Wave-absorbing metamaterial with three-dimensional structure

Abstract

The invention belongs to the technical field of electromagnetic wave absorption, and particularly discloses a three-dimensional structure wave-absorbing metamaterial which comprises a first three-dimensional structure layer, a second three-dimensional structure layer and a metal backboard which are sequentially arranged from top to bottom, the first three-dimensional structure layer comprises a first top layer and a first three-dimensional absorption enhancing framework arranged on the lower surface of the first top layer, and the second three-dimensional structure layer comprises a second top layer and a second three-dimensional absorption enhancing framework arranged on the lower surface of the second top layer. A first high-impedance metasurface and a second high-impedance metasurface are loaded on the lower surface of the first three-dimensional absorption enhancement skeleton at intervals; the second three-dimensional structure layer comprises a second top layer and a second three-dimensional absorption enhancement skeleton arranged 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. By adopting the three-dimensional structure wave-absorbing metamaterial, ultra-wideband absorption and large-angle stability can be achieved under the condition that the thickness is small, light and thin wideband application of a wave-absorbing body is facilitated, and the three-dimensional structure wave-absorbing metamaterial has great practical value in the field of electromagnetic compatibility.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic wave absorption technology, and in particular to a three-dimensional structured wave absorbing metamaterial. Background Art

[0002] The rapid development and widespread application of electronic information technology have greatly facilitated people's lives, but the hazards brought by various electromagnetic pollution have become increasingly significant. Electromagnetic absorption materials are one of the effective ways to solve this problem. In practical applications, with the continuous advancement of the engineering application of resonant absorbing structures, the requirements for integration with the mechanical properties of structural parts, conformal conformity of irregular surfaces, and flexibility in the design of finite thickness absorbing performance have gradually increased, which has raised new problems for the manufacturing methods of absorbing materials. In addition, the traditional circuit simulation absorber based on resistive frequency selective surface, the middle spacer layer is usually an air layer or a lightweight foam material, which basically has no mechanical properties and it is difficult to achieve common loading of the surface. The characteristics of 3D printing layer-by-layer cumulative forming and the insensitivity of manufacturing cost to the complexity of the shape provide a feasible solution to this problem.

[0003] The structural designability of 3D printing technology is an important advantage in material molding. Through simple 3D printing, any structural sample can be molded without the need for additional design and manufacturing of molds. For electromagnetic absorbing materials, 3D structures help reduce the density of electromagnetic absorbing materials and cause electromagnetic waves to reflect multiple times in porous structures. The absorbing composite material obtained by combining 3D absorbing structures with resistive frequency selective surfaces provides a new possibility for achieving high-performance absorption. Summary of the invention

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

[0005] To achieve the above-mentioned object, the present invention provides a three-dimensional structured absorbing metamaterial, comprising a first three-dimensional structure layer, a second three-dimensional structure layer and a metal backplane arranged in sequence from top to bottom, wherein the first three-dimensional structure layer comprises a first top layer and a first three-dimensional absorption enhancement skeleton arranged on the lower surface of the first top layer, and the lower surface of the first three-dimensional absorption enhancement skeleton is alternately loaded with a first high-impedance metasurface and a second high-impedance metasurface;

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

[0007] Preferably, the first three-dimensional absorption enhancement skeleton is a plurality of closely-packed regular hexagonal hollow stepped gradient structures.

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

[0009] Preferably, the materials of the first three-dimensional structure layer and the second three-dimensional structure layer are both one of carbon-based absorbents, polymer absorbents, and ceramic-based absorbents, and their dielectric constants are between 2.0 and 5.0.

[0010] Preferably, the first top layer, the second top layer, and the metal backplane are all regular hexagonal structures, the side lengths of the first top layer and the second top layer are both 4.5 mm - 12.0 mm, and the thicknesses are both 0.1 mm - 0.3 mm.

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

[0012] Preferably, the side length of the second three-dimensional absorption enhancement framework is 2.0 mm - 8.0 mm, the width is 0.4 mm - 1.5 mm, and the height is 1.2 mm - 3.6 mm.

[0013] Preferably, the materials of the first high-impedance metasurface, the second high-impedance metasurface, and the third high-impedance metasurface are all resistive inks, and their sheet resistance is 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 structure layer or the second three-dimensional structure layer by one of screen printing, mechanical engraving, or magnetron sputtering.

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

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

[0017] (1) For the three-dimensional structured microwave absorbing metamaterial prepared by the present invention, under TE polarization, when the electromagnetic wave is incident perpendicularly, the frequency band with a reflectivity lower than -10 dB is 7.9 GHz - 40.0 GHz, and the relative bandwidth is 134.0%; when the incident angle of the electromagnetic wave is 45°, the frequency band with a reflectivity lower than -10 dB is 9.4 GHz - 40 GHz, and the relative bandwidth is 123.9%; when the incident angle of the electromagnetic wave is 60°, the reflectivity is lower than -10 dB in the range of 18.8 GHz - 33.7 GHz, with an absorption bandwidth of 14.9 GHz.

[0018] (2) Through the three-dimensional structure design, the present invention provides multiple loading interfaces for the high-impedance metasurface, and prints the high-impedance metasurface on the three-dimensional structure, realizing stable broadband microwave absorbing performance at oblique incident angles and excellent mechanical properties, that is, it can have ultra-wideband absorption and large-angle stability at a relatively thin thickness, which is conducive to the integration of functional structures and the thin and wideband application of microwave absorbers, and 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. Description of the Drawings

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

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

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

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

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

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

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

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

[0028] Figure 9 It is a graph showing the variation of the TM wave absorption rate with frequency corresponding to different incident angles in an embodiment of a three-dimensional structured absorbing metamaterial of the present invention;

[0029] Figure 10 It is a comparison graph of the reflectivity curves when electromagnetic waves are vertically incident in an embodiment and Comparative Example 1 of a three-dimensional structured absorbing metamaterial of the present invention;

[0030] Figure 11 It is a graph showing the variation of the TE reflectivity with frequency corresponding to different incident angles in Comparative Example 1 of a three-dimensional structured absorbing metamaterial of the present invention;

[0031] Figure 12 It is a graph showing the variation of the TE reflectivity with frequency corresponding to different incident angles in Comparative Example 2 of a three-dimensional structured absorbing metamaterial of the present invention;

[0032] Figure 13 It is a graph showing the variation of the TE reflectivity with frequency corresponding to different incident angles in Comparative Example 3 of a three-dimensional structured absorbing metamaterial of the present invention.

[0033] Reference numerals

[0034] 1. First three-dimensional structure layer; 2. First high-impedance metasurface; 3. Second high-impedance metasurface; 4. Third high-impedance metasurface; 5. Second three-dimensional structure layer; 6. Metal backplane; 7. First three-dimensional absorption enhancement framework; 8. First top layer; 9. Second top layer; 10. Second three-dimensional absorption enhancement framework. Detailed implementation manners

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

[0036] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings understood by those of ordinary skill in the field to which the present invention belongs.

[0037] Embodiment 1

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

[0039] In this embodiment, the materials of the first three-dimensional structure layer 1 and the second three-dimensional structure layer 5 are both polymer absorbers, and their dielectric constant is 3.2. The first three-dimensional structure layer 1 and the second three-dimensional structure layer 5 are both formed by fused deposition technology. The materials of the first high-impedance metasurface 2, the second high-impedance metasurface 3, and the third high-impedance metasurface 4 are all resistive inks, and their sheet resistance is 50 ohm / sq. They are prepared on the first three-dimensional structure layer 1 or the second three-dimensional structure layer 5 by screen printing. The first top layer 8, the second top layer 9, and the metal backplane 6 are all regular hexagonal structures. The side lengths of the first top layer 8 and the second top layer 9 are both 4.96 mm, and the thicknesses are both 0.2 mm. The number of coaxial hollow regular hexagonal prisms of the first three-dimensional absorption enhancement framework 7 is 4. The side length of the smallest hollow regular hexagonal prism is 2.12 mm, the height is 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 side length of the second three-dimensional absorption enhancement framework 10 is 4.2 mm, the width is 0.6 mm, and the height is 2 mm.

[0040] Comparative Example 1

[0041] The difference from Example 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 Example 1 is that the first three-dimensional structure layer 1 is not included.

[0044] Comparative Example 3

[0045] The difference from Example 1 is that the first three-dimensional structure layer 1 is not included, and the third high-impedance metasurface 4 is not loaded.

[0046] Experimental Test

[0047] The three-dimensional structural microwave 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 varying with frequency corresponding to different incident angles are as Figure 6 shown, and the results of the TE wave absorption rate varying with frequency corresponding to different incident angles are as Figure 7 shown. The results of the TM wave reflection coefficient varying with frequency corresponding to different incident angles are as Figure 8 shown, and the results of the TM wave absorption rate varying with frequency corresponding to different incident angles are as Figure 9 shown.

[0048] The structures and working characteristics of the materials prepared in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 were analyzed using simulation software. The comparison results of the reflectivity curves when electromagnetic waves are vertically incident in the two states of Example 1 and Comparative Example 1 are as Figure 10 shown. The results of the TE reflectivity varying with frequency corresponding to different incident angles in Comparative Example 1 are as Figure 11 shown. The results of the TE reflectivity varying with frequency corresponding to different incident angles in Comparative Example 2 are as Figure 12 shown. The results of the TE reflectivity varying with frequency corresponding to different incident angles in Comparative Example 3 are as Figure 13 shown.

[0049] It can be Figure 6 seen that when electromagnetic waves are vertically incident, the frequency band with a reflectivity lower than -10 dB is 7.9 GHz - 40.0 GHz; when the incident angle of the electromagnetic wave is 45°, the frequency band with a reflectivity lower than -10 dB is 9.4 GHz - 40.0 GHz; when the incident angle of the electromagnetic wave is 60°, the frequency band with a reflectivity lower than -10 dB is 18.8 GHz - 33.7 GHz.

[0050] At the same time, it can be Figure 7 seen that the 90% absorption frequency band corresponds to the Figure 6 -10 dB reflection coefficient frequency band in

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

[0052] At the same time, it can be Figure 9 seen that the 90% absorption frequency band corresponds to the Figure 8 -10 dB reflection coefficient frequency band in

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

[0054] It can be known from Figure 11 that when the incident angle is perpendicular, the frequency band with a reflectivity lower than -10 dB is 11.0 GHz - 24.8 GHz. As the incident angle increases, the absorption bandwidth gradually decreases. When the incident angle is 60°, the frequency band with a reflectivity lower than -10 dB is 14.5 GHz - 24.8 GHz.

[0055] It can be known from Figure 12 that when the incident angle is perpendicular, the frequency band with a reflectivity lower than -10 dB is 20.4 GHz - 40.0 GHz. When the incident angle increases to 60°, there is no absorption frequency band lower than -10 dB.

[0056] It can be known from Figure 13 that excluding the first three-dimensional structure layer 1 and its specific positions where the first high-impedance metasurface 2 and the second high-impedance metasurface 3 are not loaded, and when the third high-impedance metasurface 4 is not loaded on the top layer of the second three-dimensional structure layer 5, the absorber has almost no performance.

[0057] Therefore, by adopting the above three-dimensional structure absorbing metamaterial, the present invention can have ultra-wideband absorption and large-angle stability at a relatively thin thickness, which is beneficial to the lightweight and wideband 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 are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A three-dimensional structured microwave absorbing metamaterial, characterized in that: It includes a first three-dimensional structure layer, a second three-dimensional structure layer, and a metal backplane arranged in sequence from top to bottom. The first three-dimensional structure layer includes a first top layer and a first three-dimensional absorption enhancement framework disposed on the lower surface of the first top layer. The lower surface of the first three-dimensional absorption enhancement framework is loaded with a first high-impedance metasurface and a second high-impedance metasurface at intervals. The second three-dimensional structure layer includes a second top layer and a second three-dimensional absorption enhancement framework disposed on the lower surface of the second top layer. The top surface of the second top layer is loaded with a third high-impedance metasurface.

2. The three-dimensional structured microwave absorbing metamaterial according to claim 1, wherein: The first three-dimensional absorption enhancement framework is a densely paved plurality of regular hexagonal prism hollow stepped gradient structures.

3. The three-dimensional structured microwave absorbing metamaterial according to claim 2, wherein: The number of coaxial hollow regular hexagonal prisms of the first three-dimensional absorption enhancement framework is 3 - 6. The side length of the smallest hollow regular hexagonal prism is 2 mm - 4 mm, the height is 0.2 mm - 1.5 mm, the width of the coaxial hollow regular hexagonal prism is 0.4 mm - 1 mm, and the height gradient of the coaxial hollow regular hexagonal prism is 0.3 mm - 1.0 mm.

4. A three-dimensional structured microwave absorbing metamaterial according to claim 1, characterized in that: The materials of the first three-dimensional structure layer and the second three-dimensional structure layer are both one of carbon-based absorbents, polymer absorbents, and ceramic-based absorbents, and their dielectric constants are between 2.0 and 5.

0.

5. The three-dimensional structured microwave absorbing metamaterial according to claim 1, wherein: The first top layer, the second top layer, and the metal backplane are all regular hexagonal structures. The side lengths of the first top layer and the second top layer are both 4.5 mm - 12.0 mm, and the thicknesses are both 0.1 mm - 0.3 mm.

6. The three-dimensional structured microwave absorbing metamaterial according to claim 1, wherein: The second three-dimensional absorption enhancement framework is a single hollow regular hexagonal prism structure.

7. The three-dimensional structured microwave absorbing metamaterial according to claim 6, wherein: The side length of the second three-dimensional absorption enhancement framework is 2.0 mm - 8.0 mm, the width is 0.4 mm - 1.5 mm, and the height is 1.2 mm - 3.6 mm.

8. The three-dimensional structured microwave absorbing metamaterial according to claim 1, wherein: The materials of the first high-impedance metasurface, the second high-impedance metasurface, and the third high-impedance metasurface are all resistive inks, and their sheet resistance is 50 - 300 ohm / sq.

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

10. The three-dimensional structured microwave absorbing metamaterial according to claim 1, wherein: The first three-dimensional structure layer and the second three-dimensional structure layer are both formed by fused deposition technology.

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