A miniaturized single-layer ultra-thin ultra-surface absorber

Abstract

The present invention belongs to the technical field of electromagnetic energy absorption, and in particular to a miniaturized single-layer ultra-thin supersurface absorber comprising a supersurface absorption layer, a dielectric layer and a metal floor layer; the supersurface absorption layer is composed of four rotationally symmetrical herringbone gap structures, and adjacent supersurface absorption layers are connected by resistors; the dielectric layer is located below the supersurface absorption layer and is composed of a material with a high dielectric constant and a low loss tangent; the metal floor layer is located below the dielectric layer and is used to reflect absorbed electromagnetic waves; the present invention adopts a single-layer supersurface absorber with the above structure, based on the idea of ​​simplifying the complex, uses resistors to connect adjacent supersurface absorber layers, so that the supersurface absorber becomes a whole, which not only reduces the size of the entire supersurface absorber, but also reduces the number of resistor elements used. The present invention has polarization insensitivity and wide incident angle coverage performance, and has broad application prospects in the fields of stealth technology, integrated equipment and energy collection.

Description

Technical Field

[0001] The invention relates to the technical field of electromagnetic energy absorption, in particular to a miniaturized single-layer ultra-thin ultra-surface absorber. Background Art

[0002] With the rapid development of wireless electronic countermeasure technology and high-frequency equipment, and the continuous popularization and promotion of electronic devices such as smart homes, more and more electromagnetic waves are radiated in free space, including useful frequency bands that carry information, useless frequency bands that pollute the environment, and hostile frequency bands for enemy detection. Therefore, energy utilization and electromagnetic shielding technology have begun to be valued in various fields.

[0003] The main method currently used in electromagnetic absorption technology is to design high-efficiency absorbers for electromagnetic absorption. Traditional absorbers are limited in size, thickness, polarization insensitivity and absorption efficiency. In recent years, with the application of metamaterials, planar electromagnetic metasurfaces have nearly perfect absorption efficiency. The use of electromagnetic metasurfaces can break through the limitations of traditional absorbers.

[0004] At present, researchers have made many attempts to reduce the size, thickness and number of resistors of the absorber, and have designed multi-layer metasurface absorbers and single-layer metasurface absorbers. However, multi-layer metasurface absorbers require the setting of air layers or multiple dielectric layers, which increases the volume and number of resistors of the absorber; single-layer metasurface absorbers can effectively reduce the volume, but still require a large number of resistors, and lack research on polarization insensitivity and wide incident angle stability. Therefore, research on miniaturized single-layer high-performance metasurface absorbers is very necessary. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the shortcomings of the prior art, the present invention provides a miniaturized single-layer ultra-thin ultra-surface absorber to solve the problems of the existing absorbers such as large size, wide thickness, large number of loaded resistors, and unstable absorption at a wide incident angle.

[0007] (II) Technical solution

[0008] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0009] A miniaturized single-layer ultra-thin supersurface absorber, the absorber includes a supersurface absorption layer, a dielectric layer and a metal floor layer from top to bottom, the supersurface absorption layer is composed of an absorption metal patch and a resistor, the absorption metal patch includes a herringbone gap, a rectangular microstrip line, an arrow-shaped patch and a central square patch, wherein;

[0010] The herringbone gap is composed of four rotationally symmetrical herringbone gaps, which are located at the center of each side of the absorbing metal patch, with the head end starting from the edge of the absorbing metal patch and the tail end reaching the central square patch. Each herringbone gap includes two groups of mutually symmetrical rectangular gaps and annular gaps. The rectangular gaps are located on both sides of the microstrip line and are placed perpendicular to the side length of the absorbing metal patch. The annular gap is located at the top of the rectangular gap, and is extended in an annular manner to both sides starting from the rectangular gaps on both sides, intersecting with the rectangular gaps and being tangent to the side length of the absorbing metal patch.

[0011] The rectangular microstrip line is located symmetrically between the rectangular gap and the annular gap, and is used to connect the resistor and the central square patch;

[0012] The arrow-shaped patch is arranged at the four corner vertices of the absorption type metal patch in a rotationally symmetrical manner, and an annular gap is arranged inside the arrow-shaped patch;

[0013] The central square patch is located at the center of the absorbing metal patch and is connected to the rectangular microstrip line;

[0014] The resistor is located at the end center of the rectangular microstrip line of adjacent absorbing metal patches in a rotationally symmetrical manner, and is used to connect adjacent absorbing metal patches to form an integrated supersurface absorption layer.

[0015] Furthermore, the super surface absorption layer is a rotationally symmetrical structure with a side length of 11 mm to 11.8 mm;

[0016] The rotational symmetry angle of the herringbone gap is 90°, the length of the rectangular gap is 3mm-3.6mm, and the width is 0.3mm-0.5mm. The length of the rectangular gap can be changed to adjust the wave absorption frequency band. The angle of the annular gap is 10°-30°, and the width is 0.2mm-0.6mm.

[0017] The length of the rectangular microstrip line is 3mm-3.6mm and the width is 0.8mm-1.2mm;

[0018] The angle of rotational symmetry of the arrow-shaped patch is 90°;

[0019] The resistance value of the resistor is 300Ω-550Ω, and the gap width of the loading resistor is 0.6mm-1mm.

[0020] Furthermore, the dielectric layer has a thickness of 1 mm to 2 mm, a relative dielectric constant of 3 to 5, and a loss tangent of 0.0002 to 0.0008.

[0021] Furthermore, the material of the super surface absorption layer and the metal floor layer are both gold or copper, with a thickness of 0.03mm-0.04mm.

[0022] Furthermore, the absorber is a periodically arranged structure, the number of periodic rows is ≥8, the number of periodic columns is ≥8, and resistors are placed at the center of every two adjacent periodic units.

[0023] (III) Beneficial effects

[0024] Compared with the prior art, the present invention provides a miniaturized single-layer ultra-thin ultra-surface absorber, which has the following beneficial effects:

[0025] By designing a rotationally symmetric herringbone slot structure, absorption stability at incident polarization angles of 0°-90° is achieved. For electromagnetic waves with different oblique incident angles, when the incident angle is 0-45°, the absorption efficiency is not less than 95%. When the incident angle reaches 60°, the absorption efficiency exceeds 80%, which is higher than other current single-layer absorbers.

[0026] By setting the resistor to be loaded between adjacent absorbing layer units, all absorber units are connected to form a whole, which not only reduces the design size to a certain extent, but also greatly reduces the number of resistor elements used. On average, one unit uses one resistor, and the resistor utilization rate is much lower than that of other current absorbers.

[0027] By designing a miniaturized single-layer ultra-thin ultra-surface absorber, the absorber unit size of the present invention is only 0.2λ×0.2λ, and the thickness is only 0.026λ, where λ is the lowest absorption frequency. The unit size and thickness are both lower than other current absorbers. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of a unit structure of a miniaturized single-layer ultra-thin ultra-surface absorber of the present invention;

[0029] Figure 2 for Figure 1 A top view of

[0030] Figure 3 This is a schematic diagram of a 4-unit structure of a miniaturized single-layer ultra-thin ultra-surface absorber of the present invention;

[0031] Figure 4 This is an overall schematic diagram of an 8×8 array metasurface absorber in an embodiment of the present invention;

[0032] Figure 5 is a graph showing the variation of the absorption efficiency with frequency corresponding to different polarization angles in an embodiment of the present invention;

[0033] Figure 6 is a graph showing how the absorption efficiency changes with frequency at different incident angles in an embodiment of the present invention;

[0034] Figure 7 A schematic diagram of an experiment to test the wave absorbing performance of an embodiment of the present invention;

[0035] Figure 8 The embodiment of the present invention and the metal plate Figure 7 Comparison chart of S21 measured under test environment.

[0036] In the figure: 1. Supersurface absorption layer; 2. Dielectric layer; 3. Metal floor layer; 4. Herringbone gap; 5. Rectangular gap; 6. Annular gap; 7. Rectangular microstrip line; 8. Resistor; 9. Absorption metal patch; 10. Arrow-shaped patch; 11. Center square patch. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Example

[0039] In this experimental example, simulation software is used to analyze the miniaturized single-layer ultra-thin ultra-surface absorbing structure prepared in this embodiment to explain the working characteristics of the structure.

[0040] like Figure 1-3 As shown, a miniaturized single-layer ultra-thin supersurface absorber proposed in Embodiment 1 of the present invention includes a supersurface absorption layer 1, a dielectric layer 2 and a metal floor layer 3 from top to bottom. The supersurface absorption layer 1 is composed of an absorption type metal patch 9 and a resistor 8. The absorption type metal patch 9 includes a herringbone gap 4, a rectangular microstrip line 7, an arrow-shaped patch 10 and a central square patch 11. The herringbone gap 4 is composed of 4 rotationally symmetrical herringbone gaps 4, which are located at the center of each side of the absorption type metal patch 9, with the head end starting from the edge of the absorption type metal patch 9 and the tail end to the central square patch 11. The herringbone slot 4 includes two groups of mutually symmetrical rectangular slots 5 and annular slots 6. The rectangular slots 5 are located on both sides of the rectangular microstrip line 7 and are placed perpendicular to the side length of the absorbing metal patch 9. The annular slot 6 is located at the top of the rectangular slot 5. It takes the rectangular slots 5 on both sides as the starting point and extends to both sides in a circular manner, intersecting with the rectangular slots 5 and being tangent to the side length of the absorbing metal patch 9. By setting the rotationally symmetrical herringbone slots 4, stable absorption of polarization angles of 0-90° and incident angles of 0-60° can be achieved, and the absorbing frequency band of the absorber can be controlled by adjusting the length of the rectangular slots 5, which has a frequency adjustable function.

[0041] The rectangular microstrip line 7 is located symmetrically between the rectangular gap 5 and the annular gap 6, and is used to connect the resistor 8 and the central square patch 11;

[0042] The arrow-shaped patch 10 is arranged at the four corner vertices of the absorption metal patch 9 in a rotationally symmetrical manner, and an annular gap 6 is arranged inside the arrow-shaped patch 10;

[0043] The central square patch 11 is located at the center of the absorbing metal patch 9 and is connected to the rectangular microstrip line 7;

[0044] The resistor 8 is located at the center position of the end point of the rectangular microstrip line 7 of the adjacent absorbing metal patch 9 in a rotationally symmetrical manner, and is used to connect the adjacent absorbing metal patches 9 to form an integrated metasurface absorption layer 1; the periodic metasurface absorber is made into a whole through the above-mentioned resistor 8 loading method, the absorption capacity of the absorber is enhanced, the usage rate of the resistor 8 is greatly reduced, and on average one absorbing unit uses one resistor 8, while the size of the absorber is reduced.

[0045] The preferred metasurface absorption layer 1 is a rotationally symmetrical structure with a side length of 11.4 mm, which is only 0.026λ, smaller than the size of the current single-layer absorber;

[0046] The rotational symmetry angle of the herringbone gap 4 is 90°, the length of the rectangular gap 5 is 3.3 mm, and the width is 0.4 mm. The wave absorbing frequency band can be adjusted by changing the length of the rectangular gap 5. The angle of the annular gap 6 is 10°, and the width is 0.4 mm.

[0047] The rectangular microstrip line 7 has a length of 3.3 mm and a width of 1 mm.

[0048] The angle of rotational symmetry of the arrow-shaped patch 10 is 90°;

[0049] The resistance value of the resistor 8 is 450Ω, and the gap width of the loading resistor 8 is 0.8 mm.

[0050] The relative dielectric constant of the preferred dielectric layer 2 material is 3, the loss tangent is 0.0008, and the thickness of the dielectric layer 2 is 1.5 mm, which is only 0.2λ, lower than the thickness of the current single-layer absorber. The use of high dielectric constant and low-loss dielectric materials can reduce the unit size, and the low-loss dielectric material does not lose the energy of the incident electromagnetic wave, so the incident electromagnetic wave is completely absorbed by the surface super-surface absorption layer 1, and the absorbed energy can be collected through the metal on the surface of the absorption layer, expanding the application field of the absorber.

[0051] Preferably, the material of the super surface absorption layer 1 and the metal floor layer 3 is gold or copper, and the thickness is 0.035 mm.

[0052] Figure 4 The 8×8 periodic array metasurface absorber designed for the first embodiment of the present invention has 8 periodic rows and 8 periodic columns, and a resistor 8 is placed at the center of every two adjacent periodic units.

[0053] Figure 5 The graph of the wave absorption efficiency corresponding to different polarization angles in the embodiment of the present invention as a function of frequency shows that when the incident polarization angle changes in the range of 0-90°, the wave absorption efficiency can reach nearly 100%, proving that the present invention has polarization insensitivity.

[0054] Figure 6 This is a graph showing how the absorption efficiency varies with frequency for different incident angles in an embodiment of the present invention. It can be seen that when the incident angle varies in the range of 0-60°, when the incident angle is 0-45°, the absorption efficiency is not less than 95%, and when the incident angle reaches 60°, the absorption efficiency exceeds 80%, proving that the present invention has wide incident angle stability.

[0055] Figure 7 A schematic diagram of an experiment to test the absorbing performance of an embodiment of the present invention is shown. Two horn antennas are facing the absorbing body of the present invention, one horn antenna is a transmitting antenna, and the other is a receiving antenna. The absorbing performance of the absorbing body can be determined based on S21 measured by the receiving antenna.

[0056] Figure 8 The embodiment of the present invention and the metal plate Figure 7 From the S21 comparison chart obtained under the test environment, it can be seen that the embodiment of the present invention can absorb most of the incident wave energy, verifying the wave absorbing performance of the embodiment of the present invention.

[0057] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A miniaturized single-layer ultra-thin ultra-surface absorber, characterized in that: The absorber includes a metasurface absorption layer, a dielectric layer and a metal floor layer from top to bottom. The metasurface absorption layer is composed of an absorption metal patch and a resistor. The absorption metal patch includes a herringbone gap, a rectangular microstrip line, an arrow-shaped patch and a central square patch, wherein; The herringbone gap is composed of four rotationally symmetrical herringbone gaps, which are located at the center of each side of the absorbing metal patch, with the head end starting from the edge of the absorbing metal patch and the tail end reaching the central square patch. Each herringbone gap includes two groups of mutually symmetrical rectangular gaps and annular gaps. The rectangular gaps are located on both sides of the microstrip line and are placed perpendicular to the side length of the absorbing metal patch. The annular gap is located at the top of the rectangular gap, and is extended in an annular manner to both sides starting from the rectangular gaps on both sides, intersecting with the rectangular gaps and being tangent to the side length of the absorbing metal patch. The rectangular microstrip line is located symmetrically between the rectangular gap and the annular gap, and is used to connect the resistor and the central square patch; The arrow-shaped patch is arranged at the four corner vertices of the absorption type metal patch in a rotationally symmetrical manner, and an annular gap is arranged inside the arrow-shaped patch; The central square patch is located at the center of the absorbing metal patch and is connected to the rectangular microstrip line; The resistor is located at the end center of the rectangular microstrip line of adjacent absorbing metal patches in a rotationally symmetrical manner, and is used to connect adjacent absorbing metal patches to form an integrated supersurface absorption layer.

2. The miniaturized single-layer ultra-thin ultra-surface absorber according to claim 1, characterized in that: The super surface absorption layer is a rotationally symmetrical structure with a side length of 11mm-11.8mm; The rotational symmetry angle of the herringbone gap is 90°, the length of the rectangular gap is 3mm-3.6mm, and the width is 0.3mm-0.5mm. The length of the rectangular gap can be changed to adjust the wave absorption frequency band. The angle of the annular gap is 10°-30°, and the width is 0.2mm-0.6mm. The length of the rectangular microstrip line is 3mm-3.6mm and the width is 0.8mm-1.2mm; The angle of rotational symmetry of the arrow-shaped patch is 90°; The resistance value of the resistor is 300Ω-550Ω, and the gap width of the loading resistor is 0.6mm-1mm.

3. The miniaturized single-layer ultra-thin ultra-surface absorber according to claim 1, characterized in that: The dielectric layer has a thickness of 1 mm to 2 mm, a relative dielectric constant of 3 to 5, and a loss tangent of 0.0002 to 0.0008.

4. The miniaturized single-layer ultra-thin ultra-surface absorber according to claim 1, characterized in that: The material of the super surface absorption layer and the metal floor layer are both gold or copper, and the thickness is 0.03mm-0.04mm.

5. The miniaturized single-layer ultra-thin ultra-surface absorber according to claim 1, characterized in that: The wave absorbing body is a periodically arranged structure, the number of periodic rows is ≥8, the number of periodic columns is ≥8, and resistors are placed at the center of every two adjacent periodic units.

Images