A reconfigurable absorbing metasurface based on heterogeneous absorbing units and interlocking tenon and mortise joints

Abstract

This invention discloses a reconfigurable absorbing metasurface based on heterogeneous absorbing units using a tenon-and-mortise interlocking structure, and its configuration method, belonging to the field of electromagnetic wave absorption and metasurface structure technology. The metasurface is formed by assembling multiple lightweight absorbing units through a tenon-and-mortise interlocking structure. The absorbing units use melamine foam, PMI foam, polyurethane foam, or aerogel porous framework materials as the matrix, and are loaded with absorbing components such as graphene, carbon nanotubes, MXene, ferrite particles, carbonyl iron particles, or conductive polymers. The tenon-and-mortise connection structure has multiple levels of insertion positions and limiting structures, allowing adjacent units to form different insertion states, thereby adjusting the unit spacing, air layer thickness, array period, and equivalent electromagnetic parameters, achieving reconfigurable control of the absorption frequency band and response characteristics. Furthermore, heterogeneous absorbing units with different geometries and absorption parameters can be optimized through parametric design and electromagnetic simulation to form planar or curved broadband absorbing structures. This invention combines the advantages of lightweight, modularity, detachability, surface adaptability, and wideband absorption, and can be applied to fields such as electromagnetic stealth, radar absorption, electromagnetic protection, and complex curved electronic equipment.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic wave absorption and metasurface structure technology, specifically relating to a mortise and tenon interlocking wave-absorbing metasurface structure with adjustable electromagnetic response and its configuration method. Background Technology

[0002] As communication equipment, radar systems, and high-end electronic equipment develop towards broadband, lightweight, and complex curved surfaces, electromagnetic wave absorbing structures not only need to meet the absorption performance requirements within specific frequency bands, but also need to consider engineering application needs such as lightweighting, reconfigurability, and adaptation to complex surfaces. Especially in scenarios such as aircraft skin, electromagnetic stealth structures, and detachable electromagnetic protection systems, traditional integral absorbing structures, due to their large mass, high structural rigidity, and limited maintainability, are difficult to meet the application requirements for structural flexibility under complex working conditions.

[0003] In existing technologies, electromagnetic wave absorption structures typically employ monolithic filling materials, layered composite structures, or periodic array structures to achieve electromagnetic wave absorption. These structures generally have fixed electromagnetic parameters after design, making it difficult to adjust their absorption frequency band and response characteristics during subsequent use. When the target frequency band changes, it is often necessary to redesign the structural parameters and re-process the entire sample, resulting in a long design cycle and poor structural reusability.

[0004] On the other hand, while some modular absorbing structures can be partially spliced ​​or replaced, their connection relationships are usually fixed, focusing more on mechanical stability and less on the impact of changes in connection status on the structure's equivalent electromagnetic parameters and absorbing response characteristics. Therefore, existing assembled structures cannot achieve active adjustment of the absorbing frequency band and response characteristics through module arrangement.

[0005] Therefore, existing technologies still lack a modular absorbing structure that combines lightweight design, reconfigurability, surface adaptation, and adjustable electromagnetic response. In particular, there is a lack of a reconfigurable absorbing metasurface system that can adjust the spacing, arrangement, and equivalent electromagnetic parameters of different absorbing units by varying the connection relationships between them. This makes it difficult to meet the application requirements for broadband absorption, rapid reconfiguration, and engineering adaptation in complex electromagnetic environments.

[0006] Therefore, it is necessary to propose a reconfigurable absorbing metasurface based on heterogeneous absorbing units using a tenon-and-mortise interlocking structure and its configuration method. This structure, through a tenon-and-mortise interlocking structure with multiple connection states, allows absorbing units with different geometries and absorption parameters to be quickly assembled according to a predetermined arrangement. Furthermore, by changing the connection states of the units, the spacing between the units and the equivalent electromagnetic parameters of the structure can be adjusted, thereby achieving regulation of the absorption frequency band and response characteristics. Simultaneously, this structure can also meet the engineering application requirements of lightweight design, reusable assembly and disassembly, adaptation to complex curved surfaces, and large-area splicing. Summary of the Invention

[0007] 1. Objective of this invention

[0008] This invention aims to provide a mortise-and-tenon interlocking microwave absorbing metasurface structure with adjustable electromagnetic response and its configuration method. By employing a mortise-and-tenon interlocking assembly strategy with multiple connection states, the spatial arrangement and equivalent electromagnetic parameters between absorbing units can be adjusted, thereby controlling the absorption frequency band and response characteristics. This invention integrates lightweight absorbing units with the mortise-and-tenon interlocking structure, enabling the structure to possess microwave absorption functionality while also being modular, detachable, and reconfigurable, adaptable to complex curved surfaces and large-area assembly scenarios. Furthermore, this invention adjusts the unit spacing, periodic structure, and equivalent electromagnetic parameters by changing the mortise-and-tenon connection state, insertion position, or unit arrangement, thereby forming different electromagnetic response modes, providing a new approach to constructing switchable frequency band absorbing structures and reconfigurable electromagnetic metasurfaces. In addition, this invention can combine heterogeneous absorbing units with different geometries and absorption parameters for combined configurations, and construct target absorbing structures using simulation optimization or parametric design methods, providing a new approach to reconfigurable electromagnetic metasurfaces and broadband absorbing structures.

[0009] 2. Key Invention Points of this Technology

[0010] This invention relates to the protection of a mortise-and-tenon interlocking microwave absorbing metasurface structure with adjustable electromagnetic response and its configuration method. The mortise-and-tenon interlocking microwave absorbing metasurface structure is formed by assembling multiple modular microwave absorbing units, wherein each microwave absorbing unit includes a lightweight microwave absorbing sponge matrix and a mortise-and-tenon connection structure disposed at the edge of the unit; the lightweight microwave absorbing sponge matrix includes melamine foam, PMI foam, polyurethane foam, aerogel porous framework material, or honeycomb lightweight material, and the microwave absorbing sponge is internally loaded with microwave absorbing components, which include carbon-based materials, magnetic particles, MXene materials, conductive polymers, or composite systems thereof.

[0011] The mortise and tenon connection structure includes a tenon and a corresponding groove. The tenon has multiple insertion positions, limiting steps, or graded locking structures, while the groove has a corresponding limiting area, allowing adjacent absorbing units to form different connection states. Different connection states correspond to different unit spacing, arrangement, and periodic structures, thus endowing the absorbing metasurface with different equivalent dielectric parameters, impedance matching characteristics, and electromagnetic propagation paths. These factors further affect the propagation, scattering, reflection, and dissipation processes of electromagnetic waves within the structure, thereby achieving adjustment of the absorption frequency band and response characteristics. Therefore, the mortise and tenon interlocking absorbing metasurface structure combines lightweight, modularity, reconfigurability, and adjustable electromagnetic response. Its multi-state connection strategy also helps to achieve synergistic control of structural function and absorption performance.

[0012] The key points of this invention are as follows:

[0013] (1) Preparation of microwave absorbing unit A: Select lightweight porous sponge material as the main body of the microwave absorbing unit. The lightweight porous sponge material includes melamine foam, PMI foam, polyurethane foam or aerogel porous skeleton material; cut and process it into rectangular, hexagonal, trapezoidal or arc-shaped unit structures. Then, microwave absorbing components are introduced into the interior of the lightweight porous sponge by impregnation, spraying, vacuum filtration, in-situ growth or solution loading, thereby forming a lightweight microwave absorbing unit with electromagnetic wave loss capability.

[0014] Furthermore, the absorbing component includes one or more of graphene, carbon nanotubes, reduced graphene oxide, carbon black, MXene, ferrite particles, carbonyl iron particles, nickel-based particles, or conductive polymers; the absorbing component forms a conductive network or magnetic loss network inside the lightweight sponge skeleton to enhance the electromagnetic wave energy dissipation capability.

[0015] Subsequently, a mortise and tenon joint structure is formed at the edge of the wave-absorbing unit, wherein the tenon and mortise are respectively set in different edge areas of the unit; the tenon includes trapezoidal tenon, dovetail tenon, arc tenon, multi-level stepped tenon or flexible interlocking tenon structure, and the mortise includes a corresponding limiting groove structure. The mortise and tenon joint structure uses interference fit, snap fit or limiting fit to achieve stable assembly between units.

[0016] (2) Constructing an adjustable connection structure B: In the mortise and tenon connection structure, multiple limiting positions, graded insertion areas, or adjustable insertion depth structures are set so that adjacent absorbing units can form different connection states. The connection states include shallow insertion state, intermediate insertion state, and deep insertion state; different insertion states correspond to different unit spacing, air layer thickness, or array periodic structure.

[0017] Furthermore, the tenon is provided with multiple limiting steps along the insertion direction, with the spacing between adjacent limiting steps being 0.5-5 mm; the mortise is provided with a corresponding locking structure, and by changing the insertion depth of the tenon, the spacing between adjacent absorbing units can be adjusted within the range of 0.5-10 mm. Different connection states correspond to different equivalent electrical lengths and electromagnetic propagation paths, thereby forming a candidate absorbing metasurface arrangement structure.

[0018] Furthermore, adjacent absorbing units can be joined by rotational splicing, staggered splicing, gradient splicing, or interval splicing to form different metasurface array structures; the array structures include periodic arrays, gradient arrays, quasi-periodic arrays, and coded metasurface arrays. Different arrangements correspond to different equivalent dielectric parameters and impedance matching characteristics.

[0019] (3) Constructing a tenon-and-mortise interlocking absorbing metasurface C: Based on the pre-designed results from electromagnetic simulation software, multiple absorbing units A are assembled according to a predetermined connection state, and are quickly interlocked and fixed through a tenon-and-mortise connection structure, thereby forming a reconfigurable absorbing metasurface structure. The metasurface structure includes a planar assembly structure, a curved surface assembly structure, and a large-area continuous splicing structure.

[0020] Furthermore, by adjusting the arrangement order, connection state, insertion depth, or element parameters of the absorbing units, the equivalent electromagnetic parameters and absorption response characteristics of the structure can be adjusted. The element parameters include the type of absorbing component, load concentration, porosity, density parameter, thickness parameter, and element spacing. Different assembly states correspond to different electromagnetic wave propagation paths and energy dissipation methods, thereby achieving adjustment of the absorption frequency band position, bandwidth range, and response intensity.

[0021] To further illustrate the technical solution of the present invention, preferred embodiments are given below. It should be understood that the following preferred embodiments are only for explaining the present invention and should not be construed as limiting the scope of protection of the present invention. Without departing from the concept of the present invention, those skilled in the art can adjust or replace the conductive film surface blocking positions, the thickness of the foam spacer module, the number of layers, the limiting structure form, and the configuration solution method.

[0022] As a preferred embodiment of the present invention, the tenon-and-mortise interlocking absorbing metasurface is a planar assembly structure, formed by splicing multiple rectangular or hexagonal absorbing units along the planar direction. Each absorbing unit includes a lightweight porous absorbing substrate and a tenon-and-mortise connection structure disposed at its edge. The lightweight porous absorbing substrate may be melamine foam, PMI foam, or polyurethane foam, and the absorbing substrate is internally loaded with carbon-based absorbing components, magnetic absorbing components, or composite absorbing components thereof.

[0023] Preferably, the absorbing unit uses melamine foam as a lightweight framework with a thickness of 8–15 mm and a density of 6–12 mg / cm³. A graphene / carbon nanotube composite absorbing component is loaded inside the foam framework via impregnation, spraying, or vacuum-assisted impregnation. The mass ratio of graphene to carbon nanotubes can be 1:1–5:1, and the total mass fraction of the absorbing component can be 5–20 wt%. The absorbing component forms a continuous or semi-continuous conductive network within the porous framework, causing the incident electromagnetic waves to undergo multiple reflections, scattering, and dielectric losses within the porous structure.

[0024] Each absorbing unit has at least two opposite edges with a tenon-and-mortise connection structure, the tenon-and-mortise connection structure including a tenon and a mortise that mates with the tenon. The tenon has multiple limiting steps along the insertion direction, and the mortise has a locking area corresponding to the limiting steps, so that adjacent absorbing units can form shallow insertion, intermediate insertion, and deep insertion states.

[0025] Preferably, the shallow insertion state corresponds to a spacing of 6–10 mm between adjacent absorbing units, the intermediate insertion state corresponds to a spacing of 3–6 mm between adjacent absorbing units, and the deep insertion state corresponds to a spacing of 0.5–3 mm between adjacent absorbing units. By changing the depth of the tenon inserted into the mortise, the air gap, array period, and equivalent electrical length between adjacent absorbing units can be adjusted, thereby changing the impedance matching state and absorption peak position of the metasurface.

[0026] During assembly, multiple absorbing units are planarly spliced ​​together in a periodic array, staggered array, or gradient array. For applications requiring adjustment of the absorption peak position, the metasurface can be switched from a first absorption state to a second absorption state by changing the insertion state of a local or overall region. For example, when multiple absorbing units are in a shallow insertion state, the air gap between units is larger, and the equivalent period of the structure increases, which can be used to adjust the absorption response in lower frequency bands; when multiple absorbing units are in a deep insertion state, the spacing between units decreases, and the overall structure is more compact, which can be used to adjust the absorption response in higher frequency bands or wider frequency bands.

[0027] The advantages of this preferred solution are: it eliminates the need to replace the absorbing material itself; the spacing between adjacent units and the array period can be adjusted simply by changing the depth of the tenon and mortise joints, thus achieving adjustable absorption frequency band positions. Compared to fixed splicing absorbing structures, this solution offers better reconfigurability, repeatable assembly and disassembly, and frequency band adaptability, making it suitable for planar electromagnetic shielding panels, radar testing absorbing panels, detachable electromagnetic shielding structures, and multi-band absorption performance verification scenarios.

[0028] As another preferred embodiment of the present invention, the mortise and tenon interlocking absorbing metasurface is a curved surface assembly structure, formed by splicing together heterogeneous absorbing units with different geometric shapes and different absorbing parameters. The heterogeneous absorbing units include at least two of the following: flat plate absorbing units, pyramid absorbing units, deep well absorbing units, and cone absorbing units. Different absorbing units are spliced ​​together by mutually matching mortise and tenon connection structures to form a curved absorbing metasurface with gradient electromagnetic response.

[0029] Preferably, the planar absorbing unit is made of graphene or a graphene / carbon nanotube composite system loaded with melamine foam; the pyramidal absorbing unit is made of MXene loaded with PMI foam; the deep-well absorbing unit is made of carbonyl iron particles or ferrite particles loaded with polyurethane foam; and the cone-shaped absorbing unit is made of carbon-based materials and magnetic particles loaded with lightweight foam. Different absorbing units respectively provide dielectric loss, magnetic loss, multiple reflection loss, and geometrically graded impedance matching.

[0030] In the curved surface assembly structure, the absorbing units preferably adopt hexagonal, trapezoidal, or curved-edge polygonal contours to adapt to mounting surfaces with varying curvature. Adjacent absorbing units are connected by arc-shaped tenon and mortise structures or flexible interlocking tenon and mortise structures with angle compensation functions. These tenon and mortise structures allow for 1°–10° angle compensation between adjacent units, enabling multiple absorbing units to be continuously assembled to form a curved surface structure. Preferably, the radius of curvature of the curved surface assembly structure is 200–1000 mm.

[0031] In one specific configuration, the curved absorbing metasurface features gradient-arranged regions along the main propagation direction of the incident electromagnetic wave or along the span of the surface. Pyramid-shaped or cone-shaped absorbing units are placed near the center of the structure to reduce surface reflection and enhance impedance matching under wide-angle incidence. Planar or deep-well absorbing units are placed near the edge of the structure to enhance local multiple reflection paths and low-frequency absorption capabilities. Different heterogeneous absorbing units are alternately spliced, partitioned, or gradient-spliced ​​using tenon and mortise structures, resulting in a broadband absorbing structure whose geometry, absorbing components, and unit spacing are all controlled.

[0032] Furthermore, the configuration of the curved mortise and tenon interlocking broadband absorbing metasurface can be determined through parametric design methods. Specifically, this includes: first, establishing a parameter database of different heterogeneous absorbing units, including unit morphology, thickness, porosity, absorbing components, load concentration, mortise and tenon connection status, and reflection loss performance; then inputting the target operating frequency band, target reflection loss threshold, surface radius, allowable thickness, and installation area dimensions; next, generating candidate heterogeneous arrangement schemes through electromagnetic simulation or parametric optimization methods; finally, selecting the corresponding absorbing unit based on the candidate schemes and completing the curved surface assembly through the mortise and tenon interlocking structure.

[0033] The advantages of this preferred solution are as follows: by combining and arranging heterogeneous absorbing units, the electromagnetic loss advantages of different geometric structures and different absorbing components can be utilized simultaneously to achieve broadband and multi-band absorbing; the tenon and mortise connection structure with angle compensation function can make the absorbing metasurface adapt to complex curved surfaces, irregular skins or non-flat mounting surfaces; the detachable tenon and mortise connection method can replace only some absorbing units when there is local damage or changes in the target frequency band, thereby reducing maintenance costs and improving the reusability of the structure.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] (1) This invention discloses a mortise and tenon interlocking microwave absorbing metasurface structure with adjustable electromagnetic response. The structure combines microwave absorbing sponge units with a mortise and tenon interlocking structure, achieving lightweight and modular design while ensuring microwave absorption performance. Compared with traditional integral solidified microwave absorbing structures, this invention can complete the assembly of the structure without the need for adhesive bonding or integrated molding processes, and can realize repeated disassembly and rapid reconstruction of the microwave absorbing units.

[0036] (2) This invention enables the absorbing units to form different arrangement relationships, spacing structures, and periodic distributions by setting a tenon-and-mortise interlocking structure with multiple connection states. Different connection states correspond to different equivalent electromagnetic parameters and electromagnetic propagation paths, thereby achieving adjustment of the absorbing frequency band and response characteristics. Compared with traditional fixed absorbing metasurfaces, this invention can achieve switching and control of the structural electromagnetic response by changing the assembly state.

[0037] (3) The present invention introduces multi-level insertion positions and limiting structures through mortise and tenon structure, so that an adjustable air layer and spatial spacing structure are formed between adjacent absorbing units, which helps to change the reflection, scattering and dissipation process of electromagnetic waves inside the structure, thereby improving the impedance matching characteristics of the structure and broadening the effective absorbing frequency band.

[0038] (4) This invention uses modular absorbing units for assembly. Different absorbing units can use different absorbing components, density parameters, thickness parameters, or arrangement methods to form a gradient electromagnetic response structure. This structure helps to realize multi-band absorbing and broadband absorbing designs, and can quickly adjust the structural configuration according to the target application requirements.

[0039] (5) The tenon-and-mortise interlocking structure of the present invention can form planar assembly structures, curved surface assembly structures, and large-area continuous splicing structures, which helps to improve the adaptability of the wave-absorbing structure in complex curved surface skins, electromagnetic stealth structures, and irregular surfaces. Compared with traditional rigid metasurface structures, the present invention has better scalability in engineering applications on complex structural surfaces.

[0040] (6) The present invention enables the rapid replacement of locally damaged units through a detachable modular structure design, and allows the absorption structure to be reconfigured according to different usage scenarios, thereby reducing the overall maintenance cost and improving the structural reuse capability.

[0041] (7) The microwave absorbing sponge unit used in this invention can form multiple reflection and scattering paths by utilizing the porous lightweight skeleton structure, and at the same time, combined with the dielectric loss and magnetic loss of the microwave absorbing component, realize the dissipation of electromagnetic wave energy. Its lightweight porous structure can also reduce the overall structural density, which helps to meet the application requirements of lightweight microwave absorbing structures. Attached Figure Description

[0042] Figure 1This is a schematic diagram of the overall configuration and technical route of the tenon-and-mortise interlocking reconfigurable microwave absorbing metasurface of the present invention.

[0043] Figure 2 This is a schematic diagram of the parametric configuration design method and configuration generation process of the present invention.

[0044] Figure 3 This is a graph showing the electromagnetic wave reflection loss curves corresponding to different assembly states of the present invention. Embodiments of the present invention

[0045] The following describes embodiments of the method of the present invention:

[0046] Example 1

[0047] The method for preparing a flat, tenon-and-mortise interlocking microwave absorbing metasurface according to this embodiment includes the following steps:

[0048] (1) Select melamine foam with a thickness of 10 mm and a density of 8 mg / cm³ as a lightweight skeleton material and cut it into rectangular absorbing units with a side length of 50 mm.

[0049] (2) A graphene / carbon nanotube composite absorbing slurry was prepared, wherein the mass ratio of graphene to carbon nanotube was 3:1 and the total mass fraction of the absorbing component was 15 wt%. The absorbing component was then loaded into the interior of melamine foam by impregnation and dried at 60 ℃ for 12 h to obtain a flat plate absorbing unit A.

[0050] (3) A dovetail tenon structure is formed around the edges of the wave-absorbing unit A, wherein the tenon width is 5 mm and the insertion depth is 8 mm; a limiting and locking structure is set inside the mortise.

[0051] (4) Assemble multiple flat plate absorbing units A in a periodic array to form a tenon-and-mortise interlocking absorbing metasurface structure.

[0052] (5) The reflection loss performance of the structure in the range of 2-18 GHz was tested by the bow method. The results showed that the structure formed obvious absorption peaks in multiple frequency bands.

[0053] Example 2

[0054] The method for preparing a pyramid-shaped tenon-and-mortise interlocking microwave absorbing metasurface according to this embodiment includes the following steps:

[0055] (1) PMI foam was selected as a lightweight skeleton material and processed into a pyramid-shaped wave-absorbing unit with a bottom side length of 40 mm and a height of 20 mm.

[0056] (2) The pyramid-shaped foam unit was vacuum impregnated with MXene slurry, wherein the mass fraction of MXene was 10 wt%.

[0057] (3) A trapezoidal tenon and mortise structure is formed at the bottom edge of the pyramid-shaped absorbing unit.

[0058] (4) Multiple pyramid-shaped absorbing units are periodically assembled through mortise and tenon structure to form an array-type metasurface structure.

[0059] (5) The reflection loss performance of the structure in the range of 2-40 GHz was tested by the bow method. The results showed that the pyramid structure can reduce electromagnetic wave reflection and broaden the effective absorption frequency band.

[0060] Figure 1 This is a schematic diagram of the pyramid-shaped absorbing unit structure in this embodiment.

[0061] Example 3

[0062] The method for preparing a deep-well type tenon-and-mortise interlocking absorbing metasurface according to this embodiment includes the following steps:

[0063] (1) A 15 mm thick polyurethane foam is selected as a lightweight skeleton material and an array deep trap structure is formed on its surface; wherein the diameter of a single deep trap is 10 mm and the depth is 8 mm.

[0064] (2) The deep-well foam unit is impregnated with carbonyl iron particle slurry, wherein the mass fraction of carbonyl iron particles is 40 wt%.

[0065] (3) A multi-level stepped tenon structure is formed at the edge of the wave-absorbing unit.

[0066] (4) Multiple deep-well absorbing units are assembled by mortise and tenon structure to form a periodic deep-well metasurface structure.

[0067] (5) The bow-shaped method was used to test its reflection loss performance. The results showed that the deep well structure can increase the multiple reflection paths of electromagnetic waves inside the structure and improve the low-frequency absorption capability.

[0068] Example 4

[0069] The method for preparing a cone-shaped tenon-and-mortise interlocking microwave absorbing metasurface according to this embodiment includes the following steps:

[0070] (1) A cone-shaped microwave absorbing unit is formed by processing melamine foam, wherein the bottom diameter of the cone is 30 mm and the height is 25 mm.

[0071] (2) The cone-shaped foam unit is sprayed with graphene / carbonyl iron composite slurry, wherein the mass ratio of graphene to carbonyl iron is 1:2.

[0072] (3) An arc-shaped tenon structure is formed at the edge of the cone-shaped absorbing unit.

[0073] (4) Multiple cone-shaped absorbing units are assembled through mortise and tenon joints to form a curved absorbing metasurface structure.

[0074] (5) The reflection loss performance of the structure under different incident angles was tested by the bow method. The results showed that the cone-shaped structure still has stable absorption performance under wide-angle incident conditions.

[0075] Example 5

[0076] The method for preparing a heterogeneous absorbing unit assembled metasurface according to this embodiment includes the following steps:

[0077] (1) Prepare flat plate type absorbing unit, pyramid type absorbing unit and deep well type absorbing unit respectively.

[0078] (2) Among them, the flat plate unit adopts the graphene absorbing system, the pyramid type unit adopts the MXene absorbing system, and the deep trap type unit adopts the carbonyl iron absorbing system.

[0079] (3) The arrangement of different absorbing units is optimized by electromagnetic simulation software to obtain broadband absorbing performance within the target frequency band.

[0080] (4) Based on the simulation results, different structural units are alternately assembled using mortise and tenon joints to form a heterogeneous array absorbing metasurface.

[0081] (5) The reflection loss performance of the structure was tested by the bow method. The results showed that the heterogeneous unit arrangement structure has a wider effective absorption bandwidth than the single structure.

[0082] Example 6

[0083] The method for preparing an adjustable interlocking mortise and tenon absorbing metasurface according to this embodiment includes the following steps:

[0084] (1) A rectangular absorbing unit was prepared by loading graphene absorbing components onto melamine foam.

[0085] (2) A three-level limiting step structure is set in the tenon along the insertion direction, wherein the first insertion state corresponds to a 1 mm unit spacing, the second insertion state corresponds to a 4 mm unit spacing, and the third insertion state corresponds to an 8 mm unit spacing.

[0086] (3) By changing the insertion depth of the tenon, different connection states are formed and different air layer structures are constructed.

[0087] (4) The reflection loss performance under different insertion states was tested by the bow method. The results showed that the position of the absorption peak shifted as the unit spacing changed.

[0088] Example 7

[0089] The method for preparing a curved, assembled, tenon-and-mortise interlocking microwave absorbing metasurface according to this embodiment includes the following steps:

[0090] (1) Hexagonal microwave absorbing units were prepared using PMI foam, and microwave absorbing components were loaded using an MXene / graphene composite system.

[0091] (2) An arc-shaped tenon structure with angle compensation function is set on the edge of the hexagonal absorbing unit, and a 5° tilt angle is formed between adjacent splicing edges.

[0092] (3) Multiple hexagonal absorbing units are assembled in sequence through mortise and tenon structure to form a curved absorbing structure with a curvature radius of 300 mm.

[0093] (4) The reflection loss performance of the curved surface structure under different bending states was tested by the bow method. The results showed that the structure still maintained stable wave absorption performance after the curved surface was assembled.

[0094] Example 8

[0095] This embodiment presents a simulation-optimized method for configuring a heterogeneous tenon-and-mortise interlocking absorbing metasurface, comprising the following steps:

[0096] (1) Establish a microwave absorbing unit database, which includes flat plate units, pyramid units, deep well units and cone units, and record the thickness parameters, porosity parameters, microwave absorbing components and reflection loss characteristics of different units.

[0097] (2) Input the target absorption frequency band, target reflection loss value and thickness limit parameters.

[0098] (3) The CST electromagnetic simulation software was used to optimize the arrangement, assembly and tenon connection of different absorbing units and output candidate metasurface configuration schemes.

[0099] (4) Select the corresponding absorbing unit according to the simulation results, and complete the assembly of the target metasurface structure through mortise and tenon structure.

[0100] (5) The reflection loss performance of the assembled structure was tested using the bow method. The results showed that the test results and the simulation results had the same trend.

[0101] Figure 2 This is a schematic diagram of the simulation-optimized heterogeneous absorbing metasurface configuration process in this embodiment. Examples of the effects of the present invention

[0102] This example demonstrates the electromagnetic wave absorption performance of the tenon-and-mortise interlocking heterogeneous absorbing metasurface of the present invention using the bow-shaped method, comprising the following steps:

[0103] (1) Prepare planar absorbing units, pyramidal absorbing units and deep-well absorbing units respectively. The planar absorbing unit adopts a graphene-supported melamine foam system, the pyramidal absorbing unit adopts an MXene-supported PMI foam system, and the deep-well absorbing unit adopts a carbonyl iron particle-supported polyurethane foam system.

[0104] (2) A heterogeneous absorbing metasurface model was established using CST electromagnetic simulation software. The target absorbing frequency band, structural thickness limit and target reflection loss parameters were input. The different absorbing unit arrangement, tenon and mortise insertion state and unit spacing were optimized and calculated to obtain candidate absorbing configuration schemes.

[0105] (3) Based on the optimization results, different absorbing units are assembled using a mortise and tenon structure to form a heterogeneous mortise and tenon interlocking absorbing metasurface structure. Among them, different absorbing units are connected by different insertion depths to form various connection states, so as to construct different air layer spacing and periodic arrangement relationships.

[0106] (4) The reflection loss of the prepared sample was tested using the bow-shaped test system. The test frequency range was 2-40 GHz. During the test, the sample was fixed on the surface of the metal back plate and the reflection loss curves under different frequency conditions were recorded.

[0107] (5) By comparing the test results under different plugging states and different heterogeneous arrangements, it was found that changes in the tenon and mortise connection state can cause changes in the position of the absorption peak; the combination and arrangement of different geometric absorbing units can further broaden the effective absorption frequency band. Compared with a single flat plate absorbing structure, the heterogeneous tenon and mortise interlocking structure shows a more obvious absorption response in terms of broadband absorption and multi-band absorption.

[0108] Figure 3 This is a schematic diagram of the reflection loss curves corresponding to different insertion states.

[0109] Finally, it should be noted that the above embodiments are only used to explain the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Those skilled in the art can adjust or replace the shape, absorbing components, tenon and mortise connection structure, arrangement, and assembly state of the absorbing unit without departing from the technical concept of the present invention, and all such adjustments should fall within the scope of protection of the present invention.

Claims

1. A reconfigurable electromagnetically responsive mortise-and-tenon interlocking metasurface structure, characterized in that: It includes multiple absorbing units and a tenon-and-mortise connection structure set at the edge of the absorbing units; The absorbing unit is made of a lightweight porous absorbing material, which is loaded with absorbing components to dissipate electromagnetic wave energy. The mortise and tenon connection structure includes a tenon and a mortise set in the edge area of ​​the wave-absorbing unit. The tenon and the mortise are connected by a plug-in fit, a snap-fit ​​fit, or a limiting fit to realize the assembly connection between multiple wave-absorbing units. The mortise and tenon connection structure has multiple connection states, and different connection states correspond to different insertion depths, unit spacings or array period parameters to form different microwave absorbing metasurface arrangement structures. By changing the connection state, arrangement, or assembly structure between absorbing units, the equivalent electromagnetic parameters and absorption response characteristics of the absorbing metasurface can be adjusted.

2. The adjustable electromagnetic response tenon-and-mortise interlocking reconfigurable absorbing metasurface structure according to claim 1, characterized in that: The lightweight porous microwave absorbing material includes one or more of melamine foam, PMI foam, polyurethane foam, honeycomb porous materials, or aerogel porous framework materials.

3. The adjustable electromagnetic response tenon-and-mortise interlocking reconfigurable absorbing metasurface structure according to claim 1, characterized in that: The absorbing components include one or more of graphene, carbon nanotubes, reduced graphene oxide, carbon black, MXene, ferrite particles, carbonyl iron particles, nickel-based particles, or conductive polymers.

4. The adjustable electromagnetic response tenon-and-mortise interlocking reconfigurable absorbing metasurface structure according to claim 1, characterized in that: The absorbing unit is one or more of the following structures: flat plate, pyramid, deep well, cone, trapezoid, or arc surface.

5. The adjustable electromagnetic response tenon-and-mortise interlocking reconfigurable absorbing metasurface structure according to claim 1, characterized in that: The mortise and tenon joint structure includes one or more of the following: trapezoidal tenon, dovetail tenon, arc tenon, multi-level stepped tenon, or flexible interlocking tenon structure. The mortise groove is provided with a limiting groove structure or a locking structure.

6. The adjustable electromagnetic response tenon-and-mortise interlocking reconfigurable absorbing metasurface structure according to claim 1, characterized in that: The connection states include shallow insertion state, intermediate insertion state, and deep insertion state; By changing the depth of the tenon inserted into the mortise, the spacing between adjacent absorbing units can be adjusted within the range of 0.5-10 mm.

7. The adjustable electromagnetic response tenon-and-mortise interlocking reconfigurable absorbing metasurface structure according to claim 1, characterized in that: Adjacent absorbing units are arranged in a periodic, gradient, staggered, quasi-periodic, or coded manner to form a absorbing metasurface array structure.

8. The adjustable electromagnetic response tenon-and-mortise interlocking reconfigurable absorbing metasurface structure according to claim 1, characterized in that: The microwave absorbing metasurface structure can be a planar assembly structure, a curved surface assembly structure, or a large-area continuous assembly structure. The radius of curvature corresponding to the curved surface assembly structure is 50-1000 mm.

9. A method for configuring a reconfigurable absorbing metasurface based on a tenon-and-mortise interlocking structure, characterized in that, Includes the following steps: (1) Establish a parameter database for absorbing units, which includes the morphology parameters, thickness parameters, porosity parameters, absorbing component parameters and corresponding electromagnetic response parameters of the absorbing units; (2) Input the target absorption frequency band, target reflection loss value, thickness constraint conditions or surface adaptation parameters; (3) The arrangement of the absorbing units, the tenon and mortise connection status, the insertion depth and the array period parameters are optimized by using electromagnetic simulation calculation, parameter optimization calculation or data-driven configuration method; (4) Output candidate absorbing metasurface configuration schemes and complete the tenon and mortise interlocking assembly according to the predetermined connection state to form the target absorbing metasurface structure.

10. The configuration method of the reconfigurable absorbing metasurface based on the tenon-and-mortise interlocking structure according to claim 9, characterized in that: The electromagnetic simulation calculations include finite element simulation methods, finite difference time-domain methods, or electromagnetic field simulation methods based on CST or HFSS. The data-driven configuration method includes genetic algorithm optimization method, parameter mapping method or machine learning prediction method.

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