Ultra-wideband high-performance wave-absorbing structure based on double-layer metasurface

Abstract

The invention relates to an ultra-wideband high-performance wave-absorbing structure based on a double-layer metasurface. The ultra-wideband high-performance wave-absorbing structure based on the double-layer metasurface sequentially comprises a metal layer, an adhesive film layer, a first dielectric layer, an adhesive film layer, a lower metasurface layer, an adhesive film layer, a second dielectric layer, an adhesive film layer and an upper metasurface layer from bottom to top. The lower metasurface layer comprises a plurality of lower metasurface basic units which are periodically arranged, the lower metasurface basic units are annular regular octagons, the upper metasurface layer comprises a plurality of upper metasurface basic units which are periodically arranged, and each upper metasurface basic unit is composed of an inner annular regular octagon and an outer annular regular octagon which are different in size. Compared with the same wave-absorbing structure with only two layers of metasurfaces, the wave-absorbing structure designed by the invention shows more excellent wave-absorbing performance and larger wave-absorbing bandwidth, and the wave-absorbing structure in the invention has the characteristics of few product layers, easier processing and forming, obviously simplified product assembly, high product stability and yield and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of wave absorbing structures, and in particular relates to an ultra-wideband high-performance wave absorbing structure based on a double-layer metasurface. Background Art

[0002] High-performance absorbing structures are widely used in two major fields, including anti-electromagnetic interference and electromagnetic shielding. With the increasing miniaturization, high frequency and high-density integration of electronic equipment, problems such as conducted interference and electromagnetic radiation interference within the equipment have become particularly prominent. In order to resist and weaken the interference of electromagnetic waves and improve the performance of radar or communication equipment, it is necessary to develop and apply new absorbing structures, which is one of the important means to resist electromagnetic interference.

[0003] With the improvement of the performance of electronic equipment, the performance requirements for absorbing structures are getting higher and higher. The absorbing structures are required to have the characteristics of large bandwidth, few layers, lightness, good absorption performance, simple molding, simple product assembly, good product stability, and high product yield (qualified rate). The existing conventional absorbing structures either usually have excellent absorbing performance within a large bandwidth, but the product structure is generally thick, the number of layers is large, and the product assembly process is complex, which easily leads to a decrease in product yield; or the absorbing structure is light and thin, but the absorbing bandwidth is narrow, which cannot meet the development needs of lightweight absorbing materials, large bandwidth, and high absorbing performance.

[0004] Therefore, in view of the shortcomings of current conventional absorbing structures and the future development needs of absorbing structures, it is very necessary to propose an absorbing structure with ultra-wideband and high absorbing performance in a light and thin structure. Summary of the invention

[0005] In order to solve one or more technical problems existing in the prior art, the present invention provides an ultra-wideband high-performance absorbing structure based on a double-layer metasurface.

[0006] In a first aspect, the present invention provides an ultra-wideband high-performance absorbing structure based on a double-layer supersurface, wherein the ultra-wideband high-performance absorbing structure based on the double-layer supersurface comprises, from bottom to top, a metal layer, a film layer, a first dielectric layer, a film layer, a lower supersurface layer, a film layer, a second dielectric layer, a film layer and an upper supersurface layer; the lower supersurface layer comprises a plurality of periodically arranged lower supersurface basic units, wherein the lower supersurface basic unit is an annular regular octagon, and the upper supersurface layer comprises a plurality of periodically arranged upper supersurface basic units, wherein the upper supersurface basic unit is composed of two inner and outer annular regular octagons of different sizes.

[0007] Preferably, the longest diagonal line l1 of the lower super surface basic unit is 8.5-9.5 mm, and the width W1 is 2.0-2.5 mm.

[0008] Preferably, the upper super surface basic unit is composed of an outer annular regular octagon and an inner annular regular octagon, and the outer annular regular octagon and the inner annular regular octagon are concentrically arranged; the longest diagonal l2 of the outer annular regular octagon is 6.5-7.3 mm, and the width W2 is 0.8-1.3 mm; the longest diagonal l3 of the inner annular regular octagon is 3.5-4.5 mm, and the width W3 is 0.2-0.6 mm.

[0009] Preferably, the lower super surface layer is composed of a substrate and a carbon black film arranged on the substrate, and the lower super surface basic units are etched in the carbon black film; the upper super surface layer is composed of a substrate and a carbon black film arranged on the substrate, and the upper super surface basic units are etched in the carbon black film; the lower super surface basic units and the upper super surface basic units are arranged with the same arrangement period in the x direction and the y direction, and the arrangement period is 9 mm.

[0010] Preferably, the carbon black film surface in the lower super surface layer is arranged toward the first medium layer; and the carbon black film surface in the upper super surface layer is arranged toward the second medium layer.

[0011] Preferably, the square resistance of the carbon black film in the lower super surface layer is 40 to 70 Ω / sq; and / or the square resistance of the carbon black film in the upper super surface layer is 70 to 120 Ω / sq, preferably 70 to 100 Ω / sq.

[0012] Preferably, the thickness of the lower super surface layer and / or the upper super surface layer is 50-80 μm; and / or the substrate is made of polyimide material.

[0013] Preferably, the thickness t0 of the first dielectric layer is 1.3-1.7 mm; the thickness t1 of the second dielectric layer is 1.8-2.2 mm; and / or the thickness of the adhesive film layer t2 is 0.08-0.15 mm.

[0014] Preferably, the metal layer is made of a metal plate; and / or the first dielectric layer and / or the second dielectric layer is made of PP foam or PMI foam.

[0015] Preferably, the total thickness of the ultra-wideband high-performance absorbing structure is less than or equal to 4.3 mm.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects:

[0017] (1) The ultra-wideband high-performance absorbing structure based on a double-layer metasurface proposed in the present invention solves one or more technical problems of the previous absorbing structures, such as being thick, having poor absorbing performance, having a narrow bandwidth, and having a complex structure. The absorbing structure designed in the present invention has a smaller thickness (fewer layers, only two layers of metasurface) than the absorbing structure with only two layers of metasurface, and exhibits better absorbing performance and a larger absorbing bandwidth. Although CN115832720A or CN117335167A both disclose a broadband absorbing structure having excellent absorbing performance within an ultra-large bandwidth of 30 GHz, the absorbing structures in these patent applications have many layers and need to involve a three-layer metasurface structure. The broadband absorbing structures based on three or more layers of metasurfaces often have complex product assembly and require more connection and docking steps during assembly, which can easily lead to large assembly errors of the product, affecting the stability of the product and the problem of low product yield. The ultra-wideband high-performance absorbing structure based on a double-layer metasurface of the present invention has Compared with the absorbing structure based on three-layer metasurface, since it is composed of only two layers of metasurface, the two layers of metasurface are easier to align units from top to bottom, which simplifies the molding of the product and further avoids the influence of structural molding on performance. The product assembly and molding process are significantly simplified, making the production process more efficient and low-cost, while improving the consistency and yield of the product, thereby helping to improve the overall competitiveness of the product. Specifically, the double-layer metasurface structure reduces the total number of layers, reduces the complexity of assembly, and reduces the connection and docking steps required during assembly, thereby improving production efficiency. The double-layer metasurface structure simplifies the process steps and reduces the risk of product assembly defects, especially in automated production lines. This is very beneficial for improving production efficiency and reducing costs. In addition, since the number of layers of the absorbing structure in the present invention is reduced, the problem of poor contact between layers is reduced during the molding process, which is also beneficial to improving the stability of the final product, thereby also improving the consistency and yield (qualified rate) of the product.

[0018] (2) The ultra-wideband high-performance absorbing structure based on the double-layer metasurface in the present invention includes, from bottom to top, a metal layer, a film layer, a first dielectric layer, a film layer, a lower metasurface layer, a film layer, a second dielectric layer, a film layer and an upper metasurface layer, wherein the lower metasurface layer includes a plurality of periodically arranged lower metasurface basic units, each of which is a ring-shaped regular octagon, and the upper metasurface layer includes a plurality of periodically arranged upper metasurface basic units, each of which is composed of two inner and outer ring-shaped regular octagons of different sizes. The present invention finds that by designing the metasurface basic units in the upper metasurface layer as two ring-shaped regular octagons of different sizes, multiple resonant frequencies can be introduced, and each ring-shaped structure (inner and outer rings) has a plurality of periodically arranged upper metasurface basic units, each of which ... ) can produce resonance effects in different frequency ranges respectively, which can achieve wider frequency band coverage and effectively expand the absorbing frequency band. Compared with designing the upper metasurface basic unit as a single annular regular octagonal structure, the two annular structures of different sizes can work simultaneously in a wider frequency range to achieve more uniform absorbing characteristics, which helps to improve the broadband absorption capacity of the entire absorbing structure. The combination of the inner and outer annular regular octagons can optimize the coupling efficiency of the electromagnetic wave and the metasurface structure, so that when the electromagnetic wave passes through the two structures of different scales, it will resonate with the electromagnetic wave at multiple different frequency points. The overlap of the resonant responses excited at multiple frequency points improves the absorption bandwidth of the absorbing structure.

[0019] (3) The present invention conducts electromagnetic performance tests on a flat plate sample with a structural size of 180mm×180mm. The actual test results show that the reflection coefficient of the structure is ≤-10dB within an ultra-large bandwidth of 30GHz, and the structure is composed of only two layers of metasurfaces with a thickness of ≤4.3mm. It is easier to process and shape, and the product assembly is significantly simplified. The product stability and yield (qualified rate) are high. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 The structure diagram of the ultra-wideband high-performance absorbing structure based on the double-layer super surface of the present invention is shown in the figure. In the figure, 1: metal layer; 2: adhesive film layer; 3: dielectric layer; 4: lower super surface layer; 5: upper super surface layer;

[0022] Figure 2It is a schematic diagram of the array structure of the lower super surface basic unit and the upper super surface basic unit of the present invention; in the figure, 41: lower super surface basic unit; 51: upper super surface basic unit; 42: lower super surface basic unit array; 52: upper super surface basic unit array;

[0023] Figure 3 It is a structural schematic diagram of the lower super surface basic unit of the present invention;

[0024] Figure 4 It is a structural schematic diagram of the upper super surface basic unit of the present invention;

[0025] Figure 5 is a reflection coefficient test curve of the ultra-wideband high-performance absorbing structure based on a double-layer metasurface under horizontal polarization in Example 1 of the present invention;

[0026] Figure 6 This is a reflection coefficient test curve of the ultra-wideband high-performance absorbing structure based on the double-layer metasurface in Example 1 of the present invention under vertical polarization. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] In a first aspect, the present invention provides an ultra-wideband high-performance absorbing structure based on a double-layer metasurface, wherein the ultra-wideband high-performance absorbing structure based on the double-layer metasurface comprises, from bottom to top, a metal layer, a film layer, a first dielectric layer, a film layer, a lower metasurface layer, a film layer, a second dielectric layer, a film layer and an upper metasurface layer, for example, Figure 1 As shown; in the present invention, the first dielectric layer and the second dielectric layer can be collectively referred to as dielectric layers; in the present invention, a metal base layer, two dielectric layers and two super surface layers are bonded by four layers of adhesive film layers to form a typical "sandwich" structure of the absorbing material; the lower super surface layer includes a plurality of periodically arranged lower super surface basic units, for example, Figure 2 As shown, the lower super surface basic unit is a ring-shaped regular octagon, for example, Figure 3 As shown; the upper super surface layer includes a plurality of periodically arranged upper super surface basic units, for example, Figure 2 As shown, the upper supersurface basic unit is composed of two inner and outer annular regular octagons of different sizes, for example, Figure 4As shown; in the present invention, the lower super surface basic units and the upper super surface basic units are cross-periodically and repeatedly arranged in a two-dimensional plane to form a periodic array.

[0029] The ultra-wideband high-performance absorbing structure based on a double-layer metasurface proposed in the present invention solves one or more technical problems of the previous absorbing structures such as thickness, poor absorbing performance, narrow bandwidth, and complex structure. The absorbing structure designed by the present invention has a smaller thickness (few layers, only two layers of metasurface), and shows better absorbing performance and larger absorbing bandwidth than the absorbing structure with only two layers of metasurface. Although CN115832720A or CN117335167A both disclose a broadband absorbing structure with excellent absorbing performance within an ultra-large bandwidth of 30 GHz, the absorbing structures in these patent applications have many layers and need to involve a three-layer metasurface structure. The broadband absorbing structures based on three or more layers of metasurfaces often have complex product assembly and many connection and docking steps required during assembly, which can easily lead to large assembly errors of the products, affecting the stability of the products and the low product yield. The ultra-wideband high-performance absorbing structure based on a double-layer metasurface of the present invention Compared with the absorbing structure based on three-layer metasurface, since it is composed of only two layers of metasurface, the two layers of metasurface are easier to align units from top to bottom, which simplifies the molding of the product and further avoids the influence of structural molding on the performance. The product assembly and molding process are significantly simplified, making the production process more efficient and low-cost, while improving the consistency and yield of the product, which helps to improve the overall competitiveness of the product. Specifically, the double-layer metasurface structure reduces the total number of layers, reduces the complexity of assembly, and reduces the connection and docking steps required during assembly, thereby improving production efficiency. The double-layer metasurface structure simplifies the process steps and reduces the risk of product assembly defects, especially in automated production lines. This is very beneficial for improving production efficiency and reducing costs. In addition, since the number of layers of the absorbing structure in the present invention is reduced, the problem of poor contact between layers is reduced during the molding process, which is also beneficial to improving the stability of the final product, thereby improving the consistency and yield of the product.The ultra-wideband high-performance absorbing structure based on a double-layer super surface in the present invention includes a metal layer, a film layer, a first dielectric layer, a film layer, a lower super surface layer, a film layer, a second dielectric layer, a film layer and an upper super surface layer from bottom to top, wherein the lower super surface layer includes a plurality of periodically arranged lower super surface basic units, and the super surface basic unit is an annular regular octagon, and the upper super surface layer includes a plurality of periodically arranged upper super surface basic units, and the super surface basic unit is composed of two inner and outer annular regular octagons of different sizes. The present invention finds that by designing the super surface basic unit in the upper super surface layer as two annular regular octagon structures of different sizes, multiple resonant frequencies can be introduced, and each annular structure (inner and outer rings) can produce resonance effects in different frequency ranges, respectively, so as to achieve wider frequency band coverage and effectively expand the absorbing frequency band. Compared with the structure in which the upper super surface basic unit is designed as a single annular regular octagon, the two annular structures of different sizes can play a role simultaneously in a wider frequency range to achieve more uniform absorbing characteristics, which helps to improve the broadband of the entire absorbing structure. The invention discloses a method for realizing a wave absorbing structure having a plurality of surfaces and a plurality of structures, wherein the surface of the wave absorbing structure has a plurality of surfaces and a plurality of structures, and ...

[0030] In the present invention, the lower super surface basic units and the upper super surface basic units are arranged in a vertical direction (y direction) with a period of P and in a horizontal direction (x direction) with a period of P to form a unit array (periodic array). In the present invention, for example, 20 to 30 upper super surface basic units are arranged in the horizontal and vertical directions of the upper super surface layer, and 20 to 30 lower super surface basic units are arranged in the horizontal and vertical directions of the lower super surface layer. Finally, the absorbing structure is processed as a whole into a flat sample with a size, and the electromagnetic performance of the sample is tested. It can be seen from the measured test results that the ultra-wideband high-performance absorbing structure of the basic double-layer super surface proposed in the present invention realizes ultra-wideband high-performance absorption, and the structure is thinner and lighter. In some specific embodiments, the present invention performs electromagnetic performance tests on flat sample with a structural size of 180mm×180mm. The measured test results show that the reflection coefficient of the structure is ≤-10dB within an ultra-large bandwidth of 30GHz, and the structure is composed of only two layers of super surfaces with a thickness of ≤4.3mm, which is easier to process and form, and the product assembly is significantly simplified, and the product stability and yield are high.

[0031] According to some preferred embodiments, the longest diagonal line l1 (ie, the length of the longest diagonal line l1) of the lower super surface basic unit is 8.5-9.5 mm, preferably 9 mm, and the width W1 is 2.0-2.5 mm.

[0032] According to some preferred embodiments, the upper super surface basic unit is composed of an outer annular regular octagon and an inner annular regular octagon, and the outer annular regular octagon and the inner annular regular octagon are concentrically arranged; the longest diagonal l2 of the outer annular regular octagon (i.e., the length of the longest diagonal l2) is 6.5-7.3 mm, and the width W2 is 0.8-1.3 mm; the longest diagonal l3 of the inner annular regular octagon (i.e., the length of the longest diagonal l3) is 3.5-4.5 mm, and the width W3 is 0.2-0.6 mm.

[0033] The present invention can effectively improve the broadband absorbing performance of the ultra-wideband high-performance absorbing structure by reasonably designing the structural parameters of the lower supersurface basic unit and the upper supersurface basic unit. The present invention can effectively reduce reflection and enhance absorption through the size coordination design of the lower supersurface basic unit and the upper supersurface basic unit, which is helpful to improve the absorbing performance in the low-frequency and high-frequency ranges, and can enhance the ultra-wideband absorbing performance through synergistic effect to meet the needs of multi-band applications. If the size design of the lower supersurface basic unit and the upper supersurface basic unit is inappropriate, it will affect the overall multi-resonance effect of the absorbing structure, thereby affecting the broadband absorbing performance.

[0034] According to some preferred embodiments, the lower super surface layer is composed of a substrate and a carbon black film arranged on the substrate, and the lower super surface basic unit is etched in the carbon black film; the upper super surface layer is composed of a substrate and a carbon black film arranged on the substrate, and the upper super surface basic unit is etched in the carbon black film; in the lower super surface layer and the upper super surface layer in the present invention, the carbon black film is, for example, scraped on the substrate; in the present invention, the etching is, for example, laser etching; the lower super surface basic unit and the upper super surface basic unit are arranged with the same arrangement period P in the x direction and the y direction, and the arrangement period is 9 mm; in the present invention, in the lower super surface layer, the arrangement period also refers to the distance between the center points of two adjacent lower super surface basic units, and in the upper super surface layer, the arrangement period also refers to the distance between the center points of two adjacent upper super surface basic units.

[0035] According to some preferred embodiments, the carbon black film surface in the lower super surface layer is arranged toward the first medium layer; and the carbon black film surface in the upper super surface layer is arranged toward the second medium layer.

[0036] According to some preferred embodiments, the square resistance of the carbon black film in the lower super surface layer is 40 to 70 Ω / sq (for example, 40, 50, 60 or 70 Ω / sq); and / or the square resistance of the carbon black film in the upper super surface layer is 70 to 120 Ω / sq (for example, 70, 80, 90, 100, 110 or 120 Ω / sq), preferably 70 to 100 Ω / sq (for example, 70, 80, 90 or 100 Ω / sq).

[0037] In the present invention, it is preferred to use a carbon black film with a smaller square resistance in both the lower super surface layer and the upper super surface layer. The smaller the square resistance, the smaller the square resistance deviation of the carbon black film. As the square resistance value increases, the resistance deviation in the preparation process of the carbon black film gradually increases, and the resistance values ​​of the carbon black films on the upper and lower super surfaces are obtained through the parameter optimization design of the structure. The resistance change will affect the overall absorption performance of the structure, and the high-frequency wave absorption performance is more sensitive to the resistance change. The greater the resistance change, the greater the fluctuation of the curve at the high frequency. In order to reduce the influence of the resistance change on the absorption strength of the structure, the upper and lower super surfaces in the present invention both use a carbon black film with a small resistance.

[0038] According to some preferred embodiments, the thickness of the lower super surface layer and / or the upper super surface layer is 50 to 80 μm, preferably 70 to 80 μm; in the present invention, a product consisting of a substrate and a carbon black film scraped on the substrate can be directly purchased as the base material of the lower super surface layer and the upper super surface layer; in the present invention, the thickness of the etched lower super surface basic unit and the etched upper super surface basic unit is the same as the thickness of the carbon black film; and / or the substrate is made of polyimide (PI) material.

[0039] According to some preferred embodiments, the thickness t0 of the first dielectric layer is 1.3-1.7 mm (for example, 1.3, 1.4, 1.5, 1.6 or 1.7 mm); the thickness t1 of the second dielectric layer is 1.8-2.2 mm (for example, 1.8, 1.9, 2, 2.1 or 2.2 mm); and / or the thickness of the adhesive film layer t2 is 0.08-0.15 mm (for example, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14 or 0.15 mm); the present invention does not specifically limit the adhesive film layer used, and those skilled in the art can make a conventional selection. Preferably, the adhesive film layer can adopt a finished film with high bonding strength and high temperature resistance, that is, it is preferably a high-strength and temperature-resistant adhesive.

[0040] According to some preferred embodiments, the metal layer is made of a metal plate, and preferably, the thickness of the metal layer is 0.2 mm. The present invention does not specifically limit the material used for the metal plate, and those skilled in the art can conventionally select a metal material suitable for an absorbing structure as the metal plate; and / or the first dielectric layer and / or the second dielectric layer is made of PP foam (polypropylene foam) or PMI foam (polymethacrylimide foam).

[0041] According to some preferred embodiments, the total thickness of the ultra-wideband high-performance absorbing structure is less than or equal to 4.3 mm.

[0042] The present invention will be further described below by way of examples, but the protection scope of the present invention is not limited to these embodiments. The present invention may also have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations shall all belong to the protection scope of the claims attached to the present invention. The experimental methods used in the following examples and comparative examples are conventional methods unless otherwise specified. The materials used in the following examples and comparative examples, etc., can be obtained from commercial channels unless otherwise specified.

[0043] Example 1

[0044] This embodiment provides an ultra-wideband high-performance absorbing structure based on a double-layer metasurface, such as Figure 1As shown, from bottom to top, it includes a metal layer, a film layer, a first dielectric layer, a film layer, a lower super surface layer, a film layer, a second dielectric layer, a film layer and an upper super surface layer; wherein the thickness of the metal layer is 0.2 mm, the four film layers are all made of films with a thickness t2 of 0.1 mm, the first dielectric layer is made of PP foam with a thickness t0 of 1.6 mm, the second dielectric layer is made of PP foam with a thickness t1 of 2.0 mm; the lower super surface layer includes a plurality of periodically arranged lower super surface basic units, the lower The basic unit of the super surface is a single annular regular octagon, the longest diagonal l1 of the annular regular octagon is 9 mm, and the width W1 is 2.2 mm. The basic units of the lower super surface are arranged in the same arrangement period in the x direction and the y direction, and the arrangement period is 9 mm. The lower super surface layer is composed of a substrate and a carbon black film arranged on the substrate. The basic units of the lower super surface are etched in the carbon black film. The carbon black film surface in the lower super surface layer is arranged in the direction of the first dielectric layer. The direction of the carbon black film in the lower super surface layer is The resistance is 70Ω / sq, the substrate is made of polyimide material, the thickness of the lower super surface layer is 70μm; the upper super surface layer includes a plurality of periodically arranged upper super surface basic units, the upper super surface basic unit is composed of an outer annular regular octagon and an inner annular regular octagon, and the outer annular regular octagon and the inner annular regular octagon are arranged concentrically, the longest diagonal l2 of the outer annular regular octagon is 7mm, the width W2 is 1mm, the longest diagonal l3 of the inner annular regular octagon is 4mm, the width W 3 is 0.3mm, the upper super surface layer is composed of a substrate and a carbon black film arranged on the substrate, the upper super surface basic units are etched in the carbon black film, the upper super surface basic units are arranged with the same arrangement period in the x direction and the y direction, and the arrangement period is 9mm, the carbon black film in the upper super surface layer is arranged in the direction of the second dielectric layer, the square resistance of the carbon black film in the upper super surface layer is 100Ω / sq, the substrate is made of polyimide material, and the thickness of the upper super surface layer is 70μm.

[0045] Combination Figure 2 As shown in the periodic array form of the absorbing structure designed by the present invention, a flat sample consisting of 20 metasurface basic units in the horizontal direction (x direction) and the vertical direction (y direction) is manufactured, and the sample size is 180mm×180mm; when the electromagnetic wave signal is vertically incident from the upper metasurface layer to the metal layer, the electromagnetic performance of the sample is tested, and the results are as follows Figure 5 and Figure 6 As shown, Figure 5 and Figure 6The reflection coefficient test curves of the absorbing structure in the present embodiment in the horizontal polarization state and the vertical polarization state are respectively given. It can be seen from the figure that under the two polarization conditions, the absorbing structure exhibits excellent ultra-wideband absorbing performance, indicating that the absorbing structure has the characteristic of being insensitive to the polarization angle of electromagnetic waves. Figure 5 and Figure 6 The middle dotted line shows that the reflection coefficient of the absorbing structure proposed in this embodiment is ≤-10dB in the range of 10GHz to 40GHz, which indicates that the absorbing structure in the present invention has the excellent characteristics of maintaining a large bandwidth and high absorption performance under the condition of a small thickness.

[0046] When 1000 ultra-wideband high-performance absorbing structures based on the double-layer metasurface described in this embodiment were formed, the yield rate (qualified rate) was measured to be 100%. In this embodiment, the reflection coefficient of each absorbing structure obtained in the range of 10GHz to 40GHz is less than or equal to -10dB, which can be considered as a good product.

[0047] Example 2

[0048] Embodiment 2 is substantially the same as Embodiment 1, except that:

[0049] Among them, the upper super surface basic unit is composed of an outer annular regular octagon and an inner annular regular octagon, and the outer annular regular octagon and the inner annular regular octagon are concentrically arranged, the longest diagonal l2 of the outer annular regular octagon is 7mm, and the width W2 is 0.6mm, the longest diagonal l3 of the inner annular regular octagon is 5.6mm, and the width W3 is 0.3mm.

[0050] The ultra-wideband high-performance absorbing structure based on the double-layer metasurface in this embodiment has a reflection coefficient of ≤-7dB in the range of 10GHz to 40GHz. Compared with Example 1, the absorbing performance is significantly weakened.

[0051] Example 3

[0052] Embodiment 3 is substantially the same as Embodiment 1, except that:

[0053] Among them, the square resistance of the carbon black film in the lower super surface layer is 90Ω / sq, and the square resistance of the carbon black film in the upper super surface layer is 120Ω / sq.

[0054] The ultra-wideband high-performance absorbing structure based on the double-layer metasurface in this embodiment has a reflection coefficient of ≤-8dB in the range of 10GHz to 40GHz, and the curve at the low frequency will shift upward. The absorbing performance of this embodiment at the low frequency is poorer than that of embodiment 1.

[0055] When 1000 ultra-wideband high-performance absorbing structures based on the double-layer metasurface described in this embodiment were formed, the yield rate (qualified rate) was measured to be 99.5%. In this embodiment, the reflection coefficient of each absorbing structure obtained in the range of 10GHz to 40GHz is less than or equal to -8dB, which can be considered as a good product.

[0056] Comparative Example 1

[0057] Comparative Example 1 is substantially the same as Example 1, except that:

[0058] The lower super surface basic unit is composed of an outer annular regular octagon and an inner annular regular octagon, and the outer annular regular octagon and the inner annular regular octagon are concentrically arranged, the longest diagonal of the outer annular regular octagon is 9 mm, and the width is 2.2 mm, the longest diagonal of the inner annular regular octagon is 4.3 mm, and the width is 1 mm; the upper super surface basic unit is a single annular regular octagon, the longest diagonal of the annular regular octagon is 4 mm, and the width is 0.3 mm.

[0059] The reflection coefficient of the double-layer metasurface-based absorbing structure in this comparative example is ≤-5dB in the range of 10GHz to 40GHz, and has a greater impact on the absorbing performance at low frequencies.

[0060] Comparative Example 2

[0061] Comparative Example 2 is substantially the same as Example 1, except that:

[0062] The upper super surface basic unit is composed of a single annular regular octagon, the longest diagonal l2 of the single annular regular octagon is 7 mm, and the width W2 is 1 mm.

[0063] The reflection coefficient of the double-layer metasurface-based absorbing structure in this comparative example is ≤-5dB in the range of 10GHz to 40GHz. Only two strong resonances can be excited in this comparative example, resulting in poor absorbing performance between the two resonance peaks, which weakens the absorbing intensity within a large bandwidth.

[0064] Comparative Example 3

[0065] Comparative Example 3 is substantially the same as Example 1, except that:

[0066] The upper super surface basic unit is a single annular regular octagon, the longest diagonal l3 of the single annular regular octagon is 4 mm, and the width W3 is 0.3 mm.

[0067] The reflection coefficient of the double-layer metasurface-based absorbing structure in this comparative example was measured to be ≤-5dB in the range of 10GHz to 40GHz. In this comparative example, only two strong resonances can be excited, and the two resonance peaks are far apart, resulting in poor absorbing performance between the two resonance peaks, which weakens the absorbing intensity within a large bandwidth.

[0068] Comparative Example 4

[0069] This comparative example refers to CN 117335167 A and provides an absorbing structure having a reflection coefficient of less than or equal to -20 dB at a low frequency point f1 (11-14 GHz) and a high frequency point f2 (19-23 GHz) in a broadband absorption band 1, and a low frequency point f3 (29-32 GHz) and a high frequency point f4 (35-38 GHz) in a broadband absorption band 2, and within the above-mentioned band range (f2-f1=7.4 GHz, f4-f3=5.9 GHz).

[0070] When 1000 absorbing structures of this comparative example were formed, the measured yield rate (qualified rate) was only 97%. In this comparative example, the obtained absorbing structures had a reflection coefficient of less than or equal to -20 dB at the low frequency point f1 (11-14 GHz) and high frequency point f2 (19-23 GHz) of the broadband absorption band 1, the low frequency point f3 (29-32 GHz) and high frequency point f4 (35-38 GHz) of the broadband absorption band 2, and within the above-mentioned band range (f2-f1=7.4 GHz, f4-f3=5.9 GHz), which means that they can be considered as good products.

[0071] Parts of the present invention that are not described in detail are well known to those skilled in the art.

[0072] 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 it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ultra-wideband high-performance absorbing structure based on a double-layer metasurface, characterized in that: The ultra-wideband high-performance wave absorbing structure based on the double-layer metasurface includes, from bottom to top, a metal layer, a film layer, a first dielectric layer, a film layer, a lower metasurface layer, a film layer, a second dielectric layer, a film layer and an upper metasurface layer; The lower super surface layer includes a plurality of periodically arranged lower super surface basic units, each of which is an annular regular octagon. The upper super surface layer includes a plurality of periodically arranged upper super surface basic units, each of which is composed of two inner and outer annular regular octagons of different sizes.

2. The ultra-wideband high-performance absorbing structure according to claim 1, characterized in that: The longest diagonal line l1 of the lower super surface basic unit is 8.5-9.5 mm, and the width W1 is 2.0-2.5 mm.

3. The ultra-wideband high-performance absorbing structure according to claim 1, characterized in that: The upper super surface basic unit is composed of an outer annular regular octagon and an inner annular regular octagon, and the outer annular regular octagon and the inner annular regular octagon are arranged concentrically; The longest diagonal l2 of the outer annular regular octagon is 6.5 to 7.3 mm, and the width W2 is 0.8 to 1.3 mm; The longest diagonal line l3 of the inner annular regular octagon is 3.5 to 4.5 mm, and the width W3 is 0.2 to 0.6 mm.

4. The ultra-wideband high-performance absorbing structure according to claim 1, characterized in that: The lower super surface layer is composed of a substrate and a carbon black film arranged on the substrate, and the lower super surface basic unit is etched in the carbon black film; The upper super surface layer is composed of a substrate and a carbon black film arranged on the substrate, and the upper super surface basic unit is etched in the carbon black film; The lower super surface basic units and the upper super surface basic units are arranged with the same arrangement period in the x direction and the y direction, and the arrangement period is 9 mm.

5. The ultra-wideband high-performance absorbing structure according to claim 4, characterized in that: The carbon black film surface in the lower super surface layer is arranged toward the first dielectric layer; The carbon black film surface in the upper super surface layer is arranged toward the second medium layer.

6. The ultra-wideband high-performance absorbing structure according to claim 4, characterized in that: The sheet resistance of the carbon black film in the lower super surface layer is 40 to 70 Ω / sq; and / or The square resistance of the carbon black film in the upper super surface layer is 70 to 120 Ω / sq, preferably 70 to 100 Ω / sq.

7. The ultra-wideband high-performance absorbing structure according to claim 1, characterized in that: The thickness of the lower super surface layer and / or the upper super surface layer is 50 to 80 μm; and / or The substrate is made of polyimide material.

8. The ultra-wideband high-performance absorbing structure according to claim 1, characterized in that: The thickness t0 of the first dielectric layer is 1.3-1.7 mm; The thickness t1 of the second dielectric layer is 1.8-2.2 mm; and / or The thickness of the adhesive film layer t2 is 0.08-0.15 mm.

9. The ultra-wideband high-performance absorbing structure according to claim 1, characterized in that: The metal layer is made of a metal plate; and / or The first medium layer and / or the second medium layer is made of PP foam or PMI foam.

10. The ultra-wideband high-performance absorbing structure according to any one of claims 1 to 9, characterized in that: The total thickness of the ultra-wideband high-performance absorbing structure is less than or equal to 4.3 mm.

Images