WO2017157217A1

WO2017157217A1 - Wave-absorbing metamaterial, antenna cover and antenna system

Info

Publication number: WO2017157217A1
Application number: PCT/CN2017/076108
Authority: WO
Inventors: 刘若鹏; 周添
Original assignee: 深圳光启高等理工研究院
Priority date: 2016-03-16
Filing date: 2017-03-09
Publication date: 2017-09-21
Also published as: CN105789912B; CN105789912A

Abstract

A wave-absorbing metamaterial, an antenna cover and an antenna system, capable of realizing reflectivity reduction under the conditions of vertical incidence and large-angle incidence. The wave-absorbing metamaterial comprises a magnetic electromagnetic wave-absorbing material layer (2) and a conductive geometric structure layer combined with the magnetic electromagnetic wave-absorbing material layer (2). The conductive geometric structure layer is composed of a plurality of conductive geometric structure units (1) arranged in sequence. Each of the conductive geometric structure units (1) comprises a non-closed annular conductive geometric structure. Two stripe-shaped structures (10) arranged in parallel relatively are arranged at an opening of the annular conductive geometric structure.

Description

Absorbing metamaterials, radomes and antenna systems

[0001] The present invention relates to electromagnetic wave absorbing materials and radomes and antenna systems therewith.

Background technique

[0002] Conventional absorbing materials, especially rubber-based absorbing absorbing patch materials with high-performance absorbents, achieve electromagnetic absorption and electromagnetic isolation through high magnetic permeability and magnetic loss. However, with high magnetic permeability and high magnetic loss, the dielectric constant of the absorbing material is also relatively high, and the relative dielectric constant in the ^ S band is usually above 15 or higher.

technical problem

[0003] In this case, the reflection of electromagnetic waves on the surface of the absorbing material is severe, which is not conducive to the absorption of electromagnetic waves. Especially at large angles of incidence, the reflection is more severe.

Problem solution

Technical solution

[0004] It is an object of the present invention to provide an absorbing wave metamaterial, a radome, and an antenna system that achieve a reduction in reflectivity under both vertical and large angle incident conditions.

[0005] A absorbing wave metamaterial includes a magnetic electromagnetic absorbing material layer and a conductive geometric layer combined with a magnetic electromagnetic absorbing material layer; the conductive geometric layer is composed of a plurality of conductive geometric units arranged in sequence Each of the conductive geometrical units includes a non-closed annular conductive geometry, and the annular conductive geometric structure is provided with two strip structures that are relatively parallel.

In one embodiment, the annular conductive geometry is provided with more than one of the openings.

In one embodiment, the annular conductive geometry is circular, elliptical, triangular or polygonal.

In one embodiment, the magnetic electromagnetically absorbing material layer has a dielectric constant of 5 to 30 and a magnetic permeability of 1 to 7.

In one embodiment, the conductive geometric units are arranged in a periodic array.

[0010] In an embodiment, the surface of the magnetic electromagnetic wave absorbing material layer is further provided with a metal back plate.

[0011] In an embodiment, the magnetic electromagnetic wave absorbing material layer is an absorbing wave patch material.

[0012] In an embodiment, the conductive geometric unit is attached to the magnetic electromagnetic wave absorbing material layer or embedded Into the magnetic electromagnetic wave absorbing material layer.

[0013] In an embodiment, the magnetic electromagnetic wave absorbing material layer includes a substrate and an absorber bonded to the substrate.

[0014] In an embodiment, the conductive geometric unit is in the shape of a circumscribed circle, and the diameter of the circumscribed circle is 1/20-1/5 of the electromagnetic wavelength of the free space in the working frequency band.

[0015] In an embodiment, the absorbing wave metamaterial has an operating frequency in a frequency range of 0.8-2.7 GHz, and the thickness of the conductive geometric unit is greater than the conductive geometric unit corresponding to the working frequency segment. Skin depth.

[0016] In an embodiment, the absorbing wave metamaterial has an operating frequency in a frequency range of 0.8-2.7 GHz, and the thickness of the metal backing plate is greater than a skin of the metal backing plate corresponding to the working frequency segment. depth.

[0017] In an embodiment, the line width of the annular conductive geometry and the strip structure is W, 0.1 mm≤W<

[0018] In an embodiment, the thickness of the annular conductive geometry and the strip structure is H, 0.005 mm≤H ≤0.05 mm.

[0019] A radome includes any of the absorbing polymeric materials described.

[0020] An antenna system includes any of the absorbing supermaterials described.

[0021] According to the absorbing wave metamaterial of the present invention, the conductive geometric layer in the structure can concentrate the electromagnetic waves in the required operating frequency of the absorbing wave metamaterial, and is convenient for the magnetic electromagnetic absorbing material layer disposed below to be absorbed. The invention can solve the problem of surface reflection of the traditional absorbing material, reduce the surface reflection of the absorbing material, reduce the reflectivity, in particular, can effectively reduce the reflection of the electromagnetic wave perpendicularly incident absorbing material ,, and can effectively reduce the reflection of the 大 material at a large angle. Rate, enhance absorption. Due to the enhanced absorbing effect, the invention can achieve the absorbing effect equivalent to the conventional one under the condition of lighter and thinner conditions, that is, the absorption effect equivalent to the conventional material can be achieved under the condition of lower surface density.

Advantageous effects of the invention

Beneficial effect

[0022] In an embodiment of the invention, the additional metal backing plate reflects the absorbed electromagnetic waves to the magnetic absorbing material layer for secondary absorption to achieve a better absorbing effect.

Brief description of the drawing DRAWINGS

The above and other features, aspects and advantages of the present invention will become more apparent from the following description in conjunction with the appended claims

1 is a schematic view showing a unit of an electromagnetic wave absorbing super material in Embodiment 1 of the present invention;

2 is a schematic view showing an arrangement rule of a plurality of units of an electromagnetic wave absorbing super material in Embodiment 1 of the present invention;

3 is a graph showing reflectance of an electromagnetic wave absorbing super material in a TE mode according to Embodiment 1 of the present invention;

4 is a graph showing reflectance of an electromagnetic wave absorbing super material in a TM mode according to Embodiment 1 of the present invention; [0027] FIG.

5 is a schematic view showing an arrangement rule of a plurality of units of an electromagnetic wave absorbing material in Embodiment 2 of the present invention;

6 is a graph showing reflectance of an electromagnetic wave absorbing super material in TE mode according to Embodiment 2 of the present invention; [0029] FIG.

7 is a graph showing reflectance of an electromagnetic wave absorbing super material in a TM mode according to Embodiment 2 of the present invention; [0030] FIG.

8 is a schematic view showing an arrangement rule of a plurality of units of an electromagnetic wave absorbing super material in Embodiment 3 of the present invention;

9 is a graph showing the reflectance of the electromagnetic wave absorbing super material in the TE mode according to Embodiment 3 of the present invention;

10 is a graph showing reflectance of an electromagnetic wave absorbing super material in a TM mode according to Embodiment 3 of the present invention;

11 is a graph showing reflectance of an electromagnetic wave absorbing material in TE mode in Embodiment 4 of the present invention; [0034] FIG.

12 is a graph showing the reflectance of the electromagnetic wave absorbing supermaterial in the TM mode according to Embodiment 4 of the present invention.

Embodiments of the invention

The invention is further described in the following detailed description and the accompanying drawings, in which For the implementation, a person skilled in the art can make similar promotion and deduction according to the actual application without departing from the connotation of the present invention. Therefore, the scope of the present invention should not be limited by the content of the specific embodiment.

[0037] In the embodiment, the grid is a node of a conductive geometric unit, and a connection between adjacent nodes is formed, which is used to describe the arrangement rule of the conductive geometric unit.

Embodiment 1

As shown in FIG. 1, the absorbing wave metamaterial comprises a magnetic electromagnetic absorbing material layer 2 and a conductive geometric unit 1 combined with the magnetic electromagnetic absorbing material layer 2. The magnetic electromagnetic absorbing material layer 2 may be an electromagnetic wave absorbing agent combined with a rubber as a matrix, and the electromagnetic wave absorbing agent may be absorbed by a granular ferrite or a micro/submicron metal particle. An agent or a magnetic fiber absorbent or a nanomagnetic absorbent which can be incorporated into the rubber matrix by a miscellaneous or proportionate manner. The magnetic electromagnetic absorbing material layer 2 may be a absorbing patch material, has a small thickness and can be automated. The thickness and electromagnetic parameters of the magnetic electromagnetic absorbing material layer 2 can be set according to the working frequency band of the absorbing wave metamaterial, the working frequency range is 0.8-2.7 GHz, and the dielectric constant of the magnetic electromagnetic absorbing material layer 2 is 5-30. The magnetic permeability is 1-7, and the vertical incident reflectance R<-ldB@ lGHz, R<-3dB@2GH z. The conductive geometry unit 1 has a circular shape with two openings, and parallel metal strips 10 are provided at the cornice. As shown in FIG. 2, the arrangement rule of the conductive geometric structure unit 1 is a periodic rule, and the periodic law is periodically arranged in two directions perpendicular to each other in the plane, extending in a square grid form, but the arrangement law is not limited Therefore, it may be a misaligned arrangement or a disordered arrangement or an uneven arrangement. A metal backing plate 3 is also disposed on the back side of the magnetic electromagnetic wave absorbing material layer 2. The metal backing plate 3 is selectively disposed, and in some applications, the metal backing plate 3 may be omitted. The material of the conductive geometric unit 1 may be copper, silver or gold. The thickness of the conductive geometry unit 1 is greater than the skin depth of the working frequency segment. The conductive geometric structure unit 1 and its metal strip 10 have a line width of W and a thickness of H, which can be set to 0.1 mm ≤ W ≤ 1 mm.

0.005 mm ≤ H ≤ 0.05 mm, the conductive geometric unit 1 in this size range has a good absorbing effect. The conductive geometric unit 1 has the shape of a circumscribed circle, and the diameter of the circumscribed circle can be set to 1/20 to 1/5 of the electromagnetic wavelength of the free space in the working frequency band. The circumscribed circle of the conductive geometry unit 1 is a circle defined by itself. In other embodiments, the circumscribed circle may be a circle defined by the outermost endpoint. The thickness of the metal backing plate 3 can be set to be larger than the skin depth of the corresponding operating frequency band. The skin depth is such that when a very high frequency current passes through the conductor, it can be considered that the current flows only in a very thin layer on the surface of the conductor, the thickness of which is the skin depth. When the thickness of the metal backing plate 3 is set with reference to the skin depth, the material of the central portion of the conductor can be omitted.

[0040] The conductive geometric unit 1 may be fixed to the magnetic electromagnetic wave absorbing material layer 2 by a film or a patch, or may be embedded in the magnetic electromagnetic wave absorbing material layer 2. The magnetic electromagnetic absorbing material layer 2 can be bonded or otherwise fixed to the metal backing plate 3.

[0041] The TE wave is a transverse wave in the electromagnetic wave. As shown in FIG. 3, the reflectance in the TE mode decreases as the vertical incidence reflectance of the material increases after the conductive geometric unit is increased, when the diameter lm of the conductive geometric unit 1 is At 3 micron 吋, the reflectivity of the absorbing supermaterial shown in Figure 2 is lower than that of the magnetic electromagnetic absorbing material layer without conductive geometrical elements. When the diameter lm of the conductive geometric unit 1 is 3.5 μm, the absorbing wave The reflectivity of the metamaterial is further reduced. When the diameter lm of the conductive geometric unit is 4 micrometers, the absorption of the superabsorbent metamaterial is the lowest. The operating frequency range shown in Figure 3 is 0.8-2.7 GHz.

[0042] The TM wave is a longitudinal wave in the electromagnetic wave. As shown in FIG. 4, the reflectance in the TM mode decreases as the vertical incidence reflectance of the material increases after the conductive geometric unit is increased, when the diameter lm of the conductive geometric unit 1 is At 3 micron 吋, the reflectivity of the absorbing supermaterial shown in Figure 2 is lower than that of the magnetic electromagnetic absorbing material layer without conductive geometrical elements. When the diameter lm of the conductive geometric unit 1 is 3.5 μm, the reflectance of the absorbing supermaterial is further lowered. When the diameter of the conductive geometric unit lm is 4 μm, the absorption of the superabsorbent material is the lowest. The operating frequency range shown in Figure 4 is 0.8-2.7 GHz. It is worth mentioning that embodiments according to the invention are not limited to a particular operating frequency, but the electromagnetic microstructure can be correspondingly designed according to the set operating frequency and the absorbing material employed.

Embodiment 2

The present embodiment has the same reference numerals and the same reference numerals, and the description of the same technical description is omitted. For the description of the omitted portions, reference may be made to the foregoing embodiments, and the detailed description is not repeated herein.

As shown in FIG. 5, unlike Embodiment 1, the conductive geometric unit 4 has an octagonal shape of a cornice, and a parallel metal strip 40 is disposed at the opening. As shown in FIG. 5, the arrangement rule of the conductive geometric unit 4 is a periodic rule, and the periodic law is periodically arranged in two directions perpendicular to each other in the plane, extending in a square grid form, but the arrangement law is not limited. Therefore, it may be a misaligned arrangement or a disordered arrangement or an uneven arrangement. Conductive Geometry Unit 4 The diameter of the circumscribed circle can be set to 1/20~1/5 of the free space electromagnetic wave length of the working frequency band.

[0046] As shown in FIG. 6, the reflectance in the TE mode decreases after the increase of the conductive geometry unit, and the diameter of the conductive geometric unit 4 is 3 micrometers, as shown in FIG. The reflectivity of the absorbing supermaterial is lower than that of the magnetic electromagnetic absorbing material layer without the conductive geometric unit

. When the diameter lm of the conductive geometric unit 4 is 3.5 μm, the reflectance of the absorbing supermaterial is further lowered. When the diameter of the conductive geometric unit lm is 4 μm, the absorption of the superabsorbent material is the lowest. The operating frequency range shown in Figure 6 is 0.8-2.7 GHz.

[0047] As shown in FIG. 7, the reflectance in the TM mode decreases after the increase in the conductive geometry unit, and the diameter of the conductive geometric unit 4 is 3 micrometers, as shown in FIG. Absorbing metamaterial The reflectivity is lower relative to the reflectivity of the layer of magnetic electromagnetically absorbing material without conductive geometric elements. When the diameter lm of the conductive geometric unit 4 is 3.5 μm, the reflectance of the absorbing wave metamaterial is further lowered. When the diameter lm of the conductive geometric unit 4 is 4 micrometers, the absorption of the superabsorbent metamaterial is the lowest. The operating frequency range shown in Figure 7 is 0.8-2.7 GHz.

Embodiment 3

[0049] The present embodiment uses the same reference numerals and the same elements as the above, and the same reference numerals are used to denote the same or similar elements, and the description of the same technical content is selectively omitted. For the description of the omitted portions, reference may be made to the foregoing embodiments, and the detailed description is not repeated herein.

[0050] As shown in FIG. 8, different from Embodiment 1, the conductive geometric unit 5 has a quadrangular shape with a cornice, and a parallel metal strip 50 is disposed at the cornice, and the center of the edge where the cornice is located is displaced to Inside the quadrilateral. As shown in FIG. 8, the arrangement rule of the conductive geometric unit 5 is a periodic rule, and the periodic law is periodically arranged in two directions perpendicular to each other in the plane, extending in a square grid form, but the arrangement law is not limited Therefore, it may be a misaligned arrangement or a disordered arrangement or an uneven arrangement. Conductive Geometry Unit 5 The diameter of the circumscribed circle can be set to 1/20~1/5 of the free-space electromagnetic wavelength of the working frequency band.

[0051] As shown in FIG. 9, the reflectance in the TE mode decreases as the vertical incidence reflectance of the material increases after the conductive geometric unit is increased, when the diameter lm of the conductive geometric unit 5 is 3 micrometers, as shown in FIG. The reflectivity of the absorbing supermaterial is lower than that of the magnetic electromagnetic absorbing material layer without the conductive geometric unit

. When the diameter lm of the conductive geometric unit 5 is 3.5 μm, the reflectance of the absorbing supermaterial is further lowered. When the diameter of the conductive geometric unit lm is 4 μm, the absorption of the superabsorbent material is the lowest. The operating frequency range shown in Figure 9 is 0.8-2.7 GHz.

As shown in FIG. 10, the reflectance in the TM mode decreases as the vertical incidence reflectance of the material increases after the conductive geometric unit, when the diameter lm of the conductive geometric unit 5 is 3 micrometers, as shown in FIG. The reflectivity of the absorbing supermaterial is lower than that of the magnetic electromagnetic absorbing material layer without the conductive geometric unit. When the diameter lm of the conductive geometric unit 5 is 3.5 μm, the reflectance of the absorbing supermaterial is further lowered. When the diameter lm of the conductive geometric unit 5 is 4 μm, the absorption of the superabsorbent metamaterial is the lowest. The operating frequency range shown in Figure 10 is 0.8-2.7 GHz.

Example 4

[0054] This embodiment uses the component numbers and parts of the foregoing embodiments, wherein the same reference numerals are used. The same or similar elements, and the description of the same technical content is selectively omitted. For the description of the omitted part, reference may be made to the foregoing embodiment, and the detailed description is not repeated herein.

[0055] This embodiment employs Example 3 or a absorbing wave metamaterial similar to that of Embodiment 3. As shown in Figure 11, the reflectivity in the TE mode decreases as the large angle incident reflectance of the material increases after the conductive geometry unit. When using a absorbing supermaterial 带 with a conductive geometry unit 5, the reflectivity of the absorbing supermaterial shown in Figure 8 is lower than that of the magnetic electromagnetic absorbing material layer without the conductive geometric unit, even in At a large angle of incidence of 50 degrees, 60 degrees, and 70 degrees, the reflectance also drops significantly. Although not shown in the figure, the reflectance is also lowered at an incident angle of 85 degrees.

[0056] As shown in FIG. 12, the reflectance in the TM mode decreases the large-angle incident reflectance of the material after the conductive geometry unit is increased, and when the absorbing supermaterial 带 with the conductive geometric unit 5 is used, FIG. 8 The reflectivity of the absorbing wave metamaterial shown is lower than that of the magnetic electromagnetic absorbing material layer without the conductive geometric unit, and the reflectance is significantly reduced even at a large angle of incidence of 50 degrees, 60 degrees, and 70 degrees. Although not shown in the figure, the reflectance is also lowered at an incident angle of 85 degrees.

[0057] In the prior art, in the case of "the electromagnetic wave is more reflective on the surface of the absorbing material, which is not conducive to the absorption of electromagnetic waves, especially under the condition of large angle incidence, the reflection is more serious", the industry usually takes advantage of Layer absorbing materials, or gradient electromagnetic parameters in the absorbing material to achieve better impedance matching and reduce surface reflection, but multi-layer absorbing waves bring about an increase in surface density of the product, requiring more installation space. Increasing the complexity of production preparation and testing, the process complexity of gradient-changing absorbing materials increases, and the difficulty of process control increases, often accompanied by a decline in product consistency.

[0058] In the foregoing embodiment, the annular conductive geometry in the conductive geometric unit is equivalent to the inductance L in the circuit, and the two parallel strip structures are equivalent to the capacitance C in the circuit, which is a combination LC circuit, Figure 1 is equivalent to two inductors and two capacitors in series, by adjusting the size of the conductive geometry unit to change its electromagnetic parameter performance, to achieve the desired effect, that is, the required operating frequency of the absorbing wave metamaterial The electromagnetic wave inside is concentrated and absorbed, which is convenient for absorption by the magnetic electromagnetic absorbing material layer disposed below, and the added metal back plate emits the absorbed electromagnetic wave to the magnetic absorbing material layer for secondary absorption. According to the embodiment of the present invention, the reflection of the absorbing material against the vertical incidence of the electromagnetic wave and the entrance of the large angle 降低 can be reduced, and the working frequency band is changed by changing the topology and arrangement of the electromagnetic metamaterial by the electromagnetic characteristics of the conventional absorbing material. Its own electromagnetic parameters and overall equivalent electromagnetic parameters, thus achieving a drop Low reflectivity effect. Moreover, the multi-layer absorbing material is not required, so that the absorbing effect equivalent to the prior art can be realized under the condition of lighter and thinner, that is, the absorption effect equivalent to the conventional material can be realized under the condition of lower areal density.

[0059] Embodiments of the invention may be, but are not limited to, applied to portions having antenna reflectors and antenna pods. For example, the products that can be used include a plate antenna, a directional base station antenna, a reflector antenna, etc., and applicable systems include mobile communication, wireless coverage, satellite communication, and the like. These applications can lead to an increase in antenna performance, mainly due to the improvement of indicators such as front-to-back ratio and cross-polarization isolation and improvement of electromagnetic compatibility.

Another embodiment of the present invention provides a radome that includes the absorbing wave metamaterial of the previous embodiment. The radome also has the advantages of the previous embodiment, with a low reflectivity at normal incidence and at large angles of incidence.

Another embodiment of the present invention provides an antenna system including the absorbing wave metamaterial in the foregoing embodiment.

The radome also has the advantages of the previous embodiment, with a lower reflectivity at normal incidence and at large angles of incidence.

The present invention is not limited to the present invention, but may be made by those skilled in the art without departing from the spirit and scope of the invention. For example, different topological structures of conductive geometrical units can adjust the electromagnetic parameters of different frequency segments, thereby reducing the reflectivity of the overall absorbing material, and the periodicity of the arrangement of the conductive geometrical elements is expressed as a certain angle in the plane. The two directions are periodically arranged and extended in the form of a triangular mesh; for example, a protective material may be disposed on the conductive geometric unit; the conductive geometric structure includes but is not limited to a metal microstructure or a non-metal conductive micro Structure, which can be circular, elliptical, triangular or polygonal or other shapes. Therefore, any modifications, equivalent changes, and modifications of the above embodiments may be made without departing from the spirit and scope of the invention.

Claims

Claim

[Attachment 1] The absorbing wave metamaterial, comprising: a magnetic electromagnetic absorbing material layer and a conductive geometric layer combined with the magnetic electromagnetic absorbing material layer; the conductive geometric layer is sequentially arranged The conductive geometrical unit is composed of a non-closed annular conductive geometric structure, and the annular conductive geometric structure is provided with two strip structures which are relatively parallel.

[Claim 2] The wave absorbing metamaterial according to claim 1, wherein the annular conductive geometric structure is provided with one or more of the openings.

[Claim 3] The wave absorbing metamaterial according to claim 1, wherein the annular conductive geometric structure is circular, elliptical, triangular or polygonal.

[Claim 4] The absorbing wave metamaterial according to claim 1, wherein the magnetic electromagnetic absorbing material layer has a dielectric constant of 5 to 30 and a magnetic permeability of 1 to 7.

[Claim 5] The wave absorbing metamaterial of claim 1, wherein the conductive geometric units are arranged in a periodic array.

The absorbing wave metamaterial according to claim 1, wherein the surface of the magnetic electromagnetic absorbing material layer is further provided with a metal backing plate.

The absorbing wave metamaterial according to claim 6, wherein the magnetic electromagnetic absorbing material layer is a absorbing wave patch material.

The absorbing wave metamaterial according to claim 1, wherein the conductive geometric unit is attached to the magnetic electromagnetic absorbing material layer or embedded in the magnetic electromagnetic absorbing material layer.

The absorbing wave metamaterial according to claim 1, wherein the magnetic electromagnetic absorbing material layer comprises a substrate and an absorbent bonded to the substrate.

[Claim 10] The absorbing wave metamaterial according to claim 1, wherein the conductive geometric unit has a shape of a circumscribed circle, and the diameter of the circumscribed circle is 1/1 of a free-space electromagnetic wavelength of an operating band 20-1/5.

[Claim 11] The absorbing wave metamaterial according to claim 1, wherein the absorbing wave metamaterial has an operating frequency in a frequency range of 0.8 to 2.7 GHz, and the thickness of the conductive geometric unit is greater than The skin depth of the conductive geometric unit of the working frequency segment.

[Claim 12] The absorbing wave metamaterial according to claim 6, wherein the absorbing wave metamaterial has an operating frequency in a frequency range of 0.8-2.7 GHz, and the thickness of the metal backing plate is greater than the corresponding The skin depth of the metal backing plate of the working frequency segment.

The absorbing wave metamaterial according to claim 1, wherein the annular conductive geometric structure and the strip structure have a line width of W, 0.1 mm ≤ W ≤ 1 mm.

The absorbing wave metamaterial according to claim 1, wherein the annular conductive geometric structure and the strip structure have a thickness of H, 0.005 mm ≤ H ≤ 0.05 mm.

[Claim 15] A radome, comprising the absorbing wave metamaterial according to any one of claims 1 to 14.

[Claim 16] An antenna system, comprising the absorbing wave metamaterial of any one of claims 1 to 14.