Multidimensional absorption optimization all-frequency band wave-absorbing material

Abstract

The application discloses a kind of multi-dimensional absorption optimization full-band wave-absorbing material, multiple electromagnetic loss three-dimensional superstructures, light interlayer, resistance loading frequency selective surface and metal backboard are integrated in turn along Z-axis direction, the electromagnetic loss structure includes inverted and positive tower unit, surface loading resistance film;Frequency selective surface is composed of specific form metal pattern and lumped resistance, nested between each structure layer.The material has the characteristics of thin structure thickness and low area density, realizes the super wide band absorption in 1-40GHz frequency band, the maximum oblique incidence angle reaches 75 ° and still maintains excellent absorption performance.This scheme considers low-frequency absorption, structure light weight and oblique incidence stability, and is suitable for stealth materials, electromagnetic compatibility and complex electromagnetic environment protection and other fields.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic wave absorption technology, specifically to a multi-dimensional absorption optimized full-frequency wave absorbing material. Background Technology

[0002] As a functional material capable of absorbing electromagnetic wave energy and converting it into heat energy within a specific frequency band, microwave absorbing materials have broad application prospects in technologies such as radar stealth, electromagnetic compatibility, and electromagnetic interference suppression. Among these, absorption efficiency, operating bandwidth, and material thickness are key indicators for evaluating the performance of microwave absorbing materials.

[0003] In existing technologies, common structural absorbing materials often employ circuit-simulated resonant structures or lossy frequency selective surfaces (FSS) to absorb electromagnetic energy. For example, combining quarter-wavelength resonant units with multi-frequency resonant structures can achieve high absorption efficiency in specific frequency bands. However, to achieve effective absorption in the low-frequency range (e.g., 1–2 GHz), traditional quarter-wavelength principle designs typically require significant material thickness, resulting in a bulky overall structure that is unfavorable for miniaturization and engineering integration. Furthermore, since most structural designs are optimized under perpendicular electromagnetic wave incidence conditions, their absorption performance significantly decreases under oblique incidence at large angles (e.g., >60°), exhibiting insufficient stability and limiting their practical application under complex incidence conditions.

[0004] To meet the research and development needs for lightweight, broadband, thin-layered, and oblique-incidence-stable absorbing materials, researchers have attempted to optimize performance by introducing three-dimensional microstructures, resistive-loaded surfaces, and multilayer heterogeneous media. For example, some literature proposes using spiral or pyramidal dielectric stacked structures to improve the absorption bandwidth, while other technical solutions introduce lumped resistance to modulate FSS resonance characteristics to extend the absorption frequency band. However, these solutions generally have the following shortcomings: (1) complex structure, making it difficult to process and shape; (2) relatively high surface density, which is not conducive to lightweighting; (3) limited ability to coordinate high and low frequencies, making it difficult to maintain good absorption rate and angular stability simultaneously in an ultra-wide frequency range.

[0005] In view of this, the present invention proposes a multi-dimensional absorption optimized full-band absorbing material. Summary of the Invention

[0006] The purpose of this invention is to provide a multi-dimensional absorption-optimized full-band absorbing material that solves the problem that existing absorbing materials cannot simultaneously achieve thin-layer structure, lightweight characteristics, and stable absorption performance at large angles of oblique incidence across the entire frequency range.

[0007] In a first aspect, the present invention provides a multi-dimensional absorption-optimized full-band absorbing material, which, in a three-dimensional coordinate space, has the Z-axis pointing upwards as the positive direction, and comprises, from top to bottom, the following:

[0008] The structure comprises a first electromagnetic loss three-dimensional superstructure, a first lightweight interlayer, a second electromagnetic loss three-dimensional superstructure, a second lightweight interlayer, a first resistor-loaded frequency selective surface, a third lightweight interlayer, a third electromagnetic loss three-dimensional superstructure, a second resistor-loaded frequency selective surface, a fourth lightweight interlayer, a fourth electromagnetic loss three-dimensional superstructure, and a metal backplate.

[0009] Among them, the first electromagnetic loss three-dimensional superstructure and the second electromagnetic loss three-dimensional superstructure are inverted hollow or solid tower structures, and their protruding parts are completely embedded and fitted with the corresponding lightweight sandwich structure.

[0010] The third and fourth electromagnetic loss three-dimensional superstructures are hollow or solid tower structures, and their protruding parts are also fully embedded and bonded to the corresponding lightweight interlayers.

[0011] The outer surface of the tower structure is covered with a resistive film to form a multilayer resistive film structure.

[0012] As a preferred technical solution of the present invention, the first electromagnetic loss three-dimensional superstructure and the second electromagnetic loss three-dimensional superstructure are inverted tower-type unit bodies stacked layer by layer along the Z-axis direction.

[0013] Each layer of the inverted tower-type unit is a symmetrical columnar component. The unit is a structure that gradually decreases in size along the negative direction. The thickness of the first layer is 0.1 mm to 0.5 mm, and the thickness of each subsequent layer is 0.1 mm to 3.0 mm.

[0014] As a preferred embodiment of the present invention, the third electromagnetic loss three-dimensional superstructure and the fourth electromagnetic loss three-dimensional superstructure are hollow or solid tower-like components stacked upright along the Z-axis. Each layer is a symmetrical columnar structure. From top to bottom, the thickness of each layer is 0.1 mm to 3.0 mm. The tower body protrudes gradually in the negative direction and is covered with a resistive film on its outer surface.

[0015] As a preferred embodiment of the present invention, the first lightweight interlayer and the first electromagnetic loss three-dimensional superstructure are in a yin-yang mold structure relationship, and the thickness of the first lightweight interlayer is 1.0 mm to 3.0 mm.

[0016] As a preferred embodiment of the present invention, the first resistor loading frequency selection surface is mainly composed of metal structural units and a substrate. The metal structural units are composed of 3×3 metal cross rings connected to each other. A lumped resistor R1 is loaded on each arm of a single cross ring, and a lumped resistor R2 is loaded on each corner of the central ring. The substrate material can be a common board material used in PCB board manufacturing.

[0017] In a preferred embodiment of the present invention, the second resistor loading frequency selection surface is composed of a metal structural unit and a substrate, wherein the metal structural unit is a 3×3 metal square ring.

[0018] The central square ring is connected to the four square rings adjacent to it in the X and Y directions, while the four corner square rings are not connected to other square rings. Four lumped resistors R3 are symmetrically loaded on the square rings, and four lumped resistors R4 are symmetrically loaded on the four square rings connected to the central square ring.

[0019] As a preferred embodiment of the present invention, the materials of the first lightweight interlayer, the second lightweight interlayer, the third lightweight interlayer, and the fourth lightweight interlayer include, but are not limited to, a lightweight material with a low dielectric constant selected from PMI foam, PI foam, and honeycomb panels.

[0020] As a preferred technical solution of the present invention, the resistive film disposed on the three-dimensional structure of the tower electromagnetic loss can be loaded from the first or second surface in the negative direction. The number of surfaces loaded can be adjusted according to performance requirements. The resistive films together constitute the first resistive film structure, the second resistive film structure, the third resistive film structure and the fourth resistive film structure.

[0021] As a preferred embodiment of the present invention, the metal backing plate is made of one of gold, silver and copper metals, and can be prepared by inkjet printing, magnetron sputtering or bonding and attached to its respective substrate.

[0022] As a preferred embodiment of the present invention, the total thickness of the entire structure along the Z-axis is less than one-eighth of the wavelength corresponding to the starting frequency point with a reflection coefficient below -10dB, and the interface error between any two adjacent structural layers in the absorbing material is controlled within ±0.1mm; the overall structure is composed of lightweight media such as foam and hollow three-dimensional structure, and has low surface density.

[0023] The technical effects and advantages provided by the present invention in the above technical solution are as follows:

[0024] This invention achieves stable absorption capability with a reflection coefficient below -10dB in the 1–40GHz frequency band by sequentially integrating inverted and upright electromagnetic loss three-dimensional tower structures, low dielectric constant lightweight interlayers, and two different configurations of resistive-loaded frequency selective surfaces in three-dimensional coordinate space, while keeping the structural thickness within 20mm. Because the tower structure forms a gradually deforming cross-section from small to large in the Z-axis direction and loads multiple resistive films on the surface, it significantly improves interlayer impedance matching characteristics and reduces incident wave reflectivity, further enhancing the low-frequency absorption effect. Simultaneously, the frequency selective surface achieves coordinated control of high-frequency and low-frequency absorption regions by adjusting the distribution of heterogeneous lumped resistors at different positions of the metal pattern. The multi-layer nested assembly of the above structural units significantly reduces the material surface density and enhances stability at large-angle oblique incidence, achieving oblique incidence absorption capabilities of up to 70° and 75° under TE and TM polarization, respectively. The overall performance is superior to existing thick-layer or single-layer absorbing materials. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0026] Figure 1 This is a schematic diagram of the structural unit of the multi-dimensional absorption optimization full-band absorbing material of the present invention.

[0027] Figure 2 This is a schematic diagram of the first electromagnetic loss three-dimensional superstructure of the present invention and the location of the first resistive film structure covering it;

[0028] Figure 3 This is a schematic diagram of the second electromagnetic loss three-dimensional superstructure of the present invention and the location of the second resistive film structure covering it;

[0029] Figure 4 This is a schematic diagram of the location of the third electromagnetic loss three-dimensional superstructure and the third resistive film structure covering it in this invention;

[0030] Figure 5 This is a schematic diagram of the fourth electromagnetic loss three-dimensional superstructure of the present invention and the location of the fourth resistive film structure covering it.

[0031] Figure 6 This invention relates to the reflection coefficient under different oblique incidence angles in the 1-45GHz frequency band and TE polarization.

[0032] Figure 7This invention measures the absorption rate of the present invention under different oblique incidence angles in the 1-45GHz frequency band and TE polarization.

[0033] Figure 8 This invention relates to the reflection coefficient under different oblique incidence angles in the 1-45GHz frequency band and TM polarization.

[0034] Figure 9 This refers to the absorption rate of the present invention under different oblique incidence angles in the 1-45GHz frequency band and TM polarization.

[0035] The structure comprises: 1. First electromagnetic loss three-dimensional superstructure; 2. First resistive film structure; 3. First lightweight interlayer; 4. Second electromagnetic loss three-dimensional superstructure; 5. Second resistive film structure; 6. Second lightweight interlayer; 7. First resistor loading frequency selective surface; 8. Third lightweight interlayer; 9. Third resistive film structure; 10. Third electromagnetic loss three-dimensional superstructure; 11. Second resistor loading frequency selective surface; 12. Fourth lightweight interlayer; 13. Fourth resistive film structure; 14. Fourth electromagnetic loss three-dimensional superstructure; 15. Metal backplate. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings.

[0037] Throughout the accompanying drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The described embodiments are only a part of the embodiments of this application, not all of them. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0038] Example 1

[0039] Please see Figure 1-5As shown, this embodiment provides a multidimensional absorption-optimized full-band absorbing material. By integrating two layers of resistive frequency surface with resistive loading, four layers of three-dimensional structure covered with resistive films, and four lightweight interlayers, it successfully achieves excellent absorption characteristics covering the entire frequency range from 1 to 40 GHz. The overall thickness is less than one-eighth of the wavelength corresponding to the starting frequency point where the reflection coefficient is below -10 dB, demonstrating a significant advantage in thin-layer design. Experimental results show that this design can maintain stable and efficient absorption performance even under large-angle incident conditions, with a maximum oblique incident angle of up to 70°. This research achievement meets the current demand for absorbing materials with thin-layer characteristics and excellent oblique incident stability across the entire frequency range.

[0040] In a three-dimensional coordinate space, with the Z-axis pointing upwards as the positive direction, the structure from top to bottom includes a first electromagnetic loss three-dimensional superstructure 1, a first lightweight interlayer 3, a second electromagnetic loss three-dimensional superstructure 4, a second lightweight interlayer 6, a first resistor-loaded frequency-selective surface 7, a third lightweight interlayer 8, a third electromagnetic loss three-dimensional superstructure 10, a second resistor-loaded frequency-selective surface 11, a fourth lightweight interlayer 12, a fourth electromagnetic loss three-dimensional superstructure 14, and a metal backplate 15. The first electromagnetic loss three-dimensional superstructure 1 is an inverted hollow or solid tower structure (the bulge gradually decreases in size along the negative direction), with a resistive film covering its surface. The protruding portion of the first electromagnetic loss three-dimensional superstructure 1 is completely embedded and bonded to the first lightweight interlayer 3. The second electromagnetic loss three-dimensional superstructure 4 is also an inverted hollow or solid tower structure (the bulge gradually decreases in size along the negative direction), and a resistive film can be covered its surface. The protruding portion of the second electromagnetic loss three-dimensional superstructure 4 is completely embedded and bonded to the second lightweight interlayer 6. The third electromagnetic loss three-dimensional superstructure 10 is a hollow or solid tower structure (the bulges gradually increase in size along the negative direction), and a resistive film can be covered on its surface. The protruding part of the third electromagnetic loss three-dimensional superstructure 10 is completely embedded and bonded to the third lightweight interlayer 8. The fourth electromagnetic loss three-dimensional superstructure 14 is a hollow or solid tower structure (the bulges gradually increase in size along the negative direction), and a resistive film can be covered on its surface. The protruding part of the fourth electromagnetic loss three-dimensional superstructure 14 is completely embedded and bonded to the fourth lightweight interlayer 12.

[0041] The embodiment described uses a multidimensional absorption optimization full-band absorbing material, which is verified by electromagnetic simulation software CST2025. It employs a Floquet port and uses unit cells arranged periodically in the XOY plane to simulate an infinitely large plane, with a period of 15.0~30.0 mm.

[0042] The multidimensional absorption optimized full-band absorbing material, comprising the first electromagnetic loss three-dimensional superstructure 1, the second electromagnetic loss three-dimensional superstructure 4, the third electromagnetic loss three-dimensional superstructure 10, and the fourth electromagnetic loss three-dimensional superstructure 14, is made of materials that can be prepared by 3D printing, flatbed engraving, and molding processes, and possess certain magnetic loss or dielectric loss characteristics, such as PLA, PET, Carbon / Glass Fiber Reinforced PLA, PPA-CF / GF, glass fiber cloth, glass fiber sheets, etc., with a relative permittivity ranging from 1.5 to 5.0.

[0043] The multidimensional absorption optimized full-band absorbing material has a first electromagnetic loss three-dimensional superstructure 1, which is an inverted hollow or solid tower structure. Each layer is a symmetrical columnar structure. In the three-dimensional coordinate space, the Z-axis is upward, and the thickness of the first layer is 0.1~0.5mm from top to bottom. The thickness of each subsequent layer is 0.1~3.0mm. The number of layers of the first electromagnetic loss three-dimensional superstructure 1 can be easily adjusted according to design requirements. The resistive film is loaded starting from the second surface in the negative direction. The number of loaded surfaces can be easily adjusted according to performance requirements. All the resistive films loaded on the first electromagnetic loss three-dimensional superstructure 1 together constitute the first resistive film structure 2.

[0044] The multidimensional absorption optimized full-band absorbing material has a first lightweight interlayer 3 and a first electromagnetic loss three-dimensional superstructure 1 that are mutually yin and yang modes, and the thickness of the first lightweight interlayer 3 is 1.0-3.0mm.

[0045] The multidimensional absorption optimized full-band absorbing material has a second electromagnetic loss three-dimensional superstructure 4 that is an inverted hollow or solid tower structure. Each layer is a symmetrical columnar structure. In the three-dimensional coordinate space, the Z-axis is upward as the positive direction. From top to bottom, the thickness of each layer is 0.1~3.0mm. The number of layers of the tower structure of the second electromagnetic loss three-dimensional superstructure 4 can be easily adjusted according to design requirements. The resistive film can be loaded starting from the first surface in the negative direction. The number of loaded surfaces can be easily adjusted according to performance requirements. All the resistive films loaded on the second electromagnetic loss three-dimensional superstructure 4 together constitute the second resistive film structure 5.

[0046] The multidimensional absorption optimized full-band absorbing material has a second lightweight interlayer 6 and a second electromagnetic loss three-dimensional superstructure 4 that are mutually yin-yang mode structures, and the thickness of the first lightweight interlayer 3 is 1.0-5.0 mm.

[0047] The aforementioned multidimensional absorption-optimized full-band absorbing material, with the first resistor loading frequency selected on surface 7, is mainly composed of metal structural units and a substrate. The metal structural units are interconnected 3x3 metal cross rings. Each arm of a single cross ring is loaded with a lumped resistor R1, with a resistance value of 50-200Ω. Each corner of the central ring is loaded with a lumped resistor R2, with a resistance value of 50-400Ω. The linewidth of the metal cross rings is 0.1-1.5mm, the side length of the rings is 1.5-3.0mm, and the length of the cross arms is 0.5-3.0mm. The substrate material can be common PCB board materials, such as FR4, PI, F4B, etc.

[0048] The multidimensional absorption optimized full-band absorbing material has a third electromagnetic loss three-dimensional superstructure 10, which is an upright hollow or solid tower structure. Each layer is a symmetrical columnar structure. In the three-dimensional coordinate space, the Z-axis is upward as the positive direction. From top to bottom, the thickness of each layer is 0.1~3.0mm. The number of layers of the tower structure of the third electromagnetic loss three-dimensional superstructure 10 can be easily adjusted according to design requirements. The resistive film can be loaded starting from the first surface in the negative direction. The number of loaded surfaces can be easily adjusted according to performance requirements. All the resistive films loaded on the first electromagnetic loss three-dimensional superstructure 1 together constitute the third resistive film structure 9.

[0049] The multidimensional absorption optimized full-band absorbing material has a third lightweight interlayer 8 and a third electromagnetic loss three-dimensional superstructure 10 that are mutually yin-yang mode structures, and the thickness of the third lightweight interlayer 8 is 1.0-5.0mm.

[0050] The aforementioned multidimensional absorption-optimized full-band absorbing material, with the second resistor loading frequency selected on surface 11, is mainly composed of metal structural units and a substrate. The metal structural units are 3x3 metal square rings, where the central square ring is connected to the four adjacent square rings in the X and Y directions, while the four corner square rings are not connected to other square rings. The side length of the central square ring is 4.0-8.0 mm, and the metal wire width is 0.3-1.5 mm. Four lumped resistors R3 are symmetrically loaded on the square ring, each with a resistance value of 20-300 Ω. The four square rings connected to the central square ring also have side lengths of 4.0-8.0 mm and metal wire widths of 0.3-1.5 mm. Four lumped resistors R4 are symmetrically loaded on these square rings, each with a resistance value of 20-300 Ω. The four corner square rings have a side length of 4.0-8.0mm and a metal line width of 0.3-1.5mm. Four lumped resistors R3 are symmetrically loaded on the square rings, each with a resistance of 20-300Ω. The substrate material can be a common material used in PCB manufacturing processes, such as FR4, PI, F4B, etc.

[0051] The multidimensional absorption optimized full-band absorbing material has a fourth electromagnetic loss three-dimensional superstructure 14, which is an upright hollow or solid tower structure. Each layer is a symmetrical columnar structure. In the three-dimensional coordinate space, the Z-axis is upward as the positive direction. From top to bottom, the thickness of each layer is 0.1~3.0mm. The number of layers of the tower structure of the fourth electromagnetic loss three-dimensional superstructure 14 can be easily adjusted according to design requirements. The resistive film can be loaded starting from the first surface in the negative direction. The number of loaded surfaces can be easily adjusted according to performance requirements. All the resistive films loaded on the fourth electromagnetic loss three-dimensional superstructure 14 together constitute the fourth resistive film structure 13.

[0052] The multidimensional absorption optimized full-band absorbing material has a fourth lightweight interlayer 12 and a fourth electromagnetic loss three-dimensional superstructure 14 that are mutually yin-yang mode structures, and the thickness of the first lightweight interlayer 3 is 3.0-15.0 mm.

[0053] The multidimensional absorption optimized full-band absorbing material is made of gold, silver, or copper metal, with the metal units of the first resistance loading frequency selection surface 7 and the second resistance loading frequency selection surface 11 and the metal back plate 15 being prepared by methods such as inkjet printing, magnetron sputtering, and bonding and attached to their respective substrates.

[0054] In the multi-dimensional absorption optimization full-band absorbing material of the embodiments of the present invention, the materials of the first lightweight interlayer 3, the second lightweight interlayer 6, the third lightweight interlayer 8 and the fourth lightweight interlayer 12 can be lightweight materials with low dielectric constants such as PMI foam, PI foam, and honeycomb panels.

[0055] Figure 6 The present invention provides reflection coefficient curves for electromagnetic waves at different incident angles under TE polarization in the 1.0-45.0 GHz frequency band when the electromagnetic waves are vertically incident. When the electromagnetic waves are vertically incident, the frequency band with a reflection coefficient below -10 dB in the embodiment is 1.6-45.0 GHz, and the average reflection coefficient in the L-band is -8.5 dB. It has both ultra-wideband absorption characteristics and ideal low-frequency absorption performance.

[0056] Figure 7 This is an embodiment of the present invention. In the 1.0-45.0 GHz frequency band, under TE polarization, the absorption rate curves of electromagnetic waves at different incident angles show that when the oblique incident angle is 60°, the absorption rate is between 70% and 80% in the 1.7-6.9 GHz frequency band, between 80% and 90% in the 6.9-9.0 GHz and 18.0-32.6 GHz frequency bands, and greater than 90% in the 9.0-18.0 GHz and 32.6 GHz-45.0 GHz frequency bands, exhibiting good oblique incident performance.

[0057] Figure 8The present invention provides the reflection coefficient curves of electromagnetic waves at different incident angles in the 1.0-45.0 GHz frequency band under TM polarization. When the oblique incident angle is 45°, the frequency band with a reflection coefficient below -10dB is 2.4-45.0 GHz, which is only 0.8 GHz off compared to vertical incident.

[0058] Figure 9 This is an embodiment of the present invention. In the 1.0-45.0 GHz frequency band, under TM polarization, the absorption rate curves of electromagnetic waves at different incident angles show that when the oblique incident angle is 75°, the absorption rate is between 70% and 80% in the 3.1-5.7 GHz frequency band, between 80% and 90% in the 5.7-6.3 GHz and 6.9-10.1 GHz frequency bands, and greater than 90% in the 6.3-6.9 GHz and 10.1-45.0 GHz frequency bands, exhibiting excellent oblique incident performance.

[0059] Therefore, this invention proposes a novel design method for full-band absorbing materials, achieving excellent electromagnetic loss performance through multi-dimensional absorption optimization technology. Specifically, this scheme embeds a three-dimensional electromagnetic loss superstructure into a lightweight sandwich layer, combining tower-shaped and hollow structure designs, and covers the surface of the three-dimensional electromagnetic loss superstructure with a resistive film. Simultaneously, a frequency-selective surface with strong resonant loss characteristics is applied using a resistor, ultimately achieving full-band absorption performance with a relative thickness of only 0.11λL. This effectively reduces the material's surface density, providing strong support for thin-layer design, and ensures excellent oblique incidence stability. This innovative design not only meets the current demand for lightweight and thin absorbing materials but also provides technical support for improving the performance of electronic devices and reducing the impact of electromagnetic pollution on human health and the environment.

[0060] The design principle of this embodiment is as follows:

[0061] a. The second resistor loading frequency selection surface 11 is a full-band strong absorption layer, the first resistor loading frequency selection surface 7 is a full-band strong absorption compensation layer, and the first resistor loading frequency selection surface 7 and the second resistor loading frequency selection surface 11 are the main functional layers that determine the low-frequency absorption performance.

[0062] b. The different resistance values ​​of the second resistor loading frequency selection surface 11 and the first resistor loading frequency selection surface 7, which are loaded on different parts of the annular structure, are the main reason for achieving full-band absorption.

[0063] c. The first electromagnetic loss three-dimensional superstructure 1, the first lightweight interlayer 3, the resistive film frequency selective surface 1, and the second electromagnetic loss three-dimensional superstructure 4 are the main functional layers for adjusting high-frequency absorption performance.

[0064] d. The first electromagnetic loss three-dimensional superstructure 1, the second electromagnetic loss three-dimensional superstructure 4, the third electromagnetic loss three-dimensional superstructure 10, and the fourth electromagnetic loss three-dimensional superstructure 14 can adjust the equivalent dielectric constant of each interlayer and the impedance matching characteristics of the absorbing material through tower-shaped design and hollow structure design. They are key structures for achieving broadband absorption performance adjustment, thickness reduction, and reduction of the surface density of the absorbing material.

[0065] e. The first electromagnetic loss three-dimensional superstructure 1, the second electromagnetic loss three-dimensional superstructure 4, the third electromagnetic loss three-dimensional superstructure 10 and the fourth electromagnetic loss three-dimensional superstructure 14 can improve the electromagnetic loss characteristics of different frequency bands through the resistive film covering them, and are key structures for optimizing oblique incidence performance.

[0066] f. The first electromagnetic loss three-dimensional superstructure 1 adopts an inverted pyramid design from thin to thick, which can achieve high-frequency impedance adjustment and surface impact resistance.

[0067] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A multidimensional absorption-optimized full-band absorbing material, characterized in that, In three-dimensional coordinate space, the Z-axis is upward with positive direction, and from top to bottom includes: The structure comprises a first electromagnetic loss three-dimensional superstructure (1), a first lightweight interlayer (3), a second electromagnetic loss three-dimensional superstructure (4), a second lightweight interlayer (6), a first resistor loading frequency selective surface (7), a third lightweight interlayer (8), a third electromagnetic loss three-dimensional superstructure (10), a second resistor loading frequency selective surface (11), a fourth lightweight interlayer (12), a fourth electromagnetic loss three-dimensional superstructure (14), and a metal backplate (15); the first lightweight interlayer (3) and the first electromagnetic loss three-dimensional superstructure (1) are in a male-female mold structure relationship, and the thickness of the first lightweight interlayer (3) is 1.0 mm to 3.0 mm; Among them, the first electromagnetic loss three-dimensional superstructure (1) and the second electromagnetic loss three-dimensional superstructure (4) are inverted hollow or solid tower structures, and their protruding parts are completely embedded and fitted with the corresponding lightweight sandwich structures (3, 6); the first electromagnetic loss three-dimensional superstructure (1) and the second electromagnetic loss three-dimensional superstructure (4) are inverted tower units stacked layer by layer along the Z-axis direction. Each layer of the inverted tower-type unit is a symmetrical columnar component. The unit is a structure that gradually decreases in size along the negative direction. The thickness of the first layer is 0.1 mm to 0.5 mm, and the thickness of each subsequent layer is 0.1 mm to 3.0 mm. The third electromagnetic loss three-dimensional superstructure (10) and the fourth electromagnetic loss three-dimensional superstructure (14) are hollow or solid tower structures, and their protruding parts are also completely embedded and attached to the corresponding lightweight interlayer; the third electromagnetic loss three-dimensional superstructure (10) and the fourth electromagnetic loss three-dimensional superstructure (14) are hollow or solid tower components stacked upright along the Z-axis direction, each layer is a symmetrical columnar structure, and from top to bottom, the thickness of each layer is 0.1mm to 3.0mm, the tower body protrudes gradually larger along the negative direction, and the outer surface is covered with a resistive film; The outer surface of the tower structure is covered with a resistive film to form a multilayer resistive film structure.

2. The multidimensional absorption-optimized full-band absorbing material according to claim 1, characterized in that, The first resistor loading frequency selection surface (7) is composed of a metal structure unit and a substrate. The metal structure unit is composed of 3×3 metal cross rings connected to each other. A lumped resistor R1 is loaded on each arm of a single cross ring, and a lumped resistor R2 is loaded on each corner of the central ring.

3. The multidimensional absorption-optimized full-band absorbing material according to claim 1, characterized in that, The second resistor-loaded frequency selection surface (11) is composed of a metal structural unit and a substrate, wherein the metal structural unit is a 3×3 metal square ring, The central square ring is connected to the four square rings adjacent to it in the X and Y directions, while the four corner square rings are not connected to other square rings. Four lumped resistors R3 are symmetrically loaded on the square rings, and four lumped resistors R4 are symmetrically loaded on the four square rings connected to the central square ring.

4. The multidimensional absorption-optimized full-band absorbing material according to claim 3, characterized in that, The materials of the first lightweight interlayer (3), the second lightweight interlayer (6), the third lightweight interlayer (8) and the fourth lightweight interlayer (12) include PMI foam, PI foam or honeycomb board.

5. The multidimensional absorption-optimized full-band absorbing material according to claim 4, characterized in that, The resistive film set on the three-dimensional structure of the tower electromagnetic loss is loaded from the first or second surface in the negative direction. The number of surfaces loaded is adjusted according to the performance requirements. The resistive films together constitute the first resistive film structure (2), the second resistive film structure (5), the third resistive film structure (9) and the fourth resistive film structure (13).

6. The multidimensional absorption-optimized full-band absorbing material according to claim 5, characterized in that, The metal backplate (15) is made of one of gold, silver and copper metals and is prepared by inkjet printing, magnetron sputtering or bonding and attached to its respective substrate.

7. The multidimensional absorption-optimized full-band absorbing material according to claim 1, characterized in that, The total thickness of the entire structure along the Z-axis is less than one-eighth of the wavelength corresponding to the starting frequency point where the reflection coefficient is below -10dB, and the interface error between any two adjacent structural layers in the absorbing material is controlled within ±0.1mm.

Images