase and exceeds 450Ω, although the low-frequency absorption rate will increase, the absorption bandwidth will gradually decrease. The thickness of the resistance film is determined by the resistance value during processing, and the material is generally conductive graphite, indium tin oxide, etc.

[0015] In some embodiments, the height of the three-dimensional honeycomb structure dielectric layer is 4-5.5mm.

[0016] The length of the parallelogram is 3.49mm.

[0017] In some embodiments, the dielectric layer adopts Arlon AD 250C.

[0018] Preferably, the relative dielectric constant ε r of the dielectric layer is 2.5, and the loss tangent is 0.0013.

[0019] Preferably, the wall thickness of the three-dimensional honeycomb structure dielectric layer is 0.07-0.1mm.

[0020] In some embodiments, the material of the metal back plate is copper.

[0021] Preferably, the electrical conductivity of the metal back plate is 5.75×10 7 -6×10 7 S / m.

[0022] Preferably, the thickness of the metal back plate is 0.01-0.02mm.

[0023] In some embodiments, the resistance film is prepared by a screen printing process.

[0024] The beneficial effects achieved by one or more embodiments of the above-mentioned application are as follows:

[0025] The structure of the wave absorber of the present application adopts a hexagonal honeycomb structure as a main structure, and a resistance film is coated in the structure, thereby realizing effective absorption of electromagnetic waves in the range of 7GHz-300GHz while ensuring the structural strength, the relative wave absorption bandwidth is 190.8%, and the absorption rate of most frequency bands is more than 95%, which basically covers the radar wave band. The problems of thick structure, polarization sensitivity and complex structure difficult to process of the metamaterial wave absorber structure are solved.

[0026] The wave absorber of the present application has a simple structure, and the total thickness of the structure is only 5.5mm when the thickness of the metal layer is ignored. The structure unit is arranged in a multiple symmetry and has polarization stability. BRIEF DESCRIPTION OF DRAWINGS

[0027] The drawings accompanying the specification of the present application serve to provide further understanding of the present application, and the schematic embodiments of the present application and the description thereof serve to explain the present application, and do not constitute an improper limitation on the present application.

[0028] Figure 1 It is a schematic diagram of a wideband metamaterial wave absorber structure based on a three-dimensional honeycomb structure of a resistance film; wherein (a) is an elevation view; (b) is a structure unit exploded view; (c) is a periodic arrangement mode;

[0029] Figure 2 It is a simulation calculation result of normal incidence absorption rate and reflection coefficient of a wideband metamaterial wave absorber structure based on a three-dimensional honeycomb structure of a resistance film.

[0030] 1, metal back plate; 2, three-dimensional honeycomb structure dielectric layer; 3, resistance film layer. DETAILED DESCRIPTION

[0031] It should be pointed out that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0032] Example 1

[0033] As shown in Figure 1 , the wave absorber structure includes a three-dimensional honeycomb structure dielectric layer, a resistance film layer and a metal back plate. The structure unit of the wave absorber is a parallelogram structure composed of two equilateral triangle structures, the bottom of the structure has a metal back plate, the equilateral triangle structure is a dielectric layer, and the equilateral triangle structure is coated with a resistance film layer. The dielectric layer adopts Arlon AD250C, the relative dielectric constant ε r =2.5, the loss tangent tanθ=0.0013, the parallelogram side length a=b=3.49mm, the metal back plate adopts copper, and the conductivity σ=5.96×107 S / m, thickness of 0.018 mm. The thickness of the dielectric layer h1=0.1 mm, the height of the dielectric layer h2=5.5 mm. The resistance of the resistance film is Z=370 Ω.

[0034] Considering the structure size and the requirement of calculation accuracy, the frequency domain solver of CST simulation software is used for simulation calculation, the x, y directions are set as unit cell periodic boundary conditions, but when arranged, the x, y directions are periodically arranged at a certain angle to form a hexagonal honeycomb structure. The positive direction of the Z axis is an open condition, simulating the open boundary of free space, and the electromagnetic wave excitation is vertically incident on the model surface from the positive direction of the Z axis. Because the metal back plate blocks the passage of electromagnetic waves, in order to reduce the amount of calculation, the negative direction of the Z axis and the metal back plate are set as electric boundary (electric (Et=0)), and the structure is multiply symmetric after periodic arrangement, so only the case of TE mode electromagnetic wave incidence is discussed in the simulation calculation. The calculation results of S parameter and absorption rate curve are as shown in Figure 2 , realizing more than 90% effective absorption of 7-300 GHz. The relative wave absorption bandwidth is 190.8%, and the absorption rate reaches more than 95% in the frequency bands of 8.68-10.24 GHz and 32.39-300 GHz, basically covering the radar wave band.

[0035] Embodiment 2

[0036] As shown in Figure 1 , the wave-absorbing body structure includes a three-dimensional honeycomb structure dielectric layer, a resistance film layer and a metal back plate. The structural unit of the wave-absorbing body is a parallelogram structure composed of two equilateral triangle structures, and the bottom of the structure has a metal back plate. The equilateral triangle structure is a dielectric layer, and the equilateral triangle structure is coated with a resistance film layer. The dielectric layer adopts Arlon AD250C, the relative dielectric constant ε r =2.5, the loss tangent tanθ=0.0013, the length of the parallelogram a=b=3.49 mm, and the metal back plate adopts copper, and the conductivity σ=5.96×10 7 S / m, thickness of 0.018 mm. The thickness of the dielectric layer h1=0.07 mm, the structure height h2=5.5 mm. The resistance of the resistance film is Z=370 Ω.

[0037] Considering the structure size and the requirement of calculation accuracy, the CST simulation software frequency domain solver simulation calculation is used, the x, y direction is set as unit cell periodic boundary condition, but when arranging, the x, y direction is arranged periodically at a certain angle, forming a hexagonal honeycomb structure. The positive direction of Z axis is open condition, simulating the open boundary of free space, and the electromagnetic wave excitation is vertically incident to the model surface from the positive direction of Z axis. Because the metal back plate resists the passing of electromagnetic wave, in order to reduce the calculation amount, the negative direction of Z axis and the metal back plate are set as electric boundary (electric (Et=0)). After periodic arrangement, the structure is multiple symmetric, so only the case of TE mode electromagnetic wave incidence is discussed in the simulation calculation. More than 90% of 7-300GHz is effectively absorbed. The relative wave absorption bandwidth is 190.8%, and the absorption rate reaches more than 95% in the frequency bands of 33.53-169.73GHz, 177.23-189.91GHz, 201.51-213.29GHz, 225.01-237.63GHz, 246.06-300GHz, basically covering the radar wave band.

[0038] Example 3

[0039] As Figure 1 shown, the wave-absorbing body structure includes a three-dimensional honeycomb structure dielectric layer, a resistance film layer and a metal back plate. The structural unit of the wave-absorbing body is a parallelogram structure composed of two equilateral triangle structures, the bottom of the structure has a metal back plate, the equilateral triangle structure is a dielectric layer, and the equilateral triangle structure is coated with a resistance film layer. The dielectric layer adopts Arlon AD250C, the relative dielectric constant ε r =2.5, the loss tangent tanθ=0.0013, the parallelogram side length a=b=3.49mm, the metal back plate adopts copper, the conductivity σ=5.96×10 7 S / m, and the thickness is 0.018mm. The dielectric layer thickness h1=0.1mm, and the structure height h2=4mm. The resistance of the resistance film is Z=370Ω.

[0040] Considering the structure size and the requirement of calculation accuracy, the CST simulation software frequency domain solver simulation calculation is used, the x, y direction is set as unit cell periodic boundary condition, but when arranging, the x, y direction is periodically arranged at a certain angle, forming a hexagonal honeycomb structure. The positive direction of Z axis is open condition, simulating the open boundary of free space, and the electromagnetic wave excitation is vertically incident to the model surface from the positive direction of Z axis. Because the metal back plate resists the passing of electromagnetic wave, in order to reduce the calculation amount, the negative direction of Z axis and the metal back plate are set as electric boundary (electric (Et=0)). After periodic arrangement, the structure is multiple symmetry, so only the case of TE mode electromagnetic wave incidence is discussed in the simulation calculation. More than 90% of 7-300GHz is effectively absorbed. The relative wave absorption bandwidth is 190.8%, and the absorption rate reaches more than 95% in the frequency bands of 12.43-25.28GHz, 44.16-155.37GHz, 165.95-183.19GHz, 195.85-216.52GHz and 221.91-30GHz, basically covering the radar wave band.

[0041] Example 4

[0042] As shown in Figure 1 , the wave absorbing body structure includes a three-dimensional honeycomb structure dielectric layer, a resistance film layer and a metal back plate. The structural unit of the wave absorbing body is a parallelogram structure composed of two equilateral triangle structures, the bottom of the structure has a metal back plate, the equilateral triangle structure is a dielectric layer, and the equilateral triangle structure is coated with a resistance film layer. The dielectric layer adopts Arlon AD250C, the relative dielectric constant ε r =2.5, the loss tangent tanθ=0.0013, the parallelogram side length a=b=3.49mm, the metal back plate adopts copper, the conductivity σ=5.96×10 7 S / m, and the thickness is 0.018mm. The dielectric layer thickness h1=0.1mm, and the structure height h2=5.5mm. The resistance of the resistance film is Z=450Ω.

[0043] Considering the structure size and the requirement of calculation accuracy, the frequency domain solver of CST simulation software is used for simulation calculation, the x and y directions are set as unit cell periodic boundary conditions, but the x and y directions are arranged at a certain angle and periodically arranged to form a hexagonal honeycomb structure. The positive direction of the Z axis is an open condition, simulating the open boundary of free space, and the electromagnetic wave excitation is vertically incident on the model surface from the positive direction of the Z axis. Because the metal back plate blocks the electromagnetic wave, in order to reduce the calculation amount, the negative direction of the Z axis and the metal back plate are set as electric boundary (electric (Et=0)), and the structure is multiple symmetrical after periodic arrangement, so only the case of TE mode electromagnetic wave incidence is discussed in the simulation calculation. More than 90% of the effective absorption of 7-300GHz is realized. The relative wave absorption bandwidth is 190.8%, and the absorption rate reaches more than 95% in the frequency bands of 8.51-15.12GHz and 31.81-300GHz, basically covering the radar wave band.

[0044] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A wideband metamaterial absorber based on three-dimensional honeycomb structure of resistive film, characterized in that: It comprises a three-dimensional honeycomb structure medium layer, a resistance film layer and a metal back plate, wherein, The inner surface of the three-dimensional honeycomb structure medium layer is coated with the resistance film layer, and one side of the three-dimensional honeycomb structure medium layer is provided with the metal back plate; The basic unit of the three-dimensional honeycomb structure medium layer is a parallelogram structure composed of two equilateral triangles; the equilateral triangle is coated with the resistance film layer; the height of the three-dimensional honeycomb structure medium layer is 4-5.5 mm; the resistance film layer is honeycomb-shaped, and the resistance value is 370-450 Ω.

2. The resistive film based three-dimensional honeycomb structure wideband metamaterial absorber of claim 1, wherein: The length of the side of the parallelogram is 3.49 mm.

3. The resistive film based three-dimensional honeycomb structure wideband metamaterial absorber of claim 1, wherein: The medium layer adopts Arlon AD 250C.

4. The resistive film based three-dimensional honeycomb structure wideband metamaterial absorber of claim 3, wherein: The relative dielectric constant ε of the dielectric layer r was 2.5, and the loss tangent was 0.0013.

5. The resistive film based three-dimensional honeycomb structure wideband metamaterial absorber of claim 1, wherein: The wall thickness of the three-dimensional honeycomb structure medium layer is 0.07-0.1 mm.

6. The resistive film-based three-dimensional honeycomb-structured broadband metamaterial absorber of claim 1, wherein: The material of the metal back plate is copper.

7. The resistive film-based three-dimensional honeycomb-structured broadband metamaterial absorber of claim 6, wherein: The metal backsheet has an electrical conductivity of 5.75 x 10 7 -6 x 10 7 S / m.

8. The resistive film-based three-dimensional honeycomb-structured broadband metamaterial absorber of claim 1, wherein: The thickness of the metal back plate is 0.01-0.02 mm.

9. The resistive film-based three-dimensional honeycomb-structured broadband metamaterial absorber of claim 1, wherein: The resistance film is prepared by a screen printing process.

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