An electromagnetic wave absorbing metamaterial

Abstract

The present invention discloses a wave-absorbing metamaterial, comprising: a plurality of metamaterial units arranged periodically, wherein each of the metamaterial units includes: a first loop disposed in a first plane; and a second loop disposed in a second plane, the first plane being perpendicular to the second plane so that the first loop is orthogonal to the second loop. The above technical solution of the present invention can achieve wave absorption within a large angular range while ensuring broadband wave absorption.

Description

Technical Field

[0001] The present invention relates to the technical field of metamaterials, and more specifically, to a wave-absorbing metamaterial. Background Art

[0002] With the continuous development of modern communication technologies, the electromagnetic spectrum resources are becoming increasingly tense. At the same time, the rampant electromagnetic waves have also formed the fourth major public hazard endangering human survival, namely electromagnetic pollution. To achieve electromagnetic compatibility and control electromagnetic pollution, using wave-absorbing materials is an effective means. Using wave-absorbing materials to absorb electromagnetic waves in specific frequency bands can not only avoid the interference of external electromagnetic waves on the normal operation of radio equipment, but also reduce the electromagnetic waves existing in free space.

[0003] Currently, a common broadband wave-absorbing material structure is achieved by cascading and superposing multiple two-dimensional structures. This structure can achieve broadband wave absorption, but due to its complex structure and the difficulty in impedance matching between multiple layers, once the incident angle changes, its wave-absorbing effect will also change significantly. In addition, due to the superposition of multiple two-dimensional structures, the wave-transmitting ability of this structure is poor, and high wave transmission can only be achieved within an extremely narrow frequency band. Summary of the Invention

[0004] In view of the above problems in the related art, the present invention provides a wave-absorbing metamaterial that can achieve wave absorption within a large angular range while ensuring broadband wave absorption.

[0005] The technical solution of the present invention is implemented as follows:

[0006] According to one aspect of the present invention, there is provided a wave-absorbing metamaterial, including a plurality of metamaterial units arranged in a periodic pattern, wherein each metamaterial unit includes:

[0007] A first loop disposed in a first plane;

[0008] A second loop disposed in a second plane, the first plane being perpendicular to the second plane such that the first loop is orthogonal to the second loop.

[0009] According to an embodiment of the present invention, each metamaterial unit further includes a first dielectric plate and a second dielectric plate that are perpendicular to each other, wherein the first loop and the second loop are respectively disposed on the first dielectric plate and the second dielectric plate.

[0010] According to an embodiment of the present invention, each of the first loop and the second loop includes: two metal half-rings spaced apart from each other and having opposite openings; two resistors, with each end of each resistor connected to two opposite ends of the two metal half-rings on the same side.

[0011] According to an embodiment of the present invention, a metal extension portion is further provided between both ends of each resistor and an end portion of the corresponding metal half-ring.

[0012] According to an embodiment of the present invention, one resistor in the first loop is located between two opposite metal half-rings in the second loop, and the other resistor in the first loop is located outside the two opposite metal half-rings in the second loop.

[0013] According to an embodiment of the present invention, in each of the first loop and the second loop, the resistance values of the two resistors are different.

[0014] According to an embodiment of the present invention, the sizes of the two metal half-rings in the first loop are the same as those of the two metal half-rings in the second loop.

[0015] According to an embodiment of the present invention, an electrolyte is filled between an adjacent first dielectric plate and an adjacent second dielectric plate.

[0016] According to an embodiment of the present invention, the absorbing metamaterial further includes: a metal backplane, perpendicular to the first plane and perpendicular to the second plane; wherein, a plurality of metamaterial units are arranged periodically on one side of the metal backplane.

[0017] According to an embodiment of the present invention, the absorbing metamaterial further includes: a skin, and a plurality of metamaterial units are arranged periodically on one side of the skin.

[0018] The above technical solution of the present invention is based on a three-dimensional structure of metamaterials, with a simple and clear structure, and impedance matching is easy to achieve; moreover, by reasonably adjusting the parameters and positions of the first loop and the second loop, it is possible to achieve wave absorption in a large angle range on the premise of ensuring broadband wave absorption. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 is a schematic diagram of an orthogonal loop of an absorbing metamaterial according to an embodiment of the present invention;

[0021] Figure 2 is a schematic diagram of an absorbing metamaterial according to an embodiment of the present invention;

[0022] Figure 3 is a schematic diagram of a loop of an absorbing metamaterial according to an embodiment of the present invention;

[0023] Figure 4A is a front view schematic diagram of a dielectric plate of an electromagnetic wave absorbing metamaterial according to an embodiment of the present invention;

[0024] Figure 4B is a side view schematic diagram of a dielectric plate of an electromagnetic wave absorbing metamaterial according to an embodiment of the present invention;

[0025] Figure 5 is a schematic diagram of a parallel polarization absorption curve of an electromagnetic wave absorbing metamaterial according to a specific embodiment of the present invention;

[0026] Figure 6 is a schematic diagram of a parallel polarization reflection curve of an electromagnetic wave absorbing metamaterial according to a specific embodiment of the present invention;

[0027] Figure 7 is a schematic diagram of a vertical polarization absorption curve of an electromagnetic wave absorbing metamaterial according to a specific embodiment of the present invention;

[0028] Figure 8 is a schematic diagram of a vertical polarization reflection curve of an electromagnetic wave absorbing metamaterial according to a specific embodiment of the present invention. Detailed Embodiments

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0030] It should be understood that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present application. In addition, features defined with "first", "second" may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise stated, the meaning of "a plurality" is two or more.

[0031] Combined with Figure 1 and Figure 2 as shown, the present invention provides an electromagnetic wave absorbing metamaterial, which includes a plurality of metamaterial units 100 arranged in a periodic manner. Among them, the metamaterial unit 100 includes: a first loop 10 disposed in a first plane, and a second loop 20 disposed in a second plane. Wherein, the first plane is perpendicular to the second plane so that the first loop 10 and the second loop 20 are orthogonal to each other. It should be understood that in Figure 1 , the first plane is the XY plane and the second plane is the YZ plane. In addition, Figure 1 and Figure 2Only one metamaterial unit 100 is shown herein, which does not mean that the wave-absorbing metamaterial of the present invention only includes one metamaterial unit. The specific number of metamaterial units can be determined according to specific application scenarios.

[0032] Based on the above technical solution of the present invention, with the three-dimensional structure of the metamaterial as the basis, the structure is simple and clear, and impedance matching is easy to achieve. Moreover, by reasonably adjusting the parameters and positions of the first loop 10 and the second loop 20, it is possible to achieve wave absorption within a large angular range while ensuring broadband wave absorption.

[0033] Reference Figure 1 As shown, the first loop 10 includes: two metal half-rings 12, 14 and two resistors 16, 18. The two metal half-rings 12, 14 are spaced apart from each other and have their openings facing each other. The resistors 16, 18 are both connected to the two metal half-rings 12, 14 with their openings facing each other. Specifically, the two ends of the resistor 16 are respectively connected to two opposite ends of the two metal half-rings 12, 14 on the same side, and the two ends of the resistor 18 are respectively connected to two opposite ends of the two metal half-rings 12, 14 on the other side. The two metal half-rings 12, 14 together form the shape of a running track of a sports field, that is, the ends on the same side of two parallel lines are each connected to a semi-circle, and each metal half-ring (12 or 14) includes a semi-circle and half of two parallel lines. Similarly, the second loop 20 includes: two metal half-rings 22, 24 and two resistors 26, 28. The two metal half-rings 22, 24 are spaced apart from each other and have their openings facing each other. The resistors 26, 28 are both connected to the two metal half-rings 22, 24 with their openings facing each other. Specifically, the two ends of the resistor 26 are respectively connected to two opposite ends of the two metal half-rings 22, 24 on the same side, and the two ends of the resistor 28 are respectively connected to two opposite ends of the two metal half-rings 22, 24 on the other side. The two metal half-rings 22, 24 together also form the shape of a running track of a sports field, that is, the ends on the same side of two parallel lines are each connected to a semi-circle, and each metal half-ring (22 or 24) includes a semi-circle and half of two parallel lines. In this way, by using two resistors to connect two metal half-rings in the same plane in series, the first loop and the second loop are respectively formed. Moreover, the mutually orthogonal first loop 10 and second loop 20 enable the wave-absorbing metamaterial of the present invention to have good wave-absorbing performance under dual polarization. In addition, due to the use of such a three-dimensional structure, the metal duty cycle in the incident direction Din of the electromagnetic wave (such as Figure 2 ) is low, so it is easier to achieve impedance matching.

[0034] Continue to refer to Figure 1As shown, in the first loop 10, metal extensions 15 are also provided between both ends of the resistors 16 and 18 and the ends of the corresponding metal half-rings 12 and 14 to form two sets of parallel lines. In the second loop 20, metal extensions 25 are also provided between both ends of the resistors 26 and 28 and the ends of the corresponding metal half-rings 22 and 24 to form two sets of parallel lines.

[0035] Among them, one resistor 16 in the first loop 10 is located between two opposite metal half-rings 22 and 24 in the second loop 20, and the other resistor 18 in the first loop 10 is located outside two opposite metal half-rings 22 and 24 in the second loop 20. That is, the resistor 16 in the first loop 10 is located inside the second loop 20 formed by the series connection of the metal half-rings 22 and 24 and the two resistors 26 and 28, and the resistor 18 in the first loop 10 is located outside the second loop 20. Such a design is also convenient for impedance matching.

[0036] In this embodiment, the sizes of the two metal half-rings 12 and 14 in the first loop 10 are the same as the sizes of the two metal half-rings 22 and 24 in the second loop 20.

[0037] In one embodiment, among the two resistors 16 and 18 in the first loop 10, the resistance values can be different. Among the two resistors 26 and 28 in the second loop 20, the resistance values can be different. In one embodiment, among the two resistors 16 and 18 in the first loop 10, the resistance values can be the same. In one embodiment, among the two resistors 26 and 28 in the second loop 20, the resistance values can be the same.

[0038] In another embodiment, one resistor 16 in the first loop 10 is located between two opposite metal half-rings 22 and 24 in the second loop 20, and the other resistor 18 in the first loop 10 is located between two opposite metal half-rings 22 and 24 in the second loop 20. That is, the resistor 16 in the first loop 10 is located inside the second loop 20 formed by the series connection of the metal half-rings 22 and 24 and the two resistors 26 and 28, and the resistor 18 in the first loop 10 is also located inside the second loop 20. Moreover, the first loop 10 coincides with the second loop 20 after rotating 90 degrees counterclockwise around the orthogonal line where the first loop 10 and the second loop 20 are orthogonal to each other. Such a design can also achieve impedance matching.

[0039] Reference Figure 2As shown, each metamaterial unit 100 further includes a first dielectric plate 11 and a second dielectric plate 21 that are perpendicular to each other. Among them, the first loop 10 and the second loop 20 are respectively disposed on the first dielectric plate 11 and the second dielectric plate 21. By adjusting the radii of the metal half-rings 12, 14, 22, 24 in the first and second loops 10, 20, and the thicknesses of the first and second dielectric plates 11, 21 in the incident direction Din (i.e., Figure 4B the thickness D2 in

[0040] ), the absorption frequency band can be adjusted, which enables the wave-absorbing metamaterial of the present invention not to correspond to a single frequency band, but to adjust the absorption frequency band through parameter settings.

[0041] Continuing to refer to Figure 2 As shown, the wave-absorbing metamaterial of the present invention further includes a metal backplane 200, which is perpendicular to the above-mentioned first plane and perpendicular to the second plane. That is to say, the metal backplane 200 is perpendicular to the first dielectric plate 11 and the second dielectric plate 21. Among them, a plurality of metamaterial units 100 are arranged periodically on one side of the metal backplane 200. The metal backplane 200 can be any one of metals such as copper, silver, and gold.

[0042] In some embodiments, the wave-absorbing metamaterial of the present invention may further include a skin (not shown), and a plurality of metamaterial units 100 are arranged periodically on one side of the skin. For example, the skin can be disposed opposite to the metal backplane 200, and a plurality of metamaterial units 100 are arranged periodically on the side of the skin adjacent to the metal backplane 200, that is, a plurality of metamaterial units 100 are located between the skin and the metal backplane 200. By adding a skin on one side of the periodically arranged plurality of metamaterial units 100 for protection, it is possible to ensure a high wave transmission rate at low frequencies while absorbing waves in a wide frequency band.

[0043] Combining again with Figure 1 and Figure 2 As shown, in one embodiment, the metal half-ring can be a copper ring with a thickness of 20 microns, and the dielectric constants of the first and second dielectric plates are both 3.1, and the loss tangent is 0.6%. In one embodiment, the metal half-ring can be any one of metals such as gold and silver.

[0044] Combining with Figure 3 , Figure 4A and Figure 4BAs shown, in a specific embodiment, the sizes of the metal half-rings in the first and second circuits 10 and 20 are the same. Specifically, the inner diameter Φ1 of the metal half-ring is 2.6 mm, the width D1 of the metal half-ring is 0.6 mm, the distance L1 between two metal half-rings and the metal extension part in the same plane (i.e., in the same circuit) is 2 mm, and the length L2 of the metal extension part is 0.9 mm. The lengths of the first dielectric plate 11 and the second dielectric plate 21 are both L3 = 8 mm, the thicknesses are both D2 = 0.8 mm, and the widths are both H1 = 7 mm. The resistance value R1 of one resistor (such as resistors 16 and 26) in the first and second circuits 10 and 20 is 500 Ω, and the resistance value R2 of the other resistor (such as resistors 18 and 28) is 150 Ω.

[0045] Figures 5 to 8 shows Figure 3 , Figure 4A and Figure 4B the simulation results of the embodiment shown. As can be seen from the simulation results, referring to Figure 5 and Figure 6 shown, in the TE polarization, in the range of 0 - 60°, from the X-band (8 GHz - 12 GHz) to the Ku-band (12 GHz - 18 GHz), the absorption rate basically reaches more than 70%, and in the Ku-band, it reaches more than 90%. Referring to Figure 7 and Figure 8 shown, in the TM polarization, the absorption rate in the X - Ku band basically reaches more than 70% in the range of 0 - 40°, and in the Ku-band, in the range of 0 - 60°, the absorption rate basically reaches more than 70%. It should be noted that this embodiment is only an example. By adjusting parameters such as the size of the metal half-ring, the thickness and width of the dielectric plate, and the resistance value of the resistor, the wave absorption range can be freely adjusted, and such a wave absorption range can cover the currently commonly used electromagnetic wave frequency bands.

[0046] The wave-absorbing metamaterial of the present invention can be applied to an antenna radome, which can ensure that the performance of the antenna protected by the antenna radome is basically not affected within the working frequency band, while electromagnetic waves outside the band cannot enter the antenna radome. The wave-absorbing metamaterial of the present invention can also be applied to the communication field, which can provide a new way to realize functions such as using independent channels for each sub-antenna of an antenna array.

[0047] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An electromagnetic wave absorbing metamaterial, characterized in that, Comprising a plurality of metamaterial units arranged in a periodic pattern, wherein each of the metamaterial units includes: A first loop disposed in a first plane; A second loop disposed in a second plane, the first plane being perpendicular to the second plane such that the first loop is orthogonal to the second loop; Wherein each of the first loop and the second loop includes: Two metal half-rings spaced apart from each other and having opposite openings; Two resistors, with each end of each resistor connected to two opposite ends of the two metal half-rings on the same side; Wherein one resistor in the first loop is located between two opposite metal half-rings in the second loop, and the other resistor in the first loop is located outside two opposite metal half-rings in the second loop. Moreover, metal extension parts are provided between the two ends of each resistor and the ends of the corresponding metal half-ring, and the metal extension parts respectively connected to the two ends of the metal half-ring are parallel to each other.

2. The microwave absorbing metamaterial according to claim 1, wherein The metamaterial unit further includes a first dielectric plate and a second dielectric plate perpendicular to each other, wherein the first loop and the second loop are respectively disposed on the first dielectric plate and the second dielectric plate.

3. The microwave absorbing metamaterial according to claim 1, wherein In each of the first loop and the second loop, the resistance values of the two resistors are different.

4. The microwave absorbing metamaterial according to claim 1, wherein The sizes of the two metal half-rings of the first loop are the same as those of the two metal half-rings of the second loop.

5. The microwave absorbing metamaterial according to claim 2, wherein An electrolyte is filled between adjacent first dielectric plates and adjacent second dielectric plates.

6. The absorbing metamaterial according to claim 1, wherein The absorbing metamaterial further includes: A metal backplane perpendicular to the first plane and perpendicular to the second plane; Wherein the plurality of metamaterial units are arranged in a periodic pattern on one side of the metal backplane.

7. The microwave absorbing metamaterial according to claim 1, wherein The absorbing metamaterial further includes: A skin, and the plurality of metamaterial units are arranged in a periodic pattern on one side of the skin.

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