Three-dimensional structure wave-absorbing metamaterial

Abstract

This invention belongs to the field of electromagnetic wave absorbing technology, specifically disclosing a three-dimensional structure absorbing metamaterial, comprising a first three-dimensional structural layer, a second three-dimensional structural layer, and a metal backplate arranged sequentially from top to bottom. The first three-dimensional structural layer includes a first top layer and a first three-dimensional absorption enhancement skeleton disposed on the lower surface of the first top layer. A first high-impedance metasurface and a second high-impedance metasurface are loaded at intervals on the lower surface of the first three-dimensional absorption enhancement skeleton. The second three-dimensional structural layer includes a second top layer and a second three-dimensional absorption enhancement skeleton disposed on the lower surface of the second top layer. A third high-impedance metasurface is loaded on the top surface of the second top layer. This invention, employing the aforementioned three-dimensional structure absorbing metamaterial, can achieve ultra-wideband absorption and large-angle stability at a relatively thin thickness, which is beneficial for the lightweight and broadband application of absorbers and has great practical value in the field of electromagnetic compatibility.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic wave absorption technology, and in particular to a three-dimensional structure wave-absorbing metamaterial. Background Technology

[0002] The rapid development and widespread application of electronic information technology have greatly facilitated people's lives, but the resulting electromagnetic pollution has also brought increasingly significant harm. Electromagnetic absorbing materials are one of the effective methods to solve this problem. In practical applications, with the continuous advancement of the engineering application of resonant absorbing structures, the requirements for their integration with the mechanical properties of structural components, conformal design of irregular curved surfaces, and flexibility in the design of finite thickness absorbing performance are gradually increasing, posing new challenges to the manufacturing methods of absorbing materials. Furthermore, traditional circuit-simulated absorbers based on resistive frequency-selective surfaces typically use air layers or lightweight foam materials as intermediate spacers, which generally lack mechanical properties and are difficult to load onto curved surfaces. The layer-by-layer accumulation of 3D printing and its insensitivity to shape complexity in terms of manufacturing costs provide a feasible solution to this problem.

[0003] The structural designability of 3D printing technology is a significant advantage in material forming. Through simple 3D printing, samples of any structure can be formed without the need for additional mold design and manufacturing. For electromagnetic wave absorbing materials, 3D structures help reduce the density of the material and allow electromagnetic waves to be reflected multiple times within the porous structure. Combining 3D absorbing structures with resistive frequency-selective surfaces to create absorbing composite materials offers a new possibility for achieving high-performance absorption. Summary of the Invention

[0004] The purpose of this invention is to provide a three-dimensional structured microwave absorbing metamaterial that can achieve ultra-wideband absorption and large-angle stability at a relatively thin thickness, which is beneficial for the lightweight and broadband application of microwave absorbers and has great practical value in the field of electromagnetic compatibility.

[0005] To achieve the above objectives, the present invention provides a three-dimensional structure absorbing metamaterial, comprising a first three-dimensional structure layer, a second three-dimensional structure layer and a metal backplate arranged sequentially from top to bottom. The first three-dimensional structure layer includes a first top layer and a first three-dimensional absorption enhancement skeleton disposed on the lower surface of the first top layer. The lower surface of the first three-dimensional absorption enhancement skeleton is loaded with a first high-impedance metasurface and a second high-impedance metasurface at intervals.

[0006] The second three-dimensional structural layer includes a second top layer and a second three-dimensional absorption-enhancing skeleton disposed on the lower surface of the second top layer, and a third high-impedance metasurface is loaded on the top surface of the second top layer.

[0007] Preferably, the first three-dimensional absorption-enhancing skeleton is a densely packed plurality of hollow, stepped, hexagonal prism-shaped structures.

[0008] Preferably, the number of coaxial hollow regular hexagonal prisms in the first three-dimensional absorption and enhancement skeleton is 3-6, wherein the smallest hollow regular hexagonal prism has a side length of 2mm-4mm and a height of 0.2mm-1.5mm, the width of the coaxial hollow regular hexagonal prism is 0.4mm-1mm, and the height gradient of the coaxial hollow regular hexagonal prism is 0.3mm-1.0mm.

[0009] Preferably, the materials of the first three-dimensional structural layer and the second three-dimensional structural layer are all one of carbon-based absorbent, polymer absorbent, and ceramic-based absorbent, and their dielectric constant is between 2.0 and 5.0.

[0010] Preferably, the first top layer, the second top layer, and the metal back plate are all regular hexagonal structures, with the side length of the first top layer and the second top layer both being 4.5mm-12.0mm and the thickness being 0.1mm-0.3mm.

[0011] Preferably, the second three-dimensional absorption enhancement framework is a single hollow regular hexagonal prism structure.

[0012] Preferably, the second three-dimensional absorption-enhancing skeleton has a side length of 2.0mm-8.0mm, a width of 0.4mm-1.5mm, and a height of 1.2mm-3.6mm.

[0013] Preferably, the first high-resistivity metasurface, the second high-resistivity metasurface, and the third high-resistivity metasurface are all made of resistive ink, with a sheet resistance of 50-300 ohm / sq.

[0014] Preferably, the first high-impedance metasurface, the second high-impedance metasurface, and the third high-impedance metasurface are all prepared on the first three-dimensional structural layer or the second three-dimensional structural layer by one of screen printing, mechanical engraving, or magnetron sputtering.

[0015] Preferably, both the first three-dimensional structural layer and the second three-dimensional structural layer are formed by fused deposition modeling.

[0016] Therefore, the present invention employs the above-mentioned three-dimensional structure absorbing metamaterial, and the beneficial effects are as follows:

[0017] (1) The three-dimensional structure absorbing metamaterial prepared by the present invention has the following characteristics: under TE polarization, when electromagnetic waves are incident perpendicularly, the frequency band with reflectivity below -10dB is 7.9GHz-40.0GHz, and the relative bandwidth is 134.0%; when the incident angle of electromagnetic waves is 45°, the frequency band with reflectivity below -10dB is 9.4GHz-40GHz, and the relative bandwidth is 123.9%; when the incident angle of electromagnetic waves is 60°, the reflectivity is below -10dB in the range of 18.8GHz-33.7GHz, and the absorption bandwidth is 14.9GHz.

[0018] (2) This invention provides multiple loading interfaces for the high-impedance metasurface through three-dimensional structural design, and prints the high-impedance metasurface on the three-dimensional structure to achieve broadband absorption performance with stable oblique incidence angle and excellent mechanical properties. That is, it can have ultra-wideband absorption and large-angle stability with a relatively thin thickness, which is conducive to the realization of functional structure integration, and is conducive to the lightweight and thin broadband application of the absorber. It has great practical value in the field of electromagnetic compatibility.

[0019] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of an embodiment of a three-dimensional structure absorbing metamaterial of the present invention;

[0021] Figure 2 This is a cross-sectional view of an embodiment of a three-dimensional structure microwave absorbing metamaterial of the present invention;

[0022] Figure 3 This is a schematic diagram of the first three-dimensional structural layer of an embodiment of a three-dimensional structure absorbing metamaterial of the present invention;

[0023] Figure 4 This is a perspective view of an embodiment of a three-dimensional structure microwave absorbing metamaterial according to the present invention;

[0024] Figure 5 This is a schematic diagram of the second three-dimensional structural layer of an embodiment of a three-dimensional structure absorbing metamaterial of the present invention;

[0025] Figure 6 This is a graph showing the variation of TE wave reflection coefficient with frequency at different incident angles according to an embodiment of a three-dimensional structure absorbing metamaterial of the present invention;

[0026] Figure 7 This is a graph showing the variation of TE wave absorption rate with frequency at different incident angles according to an embodiment of a three-dimensional structure absorbing metamaterial of the present invention;

[0027] Figure 8 This is a graph showing the variation of TM wave reflection coefficient with frequency at different incident angles according to an embodiment of a three-dimensional structure absorbing metamaterial of the present invention;

[0028] Figure 9 This is a graph showing the variation of TM wave absorption rate with frequency at different incident angles for an embodiment of a three-dimensional structure absorbing metamaterial of the present invention;

[0029] Figure 10 This is a comparison diagram of the reflectivity curves of a three-dimensional structure absorbing metamaterial of the present invention and Comparative Example 1 when electromagnetic waves are incident perpendicularly.

[0030] Figure 11 This is a diagram showing the variation of TE reflectivity with frequency at different incident angles for a three-dimensional absorbing metamaterial according to the present invention (Comparative Example 1).

[0031] Figure 12 This is a diagram showing the variation of TE reflectivity with frequency at different incident angles for a three-dimensional absorbing metamaterial according to the present invention (Comparative Example 2).

[0032] Figure 13 This is a diagram showing the variation of TE reflectivity with frequency at different incident angles for a three-dimensional absorbing metamaterial according to the present invention.

[0033] Figure Labels

[0034] 1. First three-dimensional structural layer; 2. First high-impedance metasurface; 3. Second high-impedance metasurface; 4. Third high-impedance metasurface; 5. Second three-dimensional structural layer; 6. Metal backplate; 7. First three-dimensional absorption-enhancing framework; 8. First top layer; 9. Second top layer; 10. Second three-dimensional absorption-enhancing framework. Detailed Implementation

[0035] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0036] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0037] Example 1

[0038] like Figures 1-5As shown, a three-dimensional absorbing metamaterial includes a first three-dimensional structural layer 1, a second three-dimensional structural layer 5, and a metal backplate 6 arranged sequentially from top to bottom. The first three-dimensional structural layer 1 includes a first top layer 8 and a first three-dimensional absorption-enhancing framework 7 disposed on the lower surface of the first top layer 8. The first three-dimensional absorption-enhancing framework 7 is a plurality of closely spaced hollow hexagonal prism stepped gradient structures. The lower surface of the first three-dimensional absorption-enhancing framework 7 is loaded with a first high-impedance metasurface 2 and a second high-impedance metasurface 3 at intervals. The second three-dimensional structural layer 5 includes a second top layer 9 and a second three-dimensional absorption-enhancing framework 10 disposed on the lower surface of the second top layer 9. The second three-dimensional absorption-enhancing framework 10 is a single hollow hexagonal prism structure. The top surface of the second top layer 9 is loaded with a third high-impedance metasurface 4.

[0039] In this embodiment, both the first three-dimensional structural layer 1 and the second three-dimensional structural layer 5 are made of polymer absorbent with a dielectric constant of 3.2. Both the first three-dimensional structural layer 1 and the second three-dimensional structural layer 5 are formed by fused deposition modeling. The first high-resistivity metasurface 2, the second high-resistivity metasurface 3, and the third high-resistivity metasurface 4 are made of resistive ink with a sheet resistance of 50 ohms / sq, and are prepared on the first three-dimensional structural layer 1 or the second three-dimensional structural layer 5 by screen printing. The first top layer 8, the second top layer 9, and the metal backing plate 6 are all regular hexagonal structures. The side length of the first top layer 8 and the second top layer 9 are both 4.96 mm, and the thickness is 0.2 mm. The first three-dimensional absorption enhancement skeleton 7 has four coaxial hollow regular hexagonal prisms, among which the smallest hollow regular hexagonal prism has a side length of 2.12 mm and a height of 0.5 mm, the width of the coaxial hollow regular hexagonal prism is 0.6 mm, and the height gradient of the coaxial hollow regular hexagonal prism is 0.5 mm. The second three-dimensional absorption and enhancement skeleton 10 has a side length of 4.2 mm, a width of 0.6 mm, and a height of 2 mm.

[0040] Comparative Example 1

[0041] The difference from Embodiment 1 is that the first high-impedance metasurface 2 and the second high-impedance metasurface 3 are not loaded.

[0042] Comparative Example 2

[0043] The difference from Embodiment 1 is that the first three-dimensional structural layer 1 is not included.

[0044] Comparative Example 3

[0045] The difference from Embodiment 1 is that it does not include the first three-dimensional structural layer 1 and does not have the third high-impedance metasurface 4 loaded.

[0046] Test

[0047] The three-dimensional absorbing metamaterial prepared in Example 1 was analyzed for its structure and working characteristics using simulation software. The results of the TE wave reflection coefficient changing with frequency at different incident angles are as follows: Figure 6 As shown in the figure, the results of the TE wave absorption rate changing with frequency for different incident angles are as follows: Figure 7 As shown, the TM wave reflection coefficient varies with frequency for different incident angles. Figure 8 As shown, the TM wave absorption rate varies with frequency for different incident angles. Figure 9 As shown.

[0048] The materials prepared in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 were analyzed for their structural and operational characteristics using simulation software. The comparison results of the reflectivity curves for electromagnetic wave perpendicular incidence in Example 1 and Comparative Example 1 are shown below. Figure 10 As shown in the figure, the results of TE reflectivity versus frequency for different incident angles in Comparative Example 1 are as follows: Figure 11 As shown in the figure, the results of TE reflectivity variation with frequency for different incident angles in Comparative Example 2 are as follows: Figure 12 As shown in the figure, the results of TE reflectivity variation with frequency for different incident angles in the three comparative examples are as follows: Figure 13 As shown.

[0049] Depend on Figure 6 It can be seen that when electromagnetic waves are incident perpendicularly, the frequency band with reflectivity below -10dB is 7.9GHz-40.0GHz; when the incident angle of electromagnetic waves is 45°, the frequency band with reflectivity below -10dB is 9.4GHz-40.0GHz; and when the incident angle of electromagnetic waves is 60°, the frequency band with reflectivity below -10dB is 18.8GHz-33.7GHz.

[0050] At the same time Figure 7 It can be seen that 90% of the absorption frequency band is related to Figure 6 The -10dB reflection coefficient corresponds to the frequency band.

[0051] Depend on Figure 8 It can be seen that when electromagnetic waves are incident perpendicularly, the frequency band with reflectivity below -10dB is 7.9GHz-40.0GHz; when the incident angle of electromagnetic waves is 45°, the frequency band with reflectivity below -10dB is 11.9GHz–40.0GHz.

[0052] At the same time Figure 9 It can be seen that 90% of the absorption frequency band is related to Figure 8 The -10dB reflection coefficient corresponds to the frequency band.

[0053] Depend on Figure 10It can be seen that when the first high-impedance metasurface 2 and the second high-impedance metasurface 3 are loaded at a specific position of the first three-dimensional structural layer 1, the frequency band with reflectivity below -10dB is 7.9GHz-40.0GHz; when the first high-impedance metasurface 2 and the second high-impedance metasurface 3 are not loaded at a specific position of the first three-dimensional structural layer 1, the frequency band with reflectivity below -10dB is 11.0GHz-24.8GHz.

[0054] Depend on Figure 11 It can be seen that, under vertical incidence, the frequency band with reflectivity below -10dB is 11.0GHz-24.8GHz. As the incident angle increases, the absorption bandwidth gradually decreases. When the incident angle is 60°, the frequency band with reflectivity below -10dB is 14.5GHz-24.8GHz.

[0055] Depend on Figure 12 It can be seen that, under perpendicular incidence, the frequency band with reflectivity below -10dB is 20.4GHz-40.0GHz, and there is no absorption band below -10dB when the incident angle increases to 60°.

[0056] Depend on Figure 13 It is known that the absorber has almost no performance when the first three-dimensional structural layer 1 and its specific locations are not loaded with the first high-impedance metasurface 2 and the second high-impedance metasurface 3, and the top layer of the second three-dimensional structural layer 5 is not loaded with the third high-impedance metasurface 4.

[0057] Therefore, the present invention employs the aforementioned three-dimensional structure absorbing metamaterial, which can achieve ultra-wideband absorption and large-angle stability at a relatively thin thickness, which is beneficial for the lightweight and thin broadband application of the absorber and has great practical value in the field of electromagnetic compatibility.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A three-dimensional structured wave-absorbing metamaterial, characterized in that: It includes a first three-dimensional structural layer, a second three-dimensional structural layer and a metal backplate arranged from top to bottom. The first three-dimensional structural layer includes a first top layer and a first three-dimensional absorption and enhancement skeleton disposed on the lower surface of the first top layer. The lower surface of the first three-dimensional absorption and enhancement skeleton is loaded with a first high-impedance metasurface and a second high-impedance metasurface at intervals. The second three-dimensional structural layer includes a second top layer and a second three-dimensional absorption and enhancement skeleton disposed on the lower surface of the second top layer. A third high-impedance metasurface is loaded on the top surface of the second top layer. The first three-dimensional absorption enhancement framework is a densely packed, hollow, stepped, hexagonal prism-shaped structure. The second three-dimensional absorption enhancement framework is a single hollow regular hexagonal prism structure; The first high-resistivity metasurface, the second high-resistivity metasurface, and the third high-resistivity metasurface are all made of resistive ink, with a sheet resistance of 50-300 ohm / sq.

2. The three-dimensional structure wave-absorbing metamaterial of claim 1, wherein: The first three-dimensional absorption-enhancing skeleton has 3-6 coaxial hollow regular hexagonal prisms, wherein the smallest hollow regular hexagonal prism has a side length of 2mm-4mm and a height of 0.2mm-1.5mm, the width of the coaxial hollow regular hexagonal prism is 0.4mm-1mm, and the height gradient of the coaxial hollow regular hexagonal prism is 0.3mm-1.0mm.

3. The three-dimensional structure wave-absorbing metamaterial of claim 1, wherein: The first three-dimensional structural layer and the second three-dimensional structural layer are both made of one of the following materials: carbon-based absorbent, polymer absorbent, and ceramic-based absorbent, with a dielectric constant between 2.0 and 5.

0.

4. The three-dimensional structure wave-absorbing metamaterial of claim 1, wherein: The first top layer, the second top layer, and the metal back plate are all regular hexagonal structures. The side length of the first top layer and the second top layer are both 4.5mm-12.0mm, and the thickness is both 0.1mm-0.3mm.

5. The three-dimensional structure wave-absorbing metamaterial of claim 1, wherein: The second three-dimensional absorption-enhancing skeleton has a side length of 2.0mm-8.0mm, a width of 0.4mm-1.5mm, and a height of 1.2mm-3.6mm.

6. The three-dimensional structured microwave absorbing metamaterial according to claim 1, characterized in that: The first high-impedance metasurface, the second high-impedance metasurface, and the third high-impedance metasurface are all prepared on the first three-dimensional structural layer or the second three-dimensional structural layer by one of screen printing, mechanical engraving, or magnetron sputtering.

7. The three-dimensional structure wave-absorbing metamaterial of claim 1, wherein: Both the first three-dimensional structural layer and the second three-dimensional structural layer are formed using fused deposition modeling (FDM) technology.

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