Wave absorbing structure and wave absorbing plate

Abstract

The invention discloses a wave-absorbing structure and a wave-absorbing plate, the wave-absorbing structure comprises a skin layer, an impedance layer, a dielectric layer and a substrate layer which are stacked in sequence, the upper surface of the skin layer is an incident plane of electromagnetic waves, the impedance layer comprises a first conductive layer and a plurality of second conductive layers, the first conductive layer is square, and the second conductive layer is square. The plurality of second conductive layers are arranged around the outer side of the first conductive layer, and the second conductive layers are square rings with openings. The wave absorbing plate comprises M * N wave absorbing structures. Through reasonable design of a multi-layer composite structure, after electromagnetic waves are incident from the skin layer, multiple interference occurs between the impedance layer and the dielectric layer, and through the synergistic effect of absorption and reflection of the impedance layer and the substrate layer, efficient dissipation of electromagnetic energy is achieved, and the high-performance electromagnetic absorption effect is achieved. Besides, due to the design form of the open square ring of the second conductive layer, the impedance layer has an impedance compensation effect, the wave-absorbing bandwidth is effectively expanded, and particularly, a relatively wide effective absorption frequency band can still be kept in an oblique incidence state of electromagnetic waves.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electromagnetic wave absorbing materials, and particularly relates to an absorbing structure and an absorbing panel. BACKGROUND

[0002] Nowadays, the problem of electromagnetic radiation pollution is not limited to military equipment stealth technology. Electromagnetic interference caused by electromagnetic radiation can also cause signal disconnection, weakening and other faults of industrial and civil equipment, and even cause serious damage to human bodies in long-term strong electromagnetic radiation. Therefore, the technology for weakening or even eliminating electromagnetic radiation has become a hot issue of concern in the society and scientific community.

[0003] The absorbing panel is a functional material capable of absorbing electromagnetic waves and dissipating electromagnetic energy. The electromagnetic wave energy can be converted into heat energy or other forms of energy and dissipated. However, current performance research on the absorbing panel is usually focused on low reflectivity, and it is difficult to have light weight, small thickness and wide frequency band performance, and the absorbing performance under large-angle oblique incidence of electromagnetic waves is usually not considered, which limits the application range of the absorbing panel in complex electromagnetic environments. SUMMARY

[0004] To overcome the problems in the related art, the present application provides an absorbing structure and an absorbing panel.

[0005] In a first aspect, the present application provides an absorbing structure, comprising: a skin layer, an impedance layer, a dielectric layer and a substrate layer which are sequentially stacked, and an upper surface of the skin layer is an incident surface of electromagnetic waves. The impedance layer comprises a first conductive layer and a plurality of second conductive layers, the first conductive layer is a square, and a plurality of the second conductive layers are arranged around the outside of the first conductive layer, and the second conductive layer is an open square ring.

[0006] In some embodiments, the opening of the second conductive layer is arranged at the top corner position of the square ring.

[0007] In some embodiments, the opening of the second conductive layer is arranged at the top corner of the square ring close to the first conductive layer.

[0008] In some embodiments, four square rings are arranged, the openings of the four square rings are respectively directed to the four top corners of the first conductive layer, and a gap is arranged between the top corner of the first conductive layer and the opening of the square ring.

[0009] In some embodiments, the side length of the first conductive layer is 3.0-10.0 mm, the outer side length of the second conductive layer is 8.0-15.0 mm, and the inner side length is 5.0-10.0 mm. and / or, The skin layer, the dielectric layer, and the substrate layer have the same projected shape in their stacking direction, and are all squares with a side length of 10.0-50.0 mm; And / or, The thickness of the skin layer is 1.0-5.0 mm, and / or the thickness of the impedance layer is 0.1-2.0 mm, and / or the thickness of the dielectric layer is 1.0-10.0 mm, and / or the thickness of the absorbing structure is less than or equal to 10.0 mm.

[0010] In some embodiments, the first conductive layer and the second conductive layer are both disposed on the surface of the dielectric layer by means of screen printing, mechanical filling or magnetron sputtering; And / or, The medium layer is formed by foaming.

[0011] In some embodiments, the sheet resistance of the impedance layer is 50-250 Ω / sq; And / or, The relative permittivity of the skin layer is 1.0-5.0; And / or, The relative permittivity of the dielectric layer is 1.0-3.0.

[0012] In some embodiments, the skin layer is configured to be physically mixed and molded from one or more materials selected from polyethylene terephthalate, polypropylene, polyimide, and polycarbonate. And / or, The material of the dielectric layer is one of polymethacrylamide foam, polyurethane foam, polystyrene foam, polystyrene foam, and low-density honeycomb material; And / or, The impedance layer is formed by physically mixing one or more of the following materials in particulate form: carbon nanotubes, graphene, carbon nanoparticles, carbon fibers, silver nanowires, zinc oxide, zinc tin oxide, and indium tin oxide. And / or, The substrate layer is a carbon fiber composite layer.

[0013] In some embodiments, the substrate layer includes a plurality of stacked liner units, wherein the plurality of liner units are formed by autoclaving. The liner unit includes a carbon fiber reinforcement and a resin matrix. The carbon fiber reinforcement is arranged and laid in the resin matrix. The layup direction between the carbon fiber reinforcements in adjacent liner units is 0°, 45° or 90°.

[0014] A second aspect of the present invention also provides a microwave absorbing plate comprising M×N microwave absorbing structures, wherein each of the microwave absorbing structures is arranged in an M×N array in a two-dimensional plane, and adjacent microwave absorbing structures are interconnected, wherein M>10 and N>10.

[0015] The technical solution provided by this invention may include the following beneficial effects: By rationally designing a multi-layered composite structure, electromagnetic waves, after entering through the skin layer, undergo multiple interferences between the impedance layer and the dielectric layer. The synergistic effect of absorption and reflection by the impedance layer and the substrate layer then achieves efficient dissipation of electromagnetic energy, resulting in high-performance electromagnetic absorption. Furthermore, the open square ring design of the second conductive layer provides impedance compensation, effectively broadening the absorption bandwidth, especially maintaining a wide effective absorption band even under oblique electromagnetic wave incidence.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0018] Figure 1 This is a perspective view of an absorbing structure according to an exemplary embodiment.

[0019] Figure 2 This is an exploded view of an absorbing structure according to an exemplary embodiment.

[0020] Figure 3 This is a schematic diagram of an impedance layer according to an exemplary embodiment.

[0021] Figure 4 This is a side view of an absorbing structure according to an exemplary embodiment.

[0022] Figure 5 This is a schematic diagram of a substrate layer according to an exemplary embodiment.

[0023] Figure 6 This is a schematic diagram of an absorbing plate according to an exemplary embodiment.

[0024] Figure 7 This is a graph illustrating the change in absorption performance in the TE direction with frequency, according to an exemplary embodiment.

[0025] Figure 8 This is a graph illustrating the change in absorption performance in the TM direction with frequency, according to an exemplary embodiment.

[0026] Figure label: 100. Absorbing structure; 1. Skin layer; 2. Impedance layer; 21. First conductive layer; 22. Second conductive layer; 3. Dielectric layer; 4. Substrate layer; 41. Liner unit; 411. Carbon fiber reinforcement; 412. Resin matrix. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.

[0028] A microwave absorbing plate is a functional material that can absorb electromagnetic waves and dissipate electromagnetic energy, converting electromagnetic wave energy into heat or other forms of energy for dissipation. However, current research on the performance of microwave absorbing plates usually focuses on low reflectivity, making it difficult to simultaneously achieve the three properties of light weight, small thickness, and wide bandwidth. Furthermore, it typically does not consider the absorption performance under large-angle oblique incidence of electromagnetic waves, limiting its application range in complex electromagnetic environments.

[0029] To address the technical problems existing in related technologies, this application provides an absorbing structure and an absorbing plate. The absorbing structure includes a skin layer, an impedance layer, a dielectric layer, and a substrate layer stacked sequentially. The upper surface of the skin layer serves as the incident surface for electromagnetic waves. The impedance layer includes a first conductive layer and multiple second conductive layers. The first conductive layer is square, and the multiple second conductive layers are arranged around the outside of the first conductive layer, each second conductive layer being an open square ring. The absorbing plate includes M×N absorbing structures, each arranged in an M×N array in a two-dimensional plane, with adjacent absorbing structures interconnected, where M>10 and N>10. By rationally designing the multi-layer composite structure, electromagnetic waves, after entering through the skin layer, undergo multiple interferences between the impedance layer and the dielectric layer. The synergistic effect of absorption and reflection by the impedance layer and the substrate layer then achieves efficient dissipation of electromagnetic energy, resulting in high-performance electromagnetic absorption. Furthermore, the open square ring design of the second conductive layer provides impedance compensation for the impedance layer, effectively broadening the absorption bandwidth, especially maintaining a wide effective absorption band even under oblique electromagnetic wave incidence.

[0030] See Figure 1 , Figure 2 and Figure 4An exemplary embodiment of this disclosure provides a microwave absorbing structure 100, comprising a skin layer 1, an impedance layer 2, a dielectric layer 3, and a substrate layer 4 stacked sequentially. The upper surface of the skin layer 1 serves as the incident surface for electromagnetic waves. The skin layer 1 protects the entire microwave absorbing structure 100, while the substrate layer 4 prevents electromagnetic waves from passing through. After the electromagnetic wave enters through the skin layer 1, it undergoes multiple interferences between the impedance layer 2 and the dielectric layer 3. Through the synergistic effect of absorption and reflection by the impedance layer 2 and the substrate layer 4, efficient dissipation of electromagnetic energy is achieved, resulting in high-performance electromagnetic absorption. The stacked structure of the microwave absorbing structure 100 in this invention has the advantages of good impedance matching, strong absorption performance, and wide absorption bandwidth, making it an important means of achieving high-intensity, wide-bandwidth absorption.

[0031] like Figure 3 As shown, the impedance layer 2 includes a first conductive layer 21 and multiple second conductive layers 22. The first conductive layer 21 is square, and the multiple second conductive layers 22 are arranged around the outside of the first conductive layer 21. Each second conductive layer 22 is an open square ring. The design of the open square ring makes the entire impedance layer 2 form an equivalent circuit, realizing impedance compensation for the absorbing structure 100. Even if the equivalent impedance changes dynamically due to the oblique incidence of electromagnetic waves, this design can still effectively absorb electromagnetic waves, ultimately achieving a broadening of the absorption bandwidth in oblique incidence scenarios. In addition, by utilizing the electromagnetic response of the substrate layer 4 in combination with the structural design of the impedance layer 2, magnetic field oscillation is jointly excited, generating a resonant coupling phenomenon in electromagnetic interaction, thereby enhancing electromagnetic energy absorption, broadening the absorption frequency band, and optimizing performance stability in oblique incidence scenarios.

[0032] See Figure 3 In some embodiments, the opening of the second conductive layer 22 is located at the top corner of the square ring. For example, the opening of the second conductive layer 22 is located at the top corner of the square ring near the first conductive layer 21, which facilitates processing, makes the impedance parameter control of the equivalent circuit more precise, further improves the impedance compensation accuracy, and better realizes the impedance compensation function.

[0033] See Figure 3 In some embodiments, the openings of the four square rings point to the four vertices of the first conductive layer 21, and the four open square rings are centrally symmetrically distributed to reduce electromagnetic reflection deviation during oblique incidence. Gaps are provided between the vertices of the first conductive layer 21 and the openings of the square rings, which enhances the impedance compensation effect of the equivalent circuit formed by the entire impedance layer 2. For example, the width of the gap is 0.1-10 mm, optimizing the electrical parameters and electromagnetic coupling characteristics of the equivalent circuit of the impedance layer 2, improving impedance compensation accuracy, broadening the absorption bandwidth, and enhancing oblique incidence stability.

[0034] In some embodiments, the impedance layer 2 is a frequency selective surface (FSS) impedance layer, which can adjust the impedance value according to the requirements, resulting in better broadband absorption performance. The frequency selective surface impedance layer has the advantages of being lightweight, thin, and structurally stable, which can ensure the absorption effect and structural stability of the absorbing structure 100.

[0035] See Figure 3 In some embodiments, the first conductive layer 21 has a side length of 3.0-10.0 mm, the second conductive layer 22 has an outer side length of 8.0-15.0 mm and an inner side length of 5.0-10.0 mm, and the sheet resistance of the impedance layer 2 is 50-250 Ω / sq. This allows electromagnetic waves to smoothly enter the absorbing structure 100 and dissipate their energy within the impedance layer 2, converting it into heat energy and achieving electromagnetic wave absorption. Both the first conductive layer 21 and the second conductive layer 22 are deposited on the surface of the dielectric layer 3 by screen printing, mechanical filling, or magnetron sputtering. The conductive paste has good fluidity and plasticity, enabling the printing of various complex patterns and shapes. The conductive paste adheres tightly to the dielectric layer 3 through screen printing, forming a robust and reliable resistive layer. This ensures the stability and durability of the resistive layer during long-term use, thereby improving the overall reliability of the absorbing structure 100. Mechanical filling avoids the generation of defects such as voids and bubbles, thus improving the conductivity and stability of the resistive layer. Magnetron sputtering enables the first conductive layer 21 and the second conductive layer 22 to have the advantages of high purity and high density, avoiding defects such as pores and pinholes, and ensuring uniformity of surface resistivity.

[0036] In some embodiments, see Figure 1 , Figure 2 and Figure 4 The skin layer 1, dielectric layer 3, and substrate layer 4 have identical projected shapes in their stacking direction, and are all squares with side lengths of 10.0-50.0 mm. This allows for easier alignment and assembly of these three layers during design and manufacturing, simplifying the production process, reducing manufacturing difficulty, and improving production efficiency. The identical shape and size help ensure tight bonding and uniform distribution between the layers, enhancing the overall stability and reliability of the absorbing structure 100. The overall thickness of the absorbing structure 100 is less than or equal to 10.0 mm. Specifically, the thickness of the skin layer 1 is 1.0-5.0 mm, the thickness of the impedance layer 2 is 0.1-2.0 mm, and the thickness of the dielectric layer 3 is 1.0-10.0 mm, ensuring both effective absorption and lightweight design.

[0037] In some embodiments, the relative permittivity of the skin layer 1 is 1.0-5.0 and the relative permittivity of the dielectric layer 3 is 1.0-3.0, which enables electromagnetic waves to smoothly enter the absorbing structure 100 and interfere with each other in the dielectric layer 3.

[0038] In some embodiments, the skin layer 1 is configured to be physically mixed and molded from one or more materials selected from polyethylene terephthalate, polypropylene, polyimide, and polycarbonate. Polyethylene terephthalate, polypropylene, polyimide, and polycarbonate all possess good resistance to high and low temperatures, damp heat, and ultraviolet radiation, and are not prone to aging, cracking, or deformation. They effectively block the intrusion of external moisture, dust, and chemical media, which helps prevent oxidation of the internal impedance layer 2 and failure of the dielectric layer 3, thus protecting the entire microwave absorbing structure 100. Furthermore, polyethylene terephthalate, polypropylene, polyimide, and polycarbonate all have low densities, which will not significantly increase the total weight of the microwave absorbing structure 100, contributing to its lightweight design. The dielectric layer 3 is made of one of polymethacrylamide foam, polyurethane foam, polystyrene foam, or low-density honeycomb materials, and is molded using a foaming method, offering flexible processing and low cost. The dielectric layer 3, serving as the support layer for the impedance layer 2, features low dielectric loss, low density, and high porosity. This helps ensure the structural stability of the material, provides space for multiple reflections and interferences of electromagnetic waves within the layer, extends the energy propagation path, improves absorption efficiency, and reduces the overall weight of the absorbing structure 100. The impedance layer 2 is formed by physically mixing one or more materials selected from carbon nanotubes, graphene, carbon nanoparticles, carbon fibers, silver nanowires, zinc oxide, zinc tin oxide, and indium tin oxide in particulate form. Carbon-based materials such as carbon nanotubes, graphene, and carbon fibers, as well as metallic materials such as silver nanowires, have high conductivity, effectively converting electromagnetic wave energy into heat energy or other forms of energy, thereby improving absorption performance and reducing the overall weight of the absorbing structure 100.

[0039] In some embodiments, the substrate layer 4 is a carbon fiber composite layer. Carbon fiber composite materials possess extremely high tensile strength and modulus, enabling the substrate layer 4 to withstand large mechanical loads while maintaining good shape stability. Compared to traditional metal materials, carbon fiber composite materials have lower density, resulting in a lighter substrate layer 4, which contributes to the lightweight design of the microwave absorbing structure 100. Exemplarily, the substrate layer 4 includes multiple stacked liner units 41, which are formed by autoclaving, ensuring tight fusion of the multiple liner units 41 and improving the overall structural integrity. Each liner unit 41 includes carbon fiber reinforcement 411 and a resin matrix 412. The carbon fiber reinforcement 411 is arranged and laid within the resin matrix 412, and the angle between the layup directions of the carbon fiber reinforcement 411 in adjacent liner units 41 is 0°, 45°, or 90°. See also... Figure 5In one exemplary embodiment, multiple carbon fiber reinforcements 411 are woven into a mesh and then laid within the resin matrix 412, with the included angle between the weaving directions of each carbon fiber reinforcement 411 being 45°. 0°, 45°, or 90° layups can effectively improve the shear resistance of the composite material, thereby increasing the overall stability of the substrate layer 4. Under stress, the intersection angles of 0°, 45°, or 90° layups can make the stress distribution more uniform, reducing the possibility of stress concentration and thus preventing material failure due to excessive local stress.

[0040] A microwave absorbing panel includes M×N microwave absorbing structures 100, wherein each microwave absorbing structure 100 is arranged in an M×N array in a two-dimensional plane, and adjacent microwave absorbing structures 100 are interconnected, wherein M>10 and N>10. (See reference...) Figure 6 In one exemplary embodiment, the absorbing panel includes 15×15 absorbing structures 100, wherein each absorbing structure 100 is arranged in a 15×15 array in a two-dimensional plane, and adjacent absorbing structures 100 are interconnected. Through this array arrangement, the absorbing panel can form a continuous absorbing layer over a larger area, thereby more effectively absorbing and dissipating electromagnetic waves, ensuring that electromagnetic waves are reflected and absorbed multiple times during propagation, improving the overall absorption performance of the absorbing panel. The arrayed absorbing structures 100 can form specific electromagnetic resonance modes, which helps to absorb electromagnetic waves over a wider frequency band. Furthermore, the arrayed absorbing structures 100 are easier to standardize and mass-produce during manufacturing, ensuring consistent performance of each absorbing structure 100, and contributing to improved overall stability and reliability of the absorbing panel.

[0041] To facilitate the explanation of the technical solution of this disclosure, in an exemplary embodiment, the wave absorbing structure 100 includes a skin layer 1, an impedance layer 2, a dielectric layer 3 and a substrate layer 4 stacked sequentially, and the surface of the skin layer 1 facing away from the impedance layer 2 is the incident surface of the electromagnetic wave.

[0042] In this embodiment, refer to Figures 3-4 The skin layer 1 is made of polytetrafluoroethylene plastic with a relative permittivity of 2.1, a loss tangent of 0.003, and a thickness h1 of 2.0 mm. The outer side length a1 of the square ring of the impedance layer 2 is 12.0 mm, the inner side length a2 is 8.0 mm, the inner side length b of the open ring is 7.0 mm, the side length c of the solid square ring is 6.0 mm, the spacing g between two adjacent square rings is 2.0 mm, the thickness h2 of the impedance layer 2 is 0.2 mm, and the resistance is 150 Ω / sq. The dielectric layer 3 is made of highly foamed polyurethane foam with a relative permittivity of 1.05, a loss tangent of 0.02, and a thickness h3 of 5.0 mm. The substrate layer 44 is made of T800 carbon fiber epoxy resin-based composite material with a thickness h4 of 0.5 mm. The side length D of the absorbing structure 100 is 28.0 mm.

[0043] like Figure 7 As shown, the TE (Transverse Electric) direction is the transverse electric wave direction, specifically the direction of electric field vibration perpendicular to the normal of the absorbing structure (the direction of electromagnetic wave propagation), and vibrating only along the polarization direction of the electromagnetic wave incident surface of the absorbing structure. When the electromagnetic wave is incident perpendicularly, in the TE direction, the absorbing structure 100 of this embodiment can achieve an absorption effect of over 99% in the 7.3GHz~15.7GHz frequency band and over 90% in the 5.0GHz~18.9GHz frequency band. When the electromagnetic wave incident angle is 30°, the absorbing structure 100 of this embodiment can achieve an absorption effect of over 99% in the 8.2GHz~16.4GHz frequency band and over 90% in the 5.3GHz~18.5GHz frequency band. As the electromagnetic wave incident angle increases, the absorbing structure 100 of this embodiment can achieve an absorption effect of over 90% in the 5.5GHz~18.0GHz frequency band, exhibiting good absorption stability.

[0044] like Figure 8 As shown, the TM (Transverse Magnetic) direction is the transverse magnetic wave direction, specifically the direction of magnetic field vibration perpendicular to the normal of the absorbing structure (the direction of electromagnetic wave propagation), and vibrating only along the polarization direction of the electromagnetic wave incident surface of the absorbing structure. When the electromagnetic wave is incident perpendicularly, in the TM direction, the absorbing structure 100 of this embodiment can achieve an absorption effect of over 99% in the 7.3GHz~15.7GHz frequency band and over 90% in the 5.0GHz~18.9GHz frequency band. When the electromagnetic wave incident angle is 30°, the absorbing structure 100 of this embodiment can achieve an absorption effect of over 99% in the 10.0GHz~14.6GHz frequency band and over 90% in the 5.9GHz~21.6GHz frequency band. As the electromagnetic wave incident angle increases, the absorbing structure 100 of this embodiment has a better absorption effect in the TM direction than in the TE direction, and also has good absorption stability.

[0045] The above embodiments illustrate that, regardless of whether the electromagnetic wave is incident perpendicularly or obliquely into the absorbing structure 100 in the TE or TM direction, absorption of more than 90% can be achieved in the range of 6.0 GHz to 18.0 GHz, and absorption of more than 99% can be achieved in the range of 10.0 GHz to 14.6 GHz. This demonstrates that the absorbing structure 100 of this embodiment has a significant absorption effect, and at the same time, it can still maintain good absorption stability over a wide frequency band when the electromagnetic wave is incident obliquely.

[0046] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0047] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A wave-absorbing structure, characterized in that, It includes a skin layer, an impedance layer, a dielectric layer and a substrate layer stacked in sequence, wherein the upper surface of the skin layer is the incident surface of the electromagnetic wave; The impedance layer includes a first conductive layer and a plurality of second conductive layers. The first conductive layer is square, and the plurality of second conductive layers are disposed around the outside of the first conductive layer. The second conductive layers are open square rings.

2. The absorbing structure according to claim 1, characterized in that, The opening of the second conductive layer is located at the top corner of the square ring.

3. The absorbing structure according to claim 2, characterized in that, The opening of the second conductive layer is located at the top corner of the square ring near the first conductive layer.

4. The absorbing structure according to claim 3, characterized in that, The square rings are provided in four parts, and the openings of the four square rings point to the four vertices of the first conductive layer, and a gap is provided between the vertices of the first conductive layer and the openings of the square rings.

5. The absorbing structure according to claim 1, characterized in that, The first conductive layer has a side length of 3.0-10.0 mm, and the second conductive layer has an outer side length of 8.0-15.0 mm and an inner side length of 5.0-10.0 mm. And / or, The skin layer, the dielectric layer, and the substrate layer have the same projected shape in their stacking direction, and are all squares with a side length of 10.0-50.0 mm; And / or, The thickness of the skin layer is 1.0-5.0 mm, and / or the thickness of the impedance layer is 0.1-2.0 mm, and / or the thickness of the dielectric layer is 1.0-10.0 mm, and / or the thickness of the absorbing structure is less than or equal to 10.0 mm.

6. The microwave absorbing structure according to claim 1, characterized in that, Both the first conductive layer and the second conductive layer are deposited on the surface of the dielectric layer by means of screen printing, mechanical filling or magnetron sputtering; And / or, The medium layer is formed by foaming.

7. The absorbing structure according to claim 1, characterized in that, The sheet resistance of the impedance layer is 50-250Ω / sq; And / or, The relative permittivity of the skin layer is 1.0-5.0; And / or, The relative permittivity of the dielectric layer is 1.0-3.

0.

8. The absorbing structure according to claim 1, characterized in that, The skin layer is configured to be physically mixed and molded from one or more of the following materials: polyethylene terephthalate, polypropylene, polyimide, and polycarbonate. And / or, The material of the dielectric layer is one of polymethacrylamide foam, polyurethane foam, polystyrene foam, polystyrene foam, and low-density honeycomb material; And / or, The impedance layer is formed by physically mixing one or more of the following materials in particulate form: carbon nanotubes, graphene, carbon nanoparticles, carbon fibers, silver nanowires, zinc oxide, zinc tin oxide, and indium tin oxide. And / or, The substrate layer is a carbon fiber composite layer.

9. The absorbing structure according to claim 8, characterized in that, The substrate layer includes a plurality of stacked liner units, and the plurality of liner units are formed by autoclaving. The liner unit includes a carbon fiber reinforcement and a resin matrix. The carbon fiber reinforcement is arranged and laid in the resin matrix. The layup direction between the carbon fiber reinforcements in adjacent liner units is 0°, 45° or 90°.

10. A wave-absorbing plate, characterized in that, Including M×N as described in claim 1 above. The absorbing structure according to any one of the following 9, wherein each of the absorbing structures is arranged in an M×N array in a two-dimensional plane, and adjacent absorbing structures are interconnected, wherein M>10 and N>10.

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