Huygens metasurface-based double-layer broadband wave-absorbing metamaterial and preparation method thereof
By combining Huygens metasurface arrays with lossy coatings, the problem of insufficient absorption performance of existing absorbing materials in complex environments is solved, achieving wideband and high-efficiency electromagnetic wave absorption, which is suitable for a variety of application scenarios.
Patent Information
- Application Number
- CN202511060698.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-30
- Publication Date
- 2025-10-28
AI Technical Summary
Existing microwave absorbing materials are difficult to meet the requirements of high microwave absorption performance in complex environments, especially the problem of electromagnetic wave reflection caused by different dielectric impedances. Traditional impedance matching layers have limited effect on lossy electromagnetic waves.
By using a Huygens metasurface as an impedance matching layer, combined with a lossy coating and a total reflection backplane, wavefront modulation is achieved through the design of a Huygens metasurface array, thereby enhancing the absorption performance of electromagnetic waves.
It significantly improves absorption performance over a wide frequency range, broadens the effective absorption bandwidth, and enhances the ability to dissipate electromagnetic waves, making it suitable for complex or harsh environments.
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Figure CN120854928A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of electromagnetic functional composite materials technology, specifically relating to a double-layer broadband electromagnetic wave absorbing device based on an artificial metasurface structure and its preparation method. Background Technology
[0002] In the information age, the widespread application of electromagnetic waves has brought great convenience to our lives. However, excessive electromagnetic radiation not only has adverse effects on health, but can also cause signal interference between different electronic devices, leading to malfunctions. Absorbing materials can reduce electromagnetic radiation by absorbing waves. Common absorbing materials (lossy coatings) include ferrites, carbon black, and conductive polymers, which have good absorption properties. However, they are insufficient to meet the high absorption performance requirements of electromagnetic waves in complex environments, such as stringent requirements on thickness and weight. In particular, when electromagnetic waves reach the interface from the air, reflection occurs due to the difference in impedance between the media, causing a decrease in the absorption performance of the lossy coating. Furthermore, traditional impedance matching layers made of transparent materials have limited effect on lossy electromagnetic waves and are not used for absorption, thus failing to meet the aforementioned requirements. Summary of the Invention
[0003] This invention aims to solve the above-mentioned problems by using a Huygens metasurface double-layer surface array to achieve wavefront modulation, reduce interface reflection, and enable the absorbing material placed under the metasurface to absorb waves over a wide frequency range, thereby greatly improving the absorption performance and enhancing the ability to dissipate electromagnetic waves.
[0004] The double-layer broadband absorbing metamaterial based on Huygens metasurface according to the embodiments of this application includes Huygens metasurface, lossy coating and total reflection backplate, wherein the lossy coating is disposed between Huygens metasurface and total reflection backplate.
[0005] The Huygens metasurface includes a dielectric substrate, which includes a first surface and a second surface opposite to each other. The first surface is provided with a first Huygens metasurface array, and the second surface is provided with a second Huygens metasurface array.
[0006] According to the Huygens metasurface-based double-layer broadband absorbing metamaterial in the embodiments of this application, the first Huygens metasurface array is periodically arranged from unit structures. Each unit structure includes a first conductive thin film and a second conductive thin film with a certain length. The first conductive thin film and the second conductive thin film are perpendicular to each other, and the center positions of the first conductive thin film and the second conductive thin film are connected to each other along their length.
[0007] The second Huygens metasurface array is composed of periodically arranged unit structures. Each unit structure includes a third conductive thin film and a fourth conductive thin film with a certain length. The third and fourth conductive thin film are perpendicular to each other, and a first separation gap is provided at the center of the length of the third conductive thin film and a second separation gap is provided at the center of the length of the fourth conductive thin film.
[0008] According to the Huygens metasurface-based double-layer broadband absorbing metamaterial in the embodiments of this application, the conductive thin film has a length of 9~12mm, a width of 0.2~0.5mm, and a separation gap length of 1.2~1.7mm.
[0009] According to the Huygens metasurface-based double-layer broadband absorbing metamaterial in the embodiments of this application, the thickness of the Huygens metasurface is 3.4-3.8 mm, the thickness of the loss coating is 3-5 mm, and the thickness of the total reflection backplate is 1.0-2.0 mm.
[0010] According to the embodiments of this application, the double-layer broadband absorbing metamaterial based on Huygens metasurface has an absorption bandwidth of 5.2GHz~7.97GHz.
[0011] According to the embodiment of this application, the double-layer broadband absorbing metamaterial based on Huygens metasurface has an absorption bandwidth of 7.97 GHz and an effective absorption range of 8.47~11.45 GHz and 13.01~18 GHz.
[0012] According to the Huygens metasurface-based double-layer broadband absorbing metamaterial in the embodiments of this application, the average reflection loss is -13.08dB and the maximum reflection loss is -20.56dB.
[0013] According to the Huygens metasurface-based double-layer broadband absorbing metamaterial in the embodiments of this application, the material of the conductive thin film is selected from any one or a combination of carbon-based conductive films, transparent conductive oxide films, and conductive polymer films.
[0014] According to the Huygens metasurface-based double-layer broadband absorbing metamaterial in the embodiments of this application, the sheet resistance of the conductive thin film is 1~15Ω / sq.
[0015] According to the Huygens metasurface-based bilayer broadband absorbing metamaterial in the embodiments of this application, the dielectric substrate includes a matrix and fibers disposed inside the matrix.
[0016] According to the Huygens metasurface-based double-layer broadband absorbing metamaterial in the embodiments of this application, the fiber material is selected from any one or a combination of quartz fiber cloth, aramid fiber cloth, glass fiber cloth, and ultra-high molecular weight polyethylene fiber cloth.
[0017] According to the Huygens metasurface-based double-layer broadband absorbing metamaterial in the embodiments of this application, the dielectric constant of the dielectric substrate is 2.4 to 3.2, and the thickness of the dielectric substrate is 3.4 to 3.8 mm.
[0018] According to the Huygens metasurface-based bilayer broadband absorbing metamaterial in the embodiments of this application, the loss coating includes an electrically conductive coating.
[0019] According to the Huygens metasurface-based bilayer broadband absorbing metamaterial in the embodiments of this application, the loss coating comprises a conductive polymer or a carbon material.
[0020] According to the Huygens metasurface-based bilayer broadband absorbing metamaterial in the embodiments of this application, the carbon material includes carbon black or graphene.
[0021] According to the Huygens metasurface-based bilayer broadband absorbing metamaterial in the embodiments of this application, the loss coating includes a magnetic coating.
[0022] According to the Huygens metasurface-based bilayer broadband absorbing metamaterial in the embodiments of this application, the magnetic coating is selected from magnetic metal micropowder.
[0023] According to the Huygens metasurface-based bilayer broadband absorbing metamaterial in the embodiments of this application, the magnetic coating is selected from carbonyl ferromagnetic metal micropowder or ferrite magnetic metal micropowder.
[0024] According to the Huygens metasurface-based double-layer broadband absorbing metamaterial in the embodiments of this application, the material of the total reflection backplate is selected from carbon fiber reinforced resin matrix composite material or conductive metal.
[0025] Beneficial effects: Electromagnetic waves are reflected from the air to the interface due to the difference in impedance between the media. The double-layer broadband absorbing metamaterial based on Huygens metasurface prepared in this invention uses Huygens metasurface as an impedance matching layer. Although it does not have the ability to absorb waves itself, it has an impedance that is closer to that of air, which gives it the ability to modulate the wavefront. When used on a lossy coating, it can meet the impedance matching conditions, so that electromagnetic waves are reflected very little from the air to the interface. This allows the incident electromagnetic waves to enter the lossy coating as much as possible and be absorbed, thereby enhancing the absorption performance of the lossy coating and improving the ability to dissipate electromagnetic waves.
[0026] Based on the above, the double-layer broadband absorbing metamaterial of this invention has a large effective absorption bandwidth in the X-band (8~12GHz) and Ku-band (12~18GHz). Specifically, this invention effectively absorbs in the ranges of 8.47~11.45GHz and 13.01~18GHz, with an effective absorption bandwidth of 7.97GHz. Figure 7 As shown in the figure, this demonstrates the improvement in its wave absorption performance.
[0027] Based on the above, the average reflection loss of the double-layer broadband absorbing metamaterial of the present invention is -13.08 dB, and the maximum reflection loss is -20.56 dB. Figure 7 As shown in the figure, this demonstrates the improvement in its wave absorption performance.
[0028] Based on the above, the present invention further utilizes a specific patterned metasurface array on top of an existing lossy coating. The Huygens metasurface used has a small thickness, and the increase in the thickness of the absorbing material caused by the metasurface is also small, but it greatly improves the absorption performance. This allows the present invention to still be used in complex or harsh environments with good absorption performance. Attached Figure Description
[0029] Figure 1 This is a schematic diagram of the three-dimensional structure of the double-layer microwave absorbing composite material.
[0030] Figure 2 This is a schematic diagram of the cross-shaped structure on the top layer of the Huygens metasurface.
[0031] Figure 3 This is a schematic diagram of the hollow cross structure at the bottom layer of the Huygens metasurface.
[0032] Figure 4 This is the Huygens resonance normalized surface resistivity and magnetoresistance balance condition.
[0033] Figure 5 The results are from Huygens metasurface reflection and transmission simulations.
[0034] Figure 6 The results of reflection loss calculation, simulation and experimental comparison for lossy coatings are presented.
[0035] Figure 7 The simulation results are compared between the double-layer absorbing composite material and the single-layer lossy material.
[0036] Figure 8 The reflection loss phase (a) and group delay (b) of the loss coating are shown.
[0037] Figure 9 The reflection loss phase (a) and group delay (b) of the double-layer absorbing composite material are shown.
[0038] Figure 10 The Smith chart shows the impedance of the lossy coating.
[0039] Figure 11 This is the Smith chart of the double-layer absorbing composite material. Detailed Implementation
[0040] The technical solution of the present invention will be further described clearly and completely below with reference to specific embodiments, but it is not limited to the embodiments described below.
[0041] This invention provides a bilayer electromagnetic wave absorbing composite material based on Huygens metasurface. By using Huygens metasurface as an impedance matching layer to satisfy the impedance matching condition, incident electromagnetic waves can enter the loss coating as much as possible and be absorbed, which greatly enhances the wave absorption performance of the loss coating. In addition, the composite structure has a novel design, simple preparation process, low cost, and is easy to realize, and has a certain degree of universality.
[0042] like Figure 1 As shown, the bilayer broadband absorbing metamaterial based on Huygens metasurfaces comprises a Huygens metasurface in the upper layer, a lossy coating in the middle layer, and a total reflection backplane in the lower layer. From top to bottom, the Huygens metasurfaces are: a first Huygens metasurface array with a periodic pattern of cross-shaped conductive thin film structure in the top layer, a dielectric substrate in the middle layer, and a second Huygens metasurface array with a periodic pattern of hollow cross-shaped conductive thin film structure in the bottom layer.
[0043] The cross-shaped conductive thin film structure of the periodic pattern on the top layer of the Huygens metasurface consists of a group of mutually perpendicular and equally spaced elongated conductive thin films, with a length of 9–12 mm and a width of 0.2–0.5 mm. The hollow cross-shaped conductive thin film structure of the periodic pattern on the bottom layer of the Huygens metasurface is also composed of a group of mutually perpendicular and equally spaced elongated conductive thin film structures, obtained by removing a square hole at their geometric center. The strips have a length of 9–12 mm and a width of 0.2–0.5 mm, and the width of the square hole is 1.2–1.7 mm.
[0044] The materials used in the cross-shaped conductive thin film structure and the hollow cross-shaped conductive thin film structure are selected from conductive thin films, with a sheet resistance of 1~15Ω / sq. In one embodiment, the materials used in the cross-shaped structure and the hollow cross-shaped structure are selected from any one of carbon-based conductive thin films, transparent conductive oxide thin films, and conductive polymer thin films.
[0045] In this array, the arrangement patterns of the first and second Huygens metasurface arrays are centrally symmetrical. The first and second Huygens metasurface arrays are arranged vertically opposite each other, with a consistent distribution. The first conductive thin film elements of each unit structure in the first Huygens metasurface array are connected sequentially in the horizontal direction, and the second conductive thin film elements of each unit structure are connected sequentially in the vertical direction. Similarly, the third conductive thin film elements of each unit structure in the second Huygens metasurface array are connected sequentially in the horizontal direction, and the fourth conductive thin film elements of each unit structure are connected sequentially in the vertical direction.
[0046] The dielectric substrate includes a matrix and fibers disposed within the matrix. The limiting material of the dielectric substrate is one or more fiber materials selected from fiber-reinforced resin matrix composites, such as quartz fiber cloth, aramid fiber cloth, glass fiber cloth, and ultra-high molecular weight polyethylene fiber cloth. The matrix material is epoxy resin. The dielectric constant of the dielectric substrate is 2.4–3.2, and the thickness of the Huygens metasurface is 3.4–3.8 mm. It can be understood that, due to the very thin conductive film, the thickness of the Huygens metasurface is essentially equivalent to the thickness of the dielectric substrate.
[0047] In the above scheme, the connection between the pattern layer, dielectric layer, and reflective layer is preferably achieved through an epoxy resin film. The cross structure and the hollow cross structure are fixed on a quartz fiber reinforced epoxy resin substrate; however, other dielectric substrates with different dielectric constants can be selected as needed.
[0048] In this invention, the dielectric substrate of the Huygens metasurface is prepared using a quartz fiber reinforced epoxy resin composite material. The preparation method of the Huygens metasurface is as follows: S1. Mix epoxy resin and curing agent evenly to obtain resin solution.
[0049] S2. After cleaning the mold and applying a release agent, lay a layer of cut quartz fiber cloth on the surface of the mold, coat it with epoxy resin through thermosetting or RTM process, lay another layer of quartz fiber cloth, and coat it with epoxy resin through the above method. Repeat the above steps until the dielectric layer reaches about half the thickness of the dielectric substrate.
[0050] S3. The topmost layer of the dielectric layer is covered with quartz fiber cloth, and the cut carbon fiber felt (carbon conductive film) is laid on it. The carbon fiber felt is then attached to the surface of the dielectric layer by molding thermosetting or RTM process to obtain a carbon fiber felt / quartz fiber reinforced epoxy resin composite material board.
[0051] S4. The carbon fiber felt (carbon conductive film) of the substrate is laser-engraved or CNC-processed. In the laser-processed or CNC-processed part, the carbon fiber felt is exposed to the substrate by glass to form the above-mentioned first Huygens metasurface array pattern, and a first dielectric layer with a thickness of half the thickness of the dielectric substrate is obtained.
[0052] S5. Repeat steps S2 to S4 above to obtain a second dielectric layer with a thickness of half that of the dielectric substrate and having a second Huygens metasurface array.
[0053] S6. Cut the first dielectric layer and the second dielectric layer into 180×180mm pieces, and combine the first dielectric layer and the second dielectric layer by epoxy film or molding process to obtain a Huygens metasurface with different periodic patterns on both sides.
[0054] In this invention, the method for preparing the loss coating is as follows: S1. 20L of graphene oxide stock solution was rapidly stirred under ultrasonic dispersion assistance to improve its sedimentation effect. The obtained graphene oxide solution was freeze-dried and then microwaved at 700w for 4s to obtain approximately 50g of flocculent reduced graphene oxide powder.
[0055] S2. Weigh 100g of epoxy resin and 80g of curing agent and heat at 80℃ for 90min until liquid. Mix and add 0.5g of accelerator. Add 3.24g of reduced graphene oxide powder to the epoxy resin. After heating in a water bath at 80℃ and stirring at 200 rpm for 20min, the desired reduced graphene oxide / epoxy resin composite system is obtained.
[0056] S3. The reduced graphene oxide / epoxy resin composite system is compounded with 70g of ultra-high molecular weight polyethylene fiber, and the desired loss coating is obtained through thermosetting or molding processes.
[0057] The graphene oxide was stirred at a speed of 300–600 r / min for 40–60 minutes. The ultra-high molecular weight polyethylene fiber was 180–200 mm in size. The mass fraction of reduced graphene oxide was 1%–2%. The thickness of the lossy coating was 3–5 mm.
[0058] In this invention, the reflective substrate material is a self-conductive metal or carbon fiber composite material.
[0059] This invention combines a Huygens metasurface and a dielectric loss coating to create an ultrathin absorbing composite material capable of broadband absorption. The Huygens metasurface, with its low reflection and high transmission characteristics, serves as a matching layer, providing excellent impedance matching for the entire composite structure and enhancing electromagnetic wave attenuation in the low-frequency region. The coating's electromagnetic wave absorption capability also promotes the Huygens metasurface's absorption in the high-frequency region. The synergistic effect between the two significantly broadens the absorption bandwidth and enhances the absorption performance of the composite structure. The proposed double-layer absorbing material not only achieves broadband absorption at a thin thickness but also has a simple structure suitable for mass production, demonstrating promising application prospects.
[0060] This invention utilizes a centrally symmetrical, double-sided cross-shaped Huygens metasurface unit. Under electromagnetic wave incidence, this unit excites orthogonally balanced electrical and magnetic responses. At this point, the dispersion curves of the electric and magnetic polarizations are similar, resulting in low reflection and high transmission over a wide frequency range. As a matching layer, the Huygens metasurface not only provides excellent impedance matching for the composite absorbing material but also generates a magnetic field converging effect at the bottom. This electromagnetic property enhances the attenuation of the loss coating in the low-frequency region.
[0061] The strong absorption capability of the coating in this invention also greatly promotes the absorption of the Huygens metasurface in the high-frequency region, and the synergistic effect between the two greatly broadens the effective absorption bandwidth. Each long strip structure contained in the double-sided cross can be regarded as a resonant strip, which can generate inductive-capacitive resonance. When an incident plane wave is incident on the Huygens metasurface along the direction parallel to the pattern, the cross pattern distributed on both sides of the medium is excited to generate a discontinuous field. At this time, the surface current and the surface magnetic current are orthogonally balanced, thus generating Huygens resonance. Figure 4 This result induces the ultrawideband low-reflection, high-transmission properties of Huygens metasurfaces, producing weak absorption only at one frequency, such as... Figure 5 As shown.
[0062] In one example, the prepared loss coating has a size of 180mm × 180mm × 3.3mm, and the Huygens metasurface has a size of 180mm × 180mm × 3.6mm.
[0063] Band description: X-band (8~12GHz), Ku-band (12~18GHz).
[0064] like Figure 7 As shown, MAM represents loss coating, QF represents dielectric substrate, and HMS represents Huygens metasurface.
[0065] For MAM, based on the multilayer transmission line theory, its theoretical effective absorption bandwidth (RL≤-10dB) is calculated to be 8.46~14.08GHz, with a total effective absorption bandwidth of 5.62GHz. Figure 6 ).
[0066] Using the CST Microwave Studio module of the electromagnetic compatibility simulation software, periodic simulation boundary conditions were set, and the effective absorption bandwidth (RL≤-10dB) was obtained as 8.37~13.57GHz, with a total finite absorption bandwidth of 5.2GHz. Figure 6 , Figure 7 The simulation results are shown.
[0067] Experimental tests revealed an effective absorption bandwidth (RL≤-10dB) of 8.68GHz~13.4GHz, with a total finite absorption bandwidth of 4.72GHz. Figure 6 ).
[0068] like Figure 7 The calculated average reflection loss of the MAM is -8.89dB, and the maximum reflection loss is -37.28dB.
[0069] For QF+MAM, such as Figure 7As shown, its theoretical effective absorption bandwidth (RL≤-10dB) is 12.53~18GHz, with a total effective absorption bandwidth of 5.47GHz. The calculated average reflection loss is -9.67GHz, and the maximum reflection loss is -31.06dB.
[0070] This invention, HMS+MAM, such as Figure 7 As shown, the effective absorption bandwidth (RL≤-10dB) is 8.47~11.45GHz and 13.01~18GHz, with a total 7.97GHz finite absorption bandwidth. The average reflection loss reaches -13.08dB, and the maximum reflection loss is -20.56dB.
[0071] This invention combines a Huygens metasurface with a lossy coating. Compared to a single lossy layer, the thickness increases by 3.6 mm, but it achieves effective absorption in the ranges of 8.47~11.45 GHz and 13.01~18 GHz, with an effective absorption bandwidth of 7.97 GHz, almost covering the X-band (8~12 GHz) and Ku-band (12~18 GHz). The effective bandwidth is more than 1.4 times that of MAM and QF+MAM, and the total thickness of the Huygens metasurface and lossy layer composite is only about 8 mm.
[0072] Comparison of reflection loss, phase, and group delay between MAM and HMS+MAM ( Figure 8 and Figure 9 This indicates that the Huygens metasurface enhances electromagnetic resonance and promotes the inherent absorption of the loss coating for HMS+MAM.
[0073] Comparison of Smith impedance circle plots for MAM and HMS+MAM ( Figure 10 and Figure 11 The results show that the curves based on the Huygens metasurface absorbing structure are mostly located within the matching circle, further illustrating that the impedance matching of HMS+MAM is significantly improved. Therefore, more electromagnetic waves enter the bottom coating and are lost rather than reflected.
[0074] As described above, the double-layer absorbing composite material prepared by this invention exhibits excellent absorbing material characteristics such as broadband and strong absorption at subwavelength thickness. Although the Huygens metasurface itself does not possess absorbing properties, its role as a matching layer not only provides good impedance matching, but also, due to the strong absorption capability of the coating, promotes high-frequency absorption of the Huygens metasurface. The combination of these two enhances the absorption performance. The effective absorption bandwidth of the lossy coating at the bottom of the Huygens metasurface is increased from 5.62 GHz to 7.97 GHz. The structural unit design used in this invention is novel. Compared with other Huygens metasurfaces previously proposed, it can achieve orthogonal balance between electrical and magnetic responses on a single structure. The designed Huygens metasurface exhibits low reflection and high transmission characteristics in the 2–18 GHz frequency band. In the military field, the double-layer absorbing composite material of this invention can be used on the outer surfaces of aircraft, military vehicles, and facilities, effectively reducing the radar cross-section and achieving radar stealth. In the civilian field, it can be used in microwave anechoic chambers, electromagnetic compatibility, 5G, and other fields.
[0075] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0076] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0077] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0078] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.
[0079] In this invention, the term "and / or" describes the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following associated objects are in an "or" relationship. "At least one" refers to one or more; "at least one of A and B," similar to "A and / or B," describes the relationship between associated objects, indicating that three relationships can exist. For example, at least one of A and B can represent: A alone, A and B simultaneously, or B alone.
[0080] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0081] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A bilayer broadband absorbing metamaterial based on Huygens metasurface, characterized in that, It includes a Huygens metasurface, a lossy coating, and a total reflection backplate, wherein the lossy coating is disposed between the Huygens metasurface and the total reflection backplate; The Huygens metasurface includes a dielectric substrate, which includes a first surface and a second surface opposite to each other. The first surface is provided with a first Huygens metasurface array, and the second surface is provided with a second Huygens metasurface array.
2. The bilayer broadband absorbing metamaterial based on Huygens metasurface according to claim 1, characterized in that, The first Huygens metasurface array is composed of periodically arranged unit structures. Each unit structure includes a first conductive thin film and a second conductive thin film with a certain length. The first conductive thin film and the second conductive thin film are perpendicular to each other, and the center positions of the first conductive thin film and the second conductive thin film are connected to each other along their length. The second Huygens metasurface array is composed of periodically arranged unit structures. Each unit structure includes a third conductive thin film and a fourth conductive thin film with a certain length. The third and fourth conductive thin film are perpendicular to each other, and a first separation gap is provided at the center of the length of the third conductive thin film and a second separation gap is provided at the center of the length of the fourth conductive thin film.
3. The bilayer broadband absorbing metamaterial based on Huygens metasurface according to claim 2, characterized in that, The conductive thin film component has a length of 9~12mm, a width of 0.2~0.5mm, and a separation gap length of 1.2~1.7mm.
4. The bilayer broadband absorbing metamaterial based on Huygens metasurface according to claim 2, characterized in that, The Huygens metasurface has a thickness of 3.4–3.8 mm, the loss coating has a thickness of 3–5 mm, and the total reflection backplate has a thickness of 1.0–2.0 mm.
5. The bilayer broadband absorbing metamaterial based on Huygens metasurface according to any one of claims 1-5, characterized in that, The absorption bandwidth is 5.2GHz~7.97GHz.
6. The bilayer broadband absorbing metamaterial based on Huygens metasurface according to any one of claims 1-5, characterized in that, The absorption bandwidth is 7.97 GHz, and the effective absorption range is 8.47~11.45 GHz and 13.01~18 GHz.
7. The bilayer broadband absorbing metamaterial based on Huygens metasurface according to any one of claims 1-5, characterized in that, The average reflection loss is -13.08dB, and the maximum reflection loss is -20.56dB.
8. The bilayer broadband absorbing metamaterial based on Huygens metasurface according to any one of claims 1-5, characterized in that, The material of the conductive thin film is selected from any one or a combination of carbon-based conductive films, transparent conductive oxide films, and conductive polymer films. More preferably, the sheet resistance of the conductive thin film is 1~15Ω / sq; Preferably, the dielectric substrate includes a matrix and fibers disposed inside the matrix; More preferably, the fiber material is selected from any one or a combination of quartz fiber cloth, aramid fiber cloth, glass fiber cloth, and ultra-high molecular weight polyethylene fiber cloth; More preferably, the dielectric constant of the dielectric substrate is 2.4 to 3.2, and the thickness of the dielectric substrate is 3.4 to 3.8 mm.
9. The bilayer broadband absorbing metamaterial based on Huygens metasurface according to any one of claims 1-5, characterized in that, The loss coating includes a conductive coating; Preferably, the loss coating comprises a conductive polymer or a carbon material; More preferably, the carbon material includes carbon black or graphene; Preferably, the loss coating includes a magnetic coating; More preferably, the magnetic coating is selected from magnetic metal micropowder; More preferably, the magnetic coating is selected from carbonyl ferromagnetic metal micropowder or ferrite magnetic metal micropowder.
10. The bilayer broadband absorbing metamaterial based on Huygens metasurface according to any one of claims 1-5, characterized in that, The material of the total reflection backplate is selected from carbon fiber reinforced resin matrix composites or conductive metals.