Wave-absorbing material with three-dimensional structure
By carving into a three-dimensional structure absorption layer and combining with the reflective layer, the problem of poor absorption effect of existing absorbing materials within a wide frequency bandwidth is solved, and the effective absorption of vertical and oblique incident electromagnetic waves is achieved, which improves the radar stealth effect and reduces costs.
Patent Information
- Application Number
- CN202422309393.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-23
- Publication Date
- 2025-07-01
- Estimated Expiration
- 2034-09-23
AI Technical Summary
The absorption effects of existing absorbing materials in different frequency ranges vary, making it difficult to achieve ideal absorption effects within a wide frequency bandwidth, and the layered structure cannot provide comprehensive and effective protection against the threat of oblique incident electromagnetic detection.
The absorption layer of a three-dimensional structure is carved by an engraving machine, including polyprisms, polypyramids, polyprisms, cones, round tables, and irregular curved surface structures of varying heights. The height of the three-dimensional structure perpendicular to the direction of the reflective layer is 5 to 20mm, increasing the reflection and scattering paths of electromagnetic waves and improving the absorption effect.
Materials that have good wave absorption effects in both the vertical incident direction and different oblique incident directions are achieved. In the radar stealth effect in the 2-18GHz band, the average radar reflectivity is less than 1%, and when the oblique incident is 10-60°, the average radar reflectivity is less than 3%, while reducing manufacturing costs.
Smart Images
Figure CN223052383U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to an absorbing material, in particular to a three-dimensional structure absorbing material. Background Art
[0002] Absorbing materials are often used on the surfaces of various stealth platforms to absorb radar waves, which is one of the most effective ways to achieve target stealth. With the continuous development of advanced detection technologies, current various weapons and equipment, especially large-sized vehicle equipment, are facing an increasingly severe electromagnetic environment situation, and their survivability and strike capabilities are seriously threatened.
[0003] Currently, the commonly used broadband absorbing composite material is a layered flat structure, which is composed of a wave-transmitting layer, an absorbing layer and a reflecting layer. On the one hand, a multi-layer structure composite is needed to enhance the absorbing effect. On the other hand, due to the difference in the absorbing effect of the absorbing material in different frequency ranges, it is difficult for the absorbing material with a layered flat structure to achieve an ideal absorbing effect in a very wide frequency bandwidth; moreover, the absorbing material with a layered structure cannot provide effective protection in all directions against electromagnetic detection threats with oblique incidence in different directions.
[0004] There are also three-dimensional structure absorbing materials in the prior art, but they are mainly honeycomb absorbing materials or periodic metamaterial absorbing materials, with complex structures and high manufacturing costs. Summary of the Invention
[0005] The purpose of the utility model is to solve the deficiencies existing in the prior art and provide a three-dimensional structure absorbing material with good absorbing effects in both the perpendicular incidence direction and different oblique incidence directions.
[0006] The technical solution adopted by the utility model is as follows:
[0007] A three-dimensional structure absorbing material includes an absorbing layer and a reflecting layer. The absorbing layer is carved into a three-dimensional structure by a carving machine. The three-dimensional structure is composed of one or more of prisms, pyramids, frustums of pyramids, cones, frustums of cones, and irregular curved surface structures with different heights. The height of the three-dimensional structure perpendicular to the reflecting layer is 5 - 20 mm.
[0008] For the three-dimensional structure absorbing material provided by the utility model, the absorbing layer carved into a three-dimensional structure can realize multiple reflection and scattering effects on electromagnetic waves, increase the transmission path of electromagnetic waves after entering the material, effectively accelerate the attenuation process of electromagnetic energy, and the random arrangement can make the absorbing effect more uniform, not easily form obvious reflection rules, and is more likely to form deep absorption peaks in the high-frequency band. Moreover, it can not only achieve good absorbing performance in the perpendicular incidence direction, but also have a good absorbing effect on electromagnetic waves with different oblique incidence directions, and can select different three-dimensional structures according to the needs of different equipment and different environments, with strong matching performance.
[0009] As a preferred solution, the irregular curved surface structure is composed of one or more of structures such as "Ji-shaped", "concave-shaped", and "convex-shaped".
[0010] As a preferred solution, the multi-prism is a regular multi-prism, and the multi-pyramid is a regular multi-pyramid.
[0011] As a preferred solution, the three-dimensional structure is composed of N layers, N≥2. The Nth layer of the three-dimensional structure is adjacent to the reflection layer, and the topmost layer away from the reflection layer is the first layer. The first layer is one or more of a multi-prism, multi-pyramid, multi-prism table, cone, frustum of a cone, and irregular curved surface structure. The middle N - 1 layers are one or more of a multi-prism, multi-prism table, and frustum of a cone. The reflection layer is a horizontally placed layered structure. The sum of the vertical heights of the multi-layer three-dimensional structure in the direction perpendicular to the reflection layer is 5 - 20 mm.
[0012] As a preferred solution, the N-layer three-dimensional structures are stacked together with the same central axis.
[0013] As a preferred solution, the three-dimensional structure is composed of N regular multi-prisms with different heights, N≥2. The bottom side length of the Nth layer of the regular multi-prism is 10*10 mm to 50*50 mm. The side lengths of the bottom surfaces of the N regular multi-prisms decrease successively in the direction away from the reflection layer according to d N-1 =(0.25 - 0.85)d N The sum of the heights of the N regular multi-prisms in the vertical direction is 5 - 20 mm.
[0014] As a preferred solution, the three-dimensional structure is an irregular arrangement of odd-layer regular multi-prisms.
[0015] As a preferred solution, the three-dimensional structure is an irregular arrangement of even-layer regular multi-prisms.
[0016] As a preferred solution, a flat wave-absorbing middle layer is further provided between the absorption layer and the reflection layer. The height of the flat wave-absorbing middle layer is 8 - 10 mm. The flat wave-absorbing middle layer added between the absorption layer and the reflection layer can effectively absorb the low-frequency electromagnetic waves not completely absorbed by the absorption layer.
[0017] As a preferred solution, the absorption layer is added with one of a polyimide foam layer, a polymethacrylimide foam layer, and a polyurethane foam layer directly foamed from an absorbent.
[0018] As a preferred solution, the three-dimensional structure is directly carved and formed by a carving machine according to the design pattern.
[0019] Compared with the prior art, the beneficial effects of the present utility model are:
[0020] (1) The three-dimensional structure absorbing material provided by the present utility model can match different three-dimensional structures according to the requirements of different places. On the one hand, the three-dimensional structure provides more paths for electromagnetic waves to enter the absorbing material, enabling multiple reflections and scattering of electromagnetic waves, effectively accelerating the attenuation process of electromagnetic energy, achieving good absorbing performance in the vertical incident direction, and also having a good absorption effect on electromagnetic waves with different oblique incident directions.
[0021] (2) For the three-dimensional structure absorbing material provided by the present utility model, in the vertical direction of the radar stealth effect in the 2 - 18 GHz frequency band, the average value of the radar reflectivity is less than 1%, and in the case of oblique incidence of 10 - 60°, the average value of the radar reflectivity is less than 3%.
[0022] (3) The three-dimensional structure absorbing material provided by the present utility model has a simpler structure and lower cost compared with the honeycomb three-dimensional structure, and has an obvious oblique incidence absorbing effect compared with the layered absorbing structure. Description of the Drawings
[0023] Figure 1 It is a schematic diagram of the three-dimensional structure absorbing material of Example 1.
[0024] Figure 2 It is a schematic diagram of the three-dimensional structure absorbing material of Example 2.
[0025] Figure 3 It is a schematic diagram of the three-dimensional structure absorbing material of Example 3.
[0026] Figure 4 It is a schematic diagram of the absorbing material of Comparative Example 1.
[0027] Figure 5 It is a test diagram of the electromagnetic wave reflectivity of Examples 1 - 3 and Comparative Example 1 at 0° vertical incidence.
[0028] Figure 6 It is a test diagram of the electromagnetic wave reflectivity of Examples 1 - 3 and Comparative Example 1 at 45° oblique incidence. Detailed Embodiments
[0029] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.
[0030] Example 1
[0031] As Figure 1As shown in the figure, the three-dimensional structure absorbing material provided in this embodiment includes a three-dimensional absorption layer and a reflection layer. The absorption layer is a three-dimensional structure with different heights formed by engraving a wave-absorbing polyurethane foam layer added with absorbents by a engraving machine. The three-dimensional structure in this embodiment is composed of multi-prisms, multi-pyramids, and cones to form a multi-layer structure. The height in the direction perpendicular to the reflection layer is randomly distributed from 5 to 20 mm, and the unit structure size is 40*40 mm.
[0032] The three-dimensional structure absorbing material of this embodiment is used for the test of electromagnetic wave reflectivity. When the electromagnetic wave is vertically incident at 0°, the wave-absorbing effects of each band are -14.44 dB in the S band, -14.89 dB in the C band, -17.58 dB in the X band, -17.29 dB in the Ku band, and -18.60 dB in the S-Ku band; when the electromagnetic wave is obliquely incident at 45°, the wave-absorbing effects of each band are -14.93 dB in the S band, -18.60 dB in the C band, -22.74 dB in the X band, -26.15 dB in the Ku band, and -22.00 dB in the S-Ku band.
[0033] Example 2
[0034] As Figure 2 shown in the figure, the three-dimensional structure absorbing material provided in this embodiment includes an absorption layer and a reflection layer. The absorption layer is a wave-absorbing polyurethane foam layer added with absorbents and engraved into a three-dimensional structure by a engraving machine. The three-dimensional structure in this embodiment is composed of irregularly stacked multi-layer quadrangular prisms with different heights, and the height in the direction perpendicular to the reflection layer ranges from 5 to 20 mm. The reflection layer is a 0.5 mm carbon fiber bottom plate.
[0035] The three-dimensional structure absorbing material of this embodiment is used for the test of electromagnetic wave reflectivity. When the electromagnetic wave is vertically incident at 0°, the wave-absorbing effects of each band are -8.07 dB in the S band, -14.39 dB in the C band, -28.68 dB in the X band, -24.05 dB in the Ku band, and -18.7975 dB in the S-Ku band; when the electromagnetic wave is obliquely incident at 45°, the wave-absorbing effects of each band are -12.22 dB in the S band, -11.28 dB in the C band, -24.67 dB in the X band, -30.67 dB in the Ku band, and -19.71 dB in the S-Ku band.
[0036] Example 3
[0037] As Figure 3As shown in the figure, the three-dimensional wave-absorbing material provided in this embodiment includes an absorption layer and a reflection layer. The absorption layer is an absorbing polyurethane foam layer formed by adding an absorbent and foaming, and is carved into a three-dimensional structure by a carving machine. The three-dimensional structure in this embodiment is a curved surface structure with different heights. The height of the three-dimensional structure in the direction perpendicular to the reflection layer is randomly distributed from 5 to 20 mm, and the unit structure size is from 10 to 50 mm; the reflection layer is a 0.5 mm carbon fiber bottom plate.
[0038] The three-dimensional structure wave-absorbing material of this embodiment is used for the test of electromagnetic wave reflectivity. When the electromagnetic wave is incident vertically at 0°, the wave-absorbing effects of each band are -14.62 dB in the S band, -18.28 dB in the C band, -18.28 dB in the X band, -27.20 dB in the Ku band, and -21.8675 dB in the S-Ku band; when the electromagnetic wave is incident obliquely at 45°, the wave-absorbing effects of each band are -11.46 dB in the S band, -14.14 dB in the C band, -27.29 dB in the X band, -32.82 dB in the Ku band, and -21.4275 dB in the S-Ku band.
[0039] Comparative Example 1
[0040] The difference from Example 1 is that the absorption layer is not carved into a three-dimensional structure. The wave-absorbing material is composed of an absorption layer and a reflection layer with a flat laminar structure.
[0041] The wave-absorbing material is used for the test of electromagnetic wave reflectivity. When the electromagnetic wave is incident vertically at 0°, the wave-absorbing effects of each band are -10.44 dB in the S band, -9.83 dB in the C band, -10.38 dB in the X band, -11.19 dB in the Ku band, and -10.46 dB in the S-Ku band; when the electromagnetic wave is incident obliquely at 45°, the wave-absorbing effects of each band are -7.47 dB in the S band, -7.34 dB in the C band, -7.39 dB in the X band, -7.91 dB in the Ku band, and -7.52 dB in the S-Ku band.
[0042] The test data of the wave-absorbing performance of Example 1, Example 2, Example 3, Example 4, and Comparative Example 1 at the incident angles of 0° and 45° are shown in the following table; Figure 5 、 Figure 6 The distribution is the test diagrams of the electromagnetic wave reflectivity of Examples 1-3 and Comparative Example 1 at 0° vertical incidence and 45° oblique incidence.
[0043] Table 1 Radar Reflectivity Test Data (Unit: dB)
[0044]
Claims
1. A three-dimensional structured absorbing material, comprising an absorbing layer and a reflecting layer, characterized in that: The absorption layer is carved into a three-dimensional structure, which is composed of one or more of polygonal columns, polygonal pyramids, polygonal frustums, cones, truncated cones, and irregular curved surface structures of different heights. The height of the three-dimensional structure perpendicular to the direction of the reflection layer is 5 to 20 mm.
2. A three-dimensional structured absorbing material according to claim 1, characterized in that: The irregular curved surface structure is composed of one or more structures of "J-shaped", "concave-shaped" and "convex-shaped".
3. The three-dimensional structure absorbing material according to claim 1, characterized in that: The polygonal prism is a regular polygonal prism, and the polygonal pyramid is a regular polygonal pyramid.
4. The three-dimensional structure absorbing material according to claim 1, characterized in that: The three-dimensional structure is composed of N layers of structures, N≥2. The Nth layer is adjacent to the reflective layer, and the top layer farthest from the reflective layer is the first layer. The first layer is one or more of a polygonal prism, a polygonal pyramid, a polygonal frustum, a cone, a truncated cone, and an irregular curved surface structure. The middle N-1 layers are one or more of a polygonal prism, a polygonal frustum, and a truncated cone. The sum of the vertical heights of the multiple layers of the three-dimensional structure along the direction perpendicular to the reflective layer is 5~20mm.
5. The three-dimensional structure absorbing material according to claim 4, characterized in that: The N layers of three-dimensional structures are stacked together with a central axis.
6. The three-dimensional structure absorbing material according to claim 3, characterized in that: The three-dimensional structure is composed of N layers of regular polygonal prisms of different heights, N≥2, the length of the bottom surface of the Nth layer of the regular polygonal prism is 10*10mm~50*50mm, and the length of the bottom surface of the N layers of regular polygonal prisms in the direction away from the reflective layer is d N-1 =(0.25~0.85)d N Descending successively, the sum of the heights of N layers of regular polygonal prisms along the vertical direction is 5~20mm.
7. The three-dimensional structure absorbing material according to claim 6, characterized in that: The regular polygonal prism is a regular N-prism, where N≤10.
8. The three-dimensional structured absorbing material according to claim 1, characterized in that: A flat plate absorbing middle layer is also provided between the absorbing layer and the reflecting layer, and the height of the flat plate absorbing middle layer is 8-10 mm.
9. The three-dimensional structure absorbing material according to claim 1, characterized in that: The absorption layer is one of a polyimide foam layer, a polymethacrylimide foam layer and a polyurethane foam layer which are foamed and molded with an absorbent added thereto.
10. The three-dimensional structure absorbing material according to claim 1, characterized in that: The three-dimensional structure is directly carved by an engraving machine.