Wave-absorbing structure and wave-absorbing material

Abstract

The invention discloses a wave-absorbing structure and a wave-absorbing material. The wave-absorbing structure comprises a dielectric layer, a first resistance layer and a substrate layer which are sequentially stacked from top to bottom, the dielectric layer comprises a first sub-dielectric layer and a second sub-dielectric layer which are stacked from top to bottom, a mounting hole is formed in the first sub-dielectric layer, a second resistance layer is arranged in the mounting hole, and the upper surface of the second resistance layer is an incident surface of electromagnetic waves. The dielectric layer, the first resistive layer and the substrate layer are sequentially stacked from top to bottom to form a multi-layer composite wave-absorbing structure, so that electromagnetic waves are subjected to multiple times of interference among the second resistive layer, the dielectric layer and the first resistive layer after being incident from the second resistive layer, and are consumed through the absorption and reflection effects of the resistive layers and the substrate layer; and meanwhile, the dielectric layer is used for compensating the impedance of the wave absorbing structure, so that a wider wave absorbing bandwidth in an oblique incidence state of electromagnetic waves is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic wave absorbing materials, and in particular to a wave absorbing structure and a wave absorbing material. Background Art

[0002] Absorbing materials are functional materials that can absorb electromagnetic waves and dissipate electromagnetic energy. They can convert electromagnetic wave energy into heat or other forms of energy and dissipate it. However, current research on the performance of absorbing materials usually focuses on low reflectivity, which makes it difficult to effectively consume the energy of electromagnetic waves during multiple reflections and transmissions, resulting in poor absorbing effects. In addition, when electromagnetic waves are incident at large angles, due to impedance mismatch, the performance of absorbing materials will significantly decrease, and the absorbing bandwidth will become narrower, which cannot meet the application requirements of broadband and efficient absorbing. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a wave absorbing structure and a wave absorbing material.

[0004] A first aspect of the present invention provides an absorbing structure, comprising a dielectric layer, a first resistor layer and a substrate layer stacked in sequence from top to bottom;

[0005] The dielectric layer comprises a first sub-dielectric layer and a second sub-dielectric layer stacked from top to bottom, a mounting hole is provided on the first sub-dielectric layer, a second resistance layer is arranged in the mounting hole, and an upper surface of the second resistance layer is an incident surface of electromagnetic waves.

[0006] In some embodiments of the present invention, the surface resistance of the first resistance layer is 10-100Ω / □, and the surface resistance of the second resistance layer is 50-250Ω / □.

[0007] In some embodiments of the present invention, the inner diameter of the first sub-dielectric layer is smaller than the inner diameter of the second sub-dielectric layer, the projection of the first sub-dielectric layer on the horizontal plane is a square with a side length of 0.1-10 mm, and the cross-section of the second sub-dielectric layer is a square with a side length of 5-15 mm;

[0008] The thickness of the second resistance layer, the thickness of the first sub-dielectric layer and the depth of the mounting hole are the same, both of which are 0.1-1.5 mm;

[0009] The thickness of the first resistance layer is 0.1-0.5 mm.

[0010] In some embodiments of the present invention, the relative dielectric constant of the dielectric layer is 1.0-5.0, and the thickness of the dielectric layer is 0.2-10 mm.

[0011] In some embodiments of the present invention, the second resistor layer is formed by filling the mounting hole with a conductive paste by mechanical injection;

[0012] The first resistance layer is formed by printing the conductive paste on the lower surface of the dielectric layer or the upper surface of the substrate layer by screen printing.

[0013] In some embodiments of the present invention, the projection shapes of the second sub-dielectric layer, the first resistance layer and the substrate layer on the horizontal plane are the same, and are all squares with a side length of 5-15 mm.

[0014] In some embodiments of the present invention, the material of the dielectric layer includes one or more of quartz fiber, basalt fiber, glass fiber, high boron fiber, cyanate resin, epoxy resin, polyimide, and polymethyl methacrylate;

[0015] The material of the first resistance layer includes one or more of carbon nanotubes, graphene, carbon nanoparticles, carbon fibers, silver nanowires, zinc oxide, zinc tin oxide, and indium tin oxide;

[0016] The material of the second resistance layer includes one or more of carbon nanotubes, graphene, carbon nanoparticles, carbon fibers, silver nanowires, zinc oxide, zinc tin oxide, and indium tin oxide.

[0017] In some embodiments of the present invention, the substrate layer includes a plurality of first lining layer units and second lining layer units which are alternately stacked in sequence;

[0018] The first lining layer unit and the second lining layer unit are both made of carbon fiber fabric composite materials, and the first lining layer unit and the second lining layer unit are prepared by an autoclave molding process to form the substrate layer.

[0019] In some embodiments of the present invention, the first lining layer unit includes a first carbon fiber reinforcement and a first resin matrix, and the first carbon fiber reinforcement is disposed in the first resin matrix;

[0020] The second lining layer unit comprises a second carbon fiber reinforcement and a second resin matrix, and the second carbon fiber reinforcement is penetrated in the second resin matrix;

[0021] The angle between the first carbon fiber reinforcement in the adjacent first lining layer unit and the second carbon fiber reinforcement in the second lining layer unit in the ply direction is 45°.

[0022] The second aspect of the present invention further provides an absorbing material, which comprises M×N absorbing structures as described in any one of the first aspects above, wherein each of the absorbing structures is arranged in an M×N rectangular periodic pattern in a two-dimensional plane, wherein M>10, N>10.

[0023] The wave absorbing structure and wave absorbing material provided by the present invention have at least the following advantages:

[0024] The wave absorbing structure provided by the present invention forms a multi-layer composite wave absorbing structure by stacking a dielectric layer, a first resistor layer and a substrate layer in sequence from top to bottom, so that after the electromagnetic wave is incident from the second resistor layer, multiple interferences occur between the second resistor layer, the dielectric layer and the first resistor layer, and the electromagnetic wave is consumed by absorption and reflection of the resistor layer and the substrate layer, thereby improving the overall wave absorbing efficiency. At the same time, the dielectric layer is used to compensate the impedance of the wave absorbing structure, thereby achieving a wider wave absorbing bandwidth under the oblique incidence state of the electromagnetic wave. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 A schematic diagram of an explosion structure of a wave absorbing structure provided by an exemplary embodiment of the present invention;

[0027] Figure 2 A schematic structural diagram of a wave absorbing structure provided by an exemplary embodiment of the present invention;

[0028] Figure 3 A schematic diagram of a top view of a wave absorbing structure provided by an exemplary embodiment of the present invention;

[0029] Figure 4 A schematic structural diagram of a substrate layer provided for an exemplary embodiment of the present invention;

[0030] Figure 5 A schematic diagram of the structure of an absorbing material provided by an exemplary embodiment of the present invention;

[0031] Figure 6 A graph showing the variation of reflectivity with frequency when an electromagnetic wave is incident at a vertical angle, provided for an exemplary embodiment of the present invention;

[0032] Figure 7 A diagram showing how the absorption performance of electromagnetic waves varies with frequency at different incident angles, provided for an exemplary embodiment of the present invention.

[0033] The following are marked in the accompanying drawings:

[0034] 1. dielectric layer; 110. first sub-dielectric layer; 111. mounting hole; 120. second sub-dielectric layer;

[0035] 2. The first resistance layer;

[0036] 3. substrate layer; 310. first lining layer unit; 311. first carbon fiber reinforcement; 312. first resin matrix; 320. second lining layer unit; 321. second carbon fiber reinforcement; 322. second resin matrix;

[0037] 4. The second resistance layer. DETAILED DESCRIPTION

[0038] The technical scheme in the embodiment of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the present invention.

[0039] Reference to an "embodiment" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0040] Nowadays, the problem of electromagnetic radiation pollution is no longer limited to the stealth technology of military equipment. The electromagnetic interference it causes can also lead to signal disconnection, attenuation and other failures in industrial and civilian equipment, and even cause serious damage to the human body exposed to strong electromagnetic radiation for a long time. Therefore, the technology to weaken or even eliminate electromagnetic radiation has become a hot issue of concern to society and the scientific community.

[0041] Absorbing materials are functional materials that can absorb electromagnetic waves and dissipate electromagnetic energy. They can convert electromagnetic wave energy into heat or other forms of energy and dissipate it. However, current research on the performance of absorbing materials usually focuses on low reflectivity, which makes it difficult to effectively consume the energy of electromagnetic waves during multiple reflections and transmissions, resulting in poor absorbing effects. In addition, when electromagnetic waves are incident at large angles, due to impedance mismatch, the performance of absorbing materials will significantly decrease, and the absorbing bandwidth will become narrower, which cannot meet the application requirements of broadband and efficient absorbing.

[0042] Combine the following Figure 1-Figure 7 The embodiments of the present invention are further described.

[0043] In order to solve the above technical problems, the present invention provides an absorbing structure and an absorbing material, wherein a multi-layer composite absorbing structure is formed by stacking a dielectric layer, a first resistor layer and a substrate layer in sequence from top to bottom in the absorbing structure, so that after the electromagnetic wave is incident from the second resistor layer, multiple interferences occur between the second resistor layer, the dielectric layer and the first resistor layer, and the electromagnetic wave is consumed by absorption and reflection of the resistor layer and the substrate layer, thereby improving the overall absorbing efficiency. At the same time, the dielectric layer is used to compensate the impedance of the absorbing structure, thereby achieving a wider absorbing bandwidth under the oblique incidence state of the electromagnetic wave.

[0044] An exemplary embodiment of the present invention provides a wave absorbing structure, such as Figure 1 and Figure 2 As shown, it includes a dielectric layer 1, a first resistor layer 2 and a substrate layer 3 stacked in sequence from top to bottom; it can be understood that along the thickness direction of the absorbing structure, from the upper surface of the absorbing structure to the lower surface of the absorbing structure, the dielectric layer 1, the first resistor layer 2 and the substrate layer 3 are sequentially arranged, that is, the first resistor layer 2 is arranged on the upper surface of the substrate layer 3, and the dielectric layer 1 is arranged on the upper surface of the first resistor layer 2. It should be noted that the upper and lower here are only used for convenience of description and do not constitute a limitation on the absorbing structure. The dielectric layer 1 includes a first sub-dielectric layer 1101 and a second sub-dielectric layer 1201 stacked in sequence from top to bottom, wherein the first sub-dielectric layer 1101 and the second sub-dielectric layer 1201 can be a split structure or an integrally formed structure. The first sub-dielectric layer 1101 is provided with a mounting hole 111, and a second resistor layer 4 is provided in the mounting hole 111. The upper surface of the second resistor layer 4 is the incident surface of the electromagnetic wave, and the lower surface of the second resistor layer 4 is in contact with the upper surface of the second sub-dielectric layer 1201, wherein the dielectric layer 1 can be prepared and formed by a hot press molding process. Exemplarily, the second resistor layer 4 is set to be a circle that matches the mounting hole 111, and the circle has uniformity and symmetry, which facilitates the filling of the second resistor layer 4 into the dielectric layer 1. At the same time, the electromagnetic wave can be irradiated more evenly on the surface of the second resistor layer 4, thereby improving the reception efficiency of the electromagnetic wave, reducing the reflection and scattering of the electromagnetic wave on the surface of the resistor layer, and allowing more electromagnetic wave energy to be effectively absorbed by the second resistor layer 4. In this way, a multi-layer composite absorbing structure is formed by stacking the dielectric layer 1, the first resistor layer 2 and the substrate layer 3 in sequence from top to bottom, so that after the electromagnetic wave is incident from the second resistor layer 4, multiple interferences occur between the second resistor layer 4, the dielectric layer 1 and the first resistor layer 2, and the electromagnetic wave is consumed by the absorption and reflection of the resistor layer and the substrate layer 3, thereby improving the overall absorbing efficiency. At the same time, the impedance compensation of the absorbing structure by the dielectric layer 1 is used to achieve a wider absorbing bandwidth under the oblique incidence state of the electromagnetic wave.

[0045] In some embodiments of the present invention, reference Figure 1 , Figure 2 and Figure 3 , the surface resistance of the first resistance layer 2 is 10-100Ω / □, and the surface resistance of the second resistance layer 4 is 50-250Ω / □. After the electromagnetic wave enters the absorbing material, it will first consume the energy of the electromagnetic wave in the second resistance layer 4 and convert it into heat energy, and then the electromagnetic wave that is not consumed will be further consumed in the first resistance layer 2. This synergistic effect helps to improve the overall absorption efficiency. Resistance layers with different resistance values ​​can be optimized for electromagnetic waves of different frequencies, so that effective dissipation can be achieved in a wider frequency range.

[0046] In some embodiments of the present invention, reference Figure 1 , Figure 2 and Figure 3 , the inner diameter of the first sub-dielectric layer 1101 is smaller than the inner diameter of the second sub-dielectric layer 1201, the projection of the first sub-dielectric layer 1101 on the horizontal plane is a square with a side length of 0.1-10mm, and the cross-section of the second sub-dielectric layer 1201 is a square with a side length of 5-15mm; the thickness of the second resistance layer 4, the thickness of the first sub-dielectric layer 1101 and the hole depth of the mounting hole 111 are the same, all of which are 0.1-1.5mm; the thickness of the first resistance layer 2 is 0.1-0.5mm. For example, referring to Figure 2 and Figure 3 , the diameters of the second resistance layer 4 and the mounting hole 111 are the same, both of which are 5mm, the side length of the first sub-dielectric layer 1101 is 8mm, the side length of the second sub-dielectric layer 1201 is 10mm, the thickness of the second resistance layer 4, the thickness of the first sub-dielectric layer 1101 and the hole depth of the mounting hole 111 are all 1mm, the thickness of the second sub-dielectric layer 1201 is 5mm, and the thickness of the first resistance layer 2 is 0.2mm. When the inner diameter of the first sub-dielectric layer 1101 is smaller than the inner diameter of the second sub-dielectric layer 1201, this stepped structural design is more conducive to the absorption of electromagnetic waves, and dielectric layers 1 of different sizes can produce different responses to electromagnetic waves of different frequencies, thereby broadening the absorption band or improving the absorption efficiency. The difference in inner diameter can also affect the impedance matching between dielectric layers 1, which helps to reduce the reflection of electromagnetic waves and further improve the absorption performance.

[0047] In some embodiments of the present invention, reference Figure 1 , Figure 2 and Figure 3 , the relative dielectric constant of the dielectric layer 1 is 1.0-5.0, and the thickness of the dielectric layer 1 is 0.2-10 mm. In this embodiment, the thickness of the dielectric layer 1 is 6 mm, the relative dielectric constant is 3.5, and the loss tangent is 0.0031. In this way, the parameter design of the dielectric layer 1 can make the entire absorbing structure have better absorbing, reflecting or transmitting performance in a specific frequency band, and achieve high-performance electromagnetic absorption.

[0048] In some embodiments of the present invention, reference Figure 1 , Figure 2 and Figure 3 The second resistor layer 4 is formed by filling the mounting hole 111 with conductive paste by mechanical injection. The conductive paste can be quickly and evenly filled into the mounting hole 111 by mechanical injection, thereby improving production efficiency, ensuring that the conductive paste is well filled in the mounting hole 111, and avoiding the generation of defects such as voids and bubbles, thereby improving the conductive performance and stability of the resistor layer.

[0049] The first resistor layer 2 is formed by printing the conductive paste on the lower surface of the dielectric layer 1 or the upper surface of the substrate layer 3 by screen printing. In this embodiment, the first resistor layer 2 is formed by printing the conductive paste on the lower surface of the dielectric layer 1 by screen printing. Of course, in other embodiments, the first resistor layer 2 can also be formed by printing the conductive paste on the upper surface of the substrate layer 3 by screen printing. In this way, the conductive paste has good fluidity and plasticity, and can print various complex patterns and shapes. The conductive paste is tightly attached to the dielectric layer 1 or the substrate layer 3 by screen printing, forming a solid and reliable resistor layer, ensuring the stability and durability of the resistor layer during long-term use, thereby improving the overall reliability of the absorbing structure.

[0050] In some embodiments of the present invention, reference Figure 1 , Figure 2 and Figure 3 , the second sub-dielectric layer 1201, the first resistor layer 2 and the substrate layer 3 have the same projection shape on the horizontal plane, and are all squares with a side length of 5-15 mm. In this embodiment, the projection shapes of the second sub-dielectric layer 1201, the first resistor layer 2 and the substrate layer 3 on the horizontal plane are all squares with a side length of 10 mm. The second sub-dielectric layer 1201, the first resistor layer 2 and the substrate layer 3 are set to the same projection shape and size, so that the three layers can be more easily aligned and assembled during the design and manufacturing process, simplifying the production process, reducing the manufacturing difficulty, and improving the production efficiency. The same shape and size help to ensure the close fit and uniform distribution between the layers, and enhance the overall stability and reliability of the absorbing structure.

[0051] In some embodiments of the present invention, reference Figure 1 , Figure 2 and Figure 3The material of the dielectric layer 1 includes one or more of quartz fiber, basalt fiber, glass fiber, high boron fiber, cyanate resin, epoxy resin, polyimide, and polymethyl methacrylate; the material of the first resistor layer 2 includes one or more of carbon nanotubes, graphene, carbon nanoparticles, carbon fibers, silver nanowires, zinc oxide, zinc tin oxide, and indium tin oxide; the material of the second resistor layer 4 includes one or more of carbon nanotubes, graphene, carbon nanoparticles, carbon fibers, silver nanowires, zinc oxide, zinc tin oxide, and indium tin oxide. It is understandable that the materials of the first resistor layer 2 and the second resistor layer 4 can be the same or different. Carbon-based materials such as carbon nanotubes, graphene, and carbon fibers, as well as metal materials such as silver nanowires, have high conductivity and can effectively convert electromagnetic wave energy into heat or other forms of energy, thereby improving the wave absorbing performance and reducing the overall weight of the wave absorbing structure. The dielectric layer 1 is made of quartz fiber, glass fiber and other materials. These materials also have good electromagnetic wave transmission performance and can be used as wave-transmitting materials, which helps to optimize the electromagnetic wave absorption performance of the absorbing structure. By selecting different dielectric layer 1 materials, the electromagnetic parameters such as the dielectric constant and magnetic permeability of the absorbing structure can be adjusted to optimize its absorbing performance.

[0052] In some embodiments of the present invention, reference Figure 4 The substrate layer 3 includes a plurality of first lining units 310 and second lining units 320 alternately stacked in sequence; the first lining unit 310 and the second lining unit 320 are both carbon fiber fabric composite materials, and the first lining unit 310 and the second lining unit 320 are prepared by a hot press molding process to form the substrate layer 3. The substrate layer 3 is made of carbon fiber composite materials, which have extremely high tensile strength and modulus, so that the substrate layer 3 can withstand a large mechanical load while maintaining good shape stability. Compared with traditional metal materials, carbon fiber composite materials have a lower density, so the prepared substrate layer 3 is lighter in weight, which helps to achieve a lightweight design of the absorbing structure.

[0053] In some embodiments of the present invention, reference Figure 4 The first lining unit 310 includes a first carbon fiber reinforcement 311 and a first resin matrix 312, and the first carbon fiber reinforcement 311 is inserted into the first resin matrix 312; the second lining unit 320 includes a second carbon fiber reinforcement 321 and a second resin matrix 322, and the second carbon fiber reinforcement 321 is inserted into the second resin matrix 322; the angle between the first carbon fiber reinforcement 311 in the adjacent first lining unit 310 and the second carbon fiber reinforcement 321 in the adjacent second lining unit 320 in the ply direction is 45°. Figure 4A plurality of first carbon fiber reinforcements 311 are woven into a grid shape and then inserted into a first resin matrix 312. A plurality of second carbon fiber reinforcements 321 are woven into a grid shape and then inserted into a second resin matrix 322. The angle between the weaving direction of the first carbon fiber reinforcement 311 and the weaving direction of the second carbon fiber reinforcement 321 is 45°. The 45° ply can effectively improve the shear resistance of the composite material, thereby increasing the overall stability of the substrate layer 3. When subjected to stress, the 45° ply crossing angle can make the stress more evenly distributed, reduce the possibility of stress concentration, and thereby avoid material damage due to excessive local stress.

[0054] The second aspect of the present invention also provides an absorbing material, referring to Figure 5 , the absorbing material includes M×N absorbing structures as described in any of the above embodiments, wherein the absorbing structures are arranged in an M×N rectangular periodic dense arrangement in a two-dimensional plane, wherein M>10, N>10. Exemplarily, the absorbing material includes 15*15 absorbing structures, wherein each absorbing structure is arranged in a 15*15 rectangular periodic dense arrangement in a two-dimensional plane. Through the periodic dense arrangement, the absorbing material can form a continuous absorbing layer over a larger area, thereby more effectively absorbing and dissipating electromagnetic waves, ensuring that the electromagnetic waves are reflected and absorbed multiple times during propagation, and improving the overall absorbing performance of the absorbing material. The periodically arranged absorbing structures can form specific electromagnetic resonance modes, which help to absorb electromagnetic waves in a wider frequency band. In addition, the periodically densely arranged absorbing structures are easier to achieve standardization and large-scale production during the manufacturing process, thereby ensuring that the performance of each absorbing structure is consistent, which helps to improve the overall stability and reliability of the absorbing material.

[0055] In this embodiment, a commercial electromagnetic simulation software is used to conduct a simulation test on a wave absorbing material provided by the present invention. Figure 6 When the electromagnetic wave is incident vertically, the reflectivity of the absorbing material of this embodiment is lower than -10dB in the frequency band of 19.9GHz to 24.7GHz, and lower than -10dB in the frequency band of 20.6GHz to 21.4GHz, and the lowest reflectivity of -34.8dB is achieved at a frequency of 20.9GHz.

[0056] Reference Figure 7, when the electromagnetic wave is incident vertically, the absorbing material of this embodiment can achieve an absorption effect of more than 90% in the frequency band range of 19.9GHz to 24.7GHz, and can achieve an absorption effect of more than 99% in the frequency band range of 20.6GHz to 21.4GHz. When the incident angle of the electromagnetic wave is 30°, the absorbing material of this embodiment can achieve an absorption effect of more than 90% in the frequency band range of 20.2GHz to 25.2GHz, and can achieve an absorption effect of more than 99% in the frequency band range of 23.3GHz to 24.0GHz. With the increase of the incident angle of the electromagnetic wave, the absorption peak gradually shifts to high frequency, and the high-frequency absorption effect of the absorbing material when the electromagnetic wave is obliquely incident is better than when it is vertically incident, and when the incident angle of the electromagnetic wave is 45°, the absorbing material of this embodiment can still achieve an absorption effect of more than 90% in the frequency band range of 21.6GHz to 26.2GHz.

[0057] The above simulation results show that the absorbing material can achieve a reflectivity lower than -10dB at 19.9GHz~24.7GHz, and has a significant absorption effect. At the same time, it can still maintain more than 90% absorption in a wider frequency band when the electromagnetic wave is obliquely incident, and has good absorption stability.

[0058] The contents described above may be implemented individually or in combination in various ways, and these variations are all within the protection scope of the present invention.

[0059] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device comprising the elements.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wave absorbing structure, characterized in that: It includes a dielectric layer, a first resistance layer and a substrate layer which are stacked in sequence from top to bottom; The dielectric layer comprises a first sub-dielectric layer and a second sub-dielectric layer stacked from top to bottom, a mounting hole is provided on the first sub-dielectric layer, a second resistance layer is arranged in the mounting hole, and an upper surface of the second resistance layer is an incident surface of electromagnetic waves.

2. The wave absorbing structure according to claim 1, characterized in that: The surface resistance of the first resistance layer is 10-100Ω / □, and the surface resistance of the second resistance layer is 50-250Ω / □.

3. The wave absorbing structure according to claim 1, characterized in that: The inner diameter of the first sub-dielectric layer is smaller than the inner diameter of the second sub-dielectric layer, the projection of the first sub-dielectric layer on the horizontal plane is a square with a side length of 0.1-10 mm, and the cross-section of the second sub-dielectric layer is a square with a side length of 5-15 mm; The thickness of the second resistance layer, the thickness of the first sub-dielectric layer and the depth of the mounting hole are the same, both of which are 0.1-1.5 mm; The thickness of the first resistance layer is 0.1-0.5 mm.

4. The wave absorbing structure according to claim 1, characterized in that: The relative dielectric constant of the dielectric layer is 1.0-5.0, and the thickness of the dielectric layer is 0.2-10 mm.

5. The wave absorbing structure according to claim 1, characterized in that: The second resistance layer is formed by filling the mounting hole with conductive paste by mechanical perfusion; The first resistance layer is formed by printing the conductive paste on the lower surface of the dielectric layer or the upper surface of the substrate layer by screen printing.

6. The wave absorbing structure according to claim 1, characterized in that: The projection shapes of the second sub-dielectric layer, the first resistance layer and the substrate layer on the horizontal plane are the same, and are all squares with a side length of 5-15 mm.

7. The wave absorbing structure according to claim 1, characterized in that: The material of the dielectric layer includes one or more of quartz fiber, basalt fiber, glass fiber, high boron fiber, cyanate resin, epoxy resin, polyimide, and polymethyl methacrylate; The material of the first resistance layer includes one or more of carbon nanotubes, graphene, carbon nanoparticles, carbon fibers, silver nanowires, zinc oxide, zinc tin oxide, and indium tin oxide; The material of the second resistance layer includes one or more of carbon nanotubes, graphene, carbon nanoparticles, carbon fibers, silver nanowires, zinc oxide, zinc tin oxide, and indium tin oxide.

8. The wave absorbing structure according to claim 1, characterized in that: The substrate layer comprises a plurality of first lining layer units and second lining layer units which are alternately stacked in sequence; The first lining layer unit and the second lining layer unit are both made of carbon fiber fabric composite materials, and the first lining layer unit and the second lining layer unit are prepared by an autoclave molding process to form the substrate layer.

9. The wave absorbing structure according to claim 8, characterized in that: The first lining unit comprises a first carbon fiber reinforcement and a first resin matrix, wherein the first carbon fiber reinforcement is inserted into the first resin matrix; The second lining layer unit comprises a second carbon fiber reinforcement and a second resin matrix, and the second carbon fiber reinforcement is penetrated in the second resin matrix; The angle between the first carbon fiber reinforcement in the adjacent first lining layer unit and the second carbon fiber reinforcement in the second lining layer unit in the ply direction is 45°.

10. A wave absorbing material, characterized in that: The absorbing material comprises M×N absorbing structures as described in any one of claims 1 to 9, wherein each of the absorbing structures is arranged in a M×N rectangular periodic pattern in a two-dimensional plane, wherein M>10, N>10.

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