Wave absorbing structure, device and manufacturing method

Abstract

The present invention discloses an absorbing structure, device, and manufacturing method. The absorbing structure comprises: a magnetic medium layer; a first substrate layer disposed at one end of the magnetic medium layer and having a through hole; and a coil wound around the first substrate layer and the magnetic medium layer, which regulates the applied magnetic field of the magnetic medium layer according to an external voltage. The present invention adjusts the conduction current of the coil by applying an external voltage to the coil, thereby regulating the magnetic field of the magnetic medium layer. This allows the magnetic medium layer to absorb electromagnetic waves of different frequency bands. This allows absorption of different frequency bands to be achieved without requiring replacement of the absorbing material, thus saving costs.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic wave technology, and in particular to a wave absorbing structure, a device and a manufacturing method. Background Art

[0002] Absorbing materials play a vital role in daily life, scientific research, national defense, and military applications. For example, in everyday life, they absorb electromagnetic pollution from the environment. In scientific research, they protect precision instruments from radiation and are used in anechoic chambers to ensure the accuracy of test results. In the military, absorbing materials absorb and dissipate incident electromagnetic energy to achieve stealth technology, reducing the chance of enemy radar detection.

[0003] However, currently, the main absorbing materials used are carbon-based absorbing materials, iron-based absorbing materials, ceramic absorbing materials, etc., and solid absorbing materials can only absorb electromagnetic waves of a fixed frequency and cannot absorb electromagnetic waves of multiple frequency bands. In order to absorb electromagnetic waves of different frequency bands, different absorbing materials need to be replaced, thereby increasing the absorbing cost. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes an absorbing structure that can adjust the frequency band of electromagnetic waves absorbed, eliminating the need to replace absorbing materials and saving costs.

[0005] The present invention also provides a wave absorbing device.

[0006] The invention also provides a method for manufacturing the wave absorbing structure.

[0007] In a first aspect, an embodiment of the present invention provides an absorbing structure, comprising:

[0008] a magnetic medium layer;

[0009] A first substrate layer is provided at one end of the magnetic medium layer and has a through hole;

[0010] The coil is wound around the first substrate layer and the magnetic medium layer and adjusts the external magnetic field of the magnetic medium layer according to an external voltage.

[0011] The absorbing structure of the embodiment of the present invention has at least the following beneficial effects: an external voltage is connected to the coil to adjust the conduction current of the coil, thereby adjusting the magnetic field of the magnetic medium layer to enable the magnetic medium layer to absorb electromagnetic waves of different frequency bands. The absorbing material needs to be replaced to achieve the absorption of electromagnetic waves of different frequency bands, thereby saving costs.

[0012] According to some other embodiments of the present invention, the wave absorbing structure further includes:

[0013] The second substrate layer is arranged at an end of the magnetic medium layer away from the first substrate layer.

[0014] According to some other embodiments of the wave absorbing structure of the present invention, the through hole is in the shape of a Jerusalem cross.

[0015] According to some other embodiments of the wave absorbing structure of the present invention, the thickness of the first substrate layer is 1-2 mm.

[0016] According to some other embodiments of the wave absorbing structure of the present invention, the thickness of the magnetic medium layer is 0.5-2 mm.

[0017] According to some other embodiments of the wave absorbing structure of the present invention, the magnetic medium layer is yttrium iron garnet.

[0018] According to some other embodiments of the wave absorbing structure of the present invention, the external voltage and the number of coils are adjusted so that the external magnetic field of the magnetic medium layer is 0-6000 Oe.

[0019] According to some other embodiments of the wave absorbing structure of the present invention, the second substrate layer is a metal plate.

[0020] In a second aspect, an embodiment of the present invention provides an absorbing device, comprising:

[0021] Several wave absorbing structures as described in the first aspect;

[0022] The plurality of wave absorbing structures are arranged in an array.

[0023] The wave absorbing device of the embodiment of the present invention has at least the following beneficial effects: a plurality of wave absorbing structures are arranged in an array and can be set according to different space sizes, thereby facilitating use in spaces of different sizes.

[0024] In a third aspect, an embodiment of the present invention provides a method for manufacturing an absorbing structure, which is applied to the manufacture of the absorbing structure, comprising:

[0025] determining a first thickness, a through-hole structure, a magnetic permeability, and a second thickness according to an initial resonant frequency;

[0026] manufacturing a first substrate layer according to the first thickness and the through-hole structure;

[0027] manufacturing a magnetic medium layer according to the magnetic permeability and the second thickness;

[0028] combining the first substrate layer and the magnetic medium layer to form a combined layer;

[0029] A coil is wound around the combined layers.

[0030] The method for manufacturing an absorbing structure according to an embodiment of the present invention has at least the following beneficial effects: the specific size of the absorbing structure is determined by the initial resonant frequency, so that the manufactured absorbing structure is adjusted to a required resonant frequency value.

[0031] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present application. The purposes and other advantages of the present application can be realized and obtained through the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 1 is a schematic structural diagram of a specific embodiment of the wave absorbing structure in an embodiment of the present invention;

[0033] Figure 2 1 is a schematic structural diagram of a specific embodiment of the wave absorbing structure in an embodiment of the present invention;

[0034] Figure 3 It is a flow chart of a specific embodiment of the method for manufacturing an absorbing structure in an embodiment of the present invention.

[0035] Reference numerals: 100 , first substrate layer; 110 , through hole; 111 , first connection hole; 112 , second connection hole; 200 , magnetic medium layer; 300 , second substrate layer; 400 , coil. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the concept and technical effects of the present invention in conjunction with the embodiments to fully understand the purpose, features and effects of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0037] In the description of the present invention, if any directional description is involved, such as "upper," "lower," "front," "back," "left," "right," etc., indicating directions or positional relationships, these are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed or operate in a specific orientation. Therefore, they should not be understood as limiting the present invention. If a feature is referred to as being "disposed," "fixed," "connected," or "mounted" on another feature, it may be directly disposed, fixed, or connected to the other feature, or indirectly disposed, fixed, connected, or mounted on the other feature.

[0038] In the description of the embodiments of the present invention, if the word "several" is mentioned, it means more than one; if the word "plurality" is mentioned, it means more than two; if the word "greater than," "less than," or "exceeds," it should be understood as excluding the number itself; if the word "above," "below," or "within" is mentioned, it should be understood as including the number itself. If the word "first" or "second" is mentioned, it should be understood as distinguishing technical features and should not be understood as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0039] Reference below Figure 1 and Figure 2 A wave absorbing structure according to an embodiment of the present invention is described.

[0040] like Figure 1 and Figure 2 As shown, the wave absorbing structure according to the embodiment of the present invention includes: a first substrate layer 100, a magnetic medium layer 200 and a coil 400;

[0041] A through hole 110 is opened on the first substrate layer 100 , the magnetic medium layer 200 is located at the bottom of the first substrate layer 100 , and the coil 400 is wound around the first substrate layer 100 and the magnetic medium layer 200 .

[0042] The first substrate layer 100 and the magnetic medium layer 200 are layered together, and the first substrate layer 100 is provided with a through hole 110. When electromagnetic waves are incident on the first substrate layer 100, they enter the magnetic medium layer 200 through the through hole 110. When an external voltage is applied to the coil 400 to adjust the current flowing through the coil 400, the magnetic field on the magnetic medium layer 200 changes, generating a resonant frequency that interacts with the electromagnetic waves, thereby absorbing the waves. By applying different voltage values ​​to the external voltage applied to the coil 400, the current flowing through the coil 400 changes, and the magnitude of the magnetic field generated by the coil 400 is adjustable, the magnetic permeability of the magnetic medium layer 200 is adjustable, and thus the frequency band of electromagnetic waves absorbed by the magnetic medium layer 200 is adjustable. By applying different voltage values ​​to the external voltage, different frequency bands of electromagnetic waves can be absorbed, making absorption of different frequency bands simple, eliminating the need to replace absorbing materials and saving absorption costs.

[0043] Specifically, the first substrate layer 100 is a copper plate, which can absorb part of the electromagnetic waves and block part of the electromagnetic waves. The remaining electromagnetic waves are then coupled through the magnetic medium layer 200, and the coupling process will produce hysteresis, so that the electromagnetic waves can be fully absorbed to improve the absorption of electromagnetic waves.

[0044] In some embodiments, the wave absorbing structure further includes a second substrate layer 300 . The second substrate layer 300 is disposed on an end of the magnetic medium layer 200 away from the first substrate layer 100 .

[0045] When part of the electromagnetic wave passes through the second substrate layer 300 after being transmitted from the magnetic medium layer 200 , the second substrate layer 300 blocks the transmission of the electromagnetic wave, thereby improving the effect of the electromagnetic wave frequency.

[0046] In some embodiments, the through hole 110 includes a first connection hole 111 and a second connection hole 112 . The second connection hole 112 is disposed at an end of the first connection hole 111 , and the second connection hole 112 is connected to the first connection hole 111 .

[0047] Specifically, the first connection hole 111 is in a cross shape, the second connection hole 112 is in a bar shape, and four second connection holes 112 are provided. The four second connection holes 112 are respectively located at four ends of the first connection hole 111 .

[0048] The electromagnetic waves can be injected into the magnetic medium layer 200 through the first connection hole 111 and the second connection hole 112 . The magnetic medium layer 200 and the electromagnetic waves interact with each other to eliminate redundant electromagnetic waves.

[0049] In some embodiments, the shape formed by the combination of the first connection hole 111 and the second connection hole 112 is a Jerusalem cross shape.

[0050] The through hole 110 is formed by laser processing, and the through hole 110 in the shape of a Jerusalem cross is provided so that electromagnetic waves can be better transmitted through the first substrate layer 100 to the magnetic medium layer 200 for reaction.

[0051] In one embodiment, by changing the conduction current of coil 400 through an external power source, the magnetic permeability of magnetic dielectric layer 200 is altered, thereby changing the resonant frequency of the absorbing structure, thereby adjusting the electromagnetic wave absorption frequency band. Therefore, the resonant frequency of the absorbing structure can be designed according to actual needs. Furthermore, the absorbing structure is designed based on the slow electromagnetic wave effect, which prolongs the interaction between the battery wave and magnetic dielectric layer 200, thereby improving the absorption efficiency.

[0052] Among them, since the absorbing structure is designed based on the slow electromagnetic wave effect, when the electromagnetic wave is incident, the electromagnetic wave will pass through the first substrate layer 100, and then the electromagnetic wave will be incident on the magnetic medium layer 200 through the through hole 110, then the electromagnetic wave and the magnetic medium layer 200 will be coupled, resulting in a certain hysteresis time ΔT s. Since the principle of the magnetic medium layer 200 generating slow waves is similar to using slow light to compress light energy, in turn, the magnetic medium layer 200 compresses energy to slow down the propagation of electromagnetic waves. The slow wave principle is different from using high-refractive optical media to reduce the speed of light. The slow electromagnetic wave effect uses metamaterials to capture electromagnetic waves, so that the interaction time between the electromagnetic waves and the magnetic medium layer 200 is prolonged. Since the mutual time between the electromagnetic waves and the magnetic medium layer 200 is prolonged, the electromagnetic waves can be fully absorbed. And the hysteresis time ΔT of the magnetic medium layer 200 to the electromagnetic waves is in the nanosecond order, consisting of two parts, which can be expressed as:

[0053]

[0054] Wherein, h1 is the thickness of the first substrate layer 100, v z is the speed of the electromagnetic wave in the direction perpendicular to the magnetic medium layer 200 .

[0055] In some embodiments, such as the present embodiment, the absorbing structure can create a hysteresis time of 0.3-0.4 nanoseconds. The specific length of this time is related to the thickness of the first substrate layer 100 and the thickness of the magnetic medium layer 200. Although the hysteresis time allows the magnetic medium layer 200 to fully absorb electromagnetic waves, a longer hysteresis time does not necessarily mean better absorption performance. Instead, they affect each other. Therefore, during preparation, it is necessary to select a reasonable thickness for the first substrate layer 100 and the magnetic medium layer 200.

[0056] Therefore, in this embodiment, the thickness of the first substrate layer 100 is 1-2 mm. By setting the first substrate layer 100 with a thickness of 1-2 mm, on the one hand, the processing of the first substrate layer 100 is facilitated, and on the other hand, the size of the entire absorbing structure is reduced, thereby saving space for the absorbing structure.

[0057] In some embodiments, the thickness of the magnetic medium layer 200 is 0.5-2 mm. Since the wave absorbing structure requires a thinner thickness, the thickness of the magnetic medium layer 200 is set to 0.5-2 mm. On the one hand, this makes the entire magnetic field controllable structure thinner, and on the other hand, the space occupied by the wave absorbing structure is small.

[0058] The magnetic medium layer 200 is made of yttrium iron garnet, which is a synthetic iron oxide crystal with multiple magnetic properties and is commonly used to adjust lasers. Therefore, using yttrium iron garnet as the magnetic medium layer 200 facilitates magnetic permeability adjustment.

[0059] In some embodiments, the external magnetic field applied to the magnetic medium layer 200 is adjusted to a value between 0 and 6000 Oe by adjusting the external voltage and the number of coils 400. Thus, the magnetic field can be adjusted by adjusting the external voltage and the number of coils 400, and the magnetic field range is between 0 and 6000 Oe, achieving magnetic field controllability of the absorbing structure.

[0060] In some embodiments, the interaction between electromagnetic waves and the magnetic medium layer 200 can be divided into reflection, transmission, and absorption. When an electromagnetic wave is incident on the magnetic medium layer 200, part of the energy is reflected, another part of the energy enters the magnetic medium layer 200 and is absorbed, and another part of the energy is transmitted through the magnetic medium layer 200. Let R(ω) be the reflectivity, T(ω) be the transmittance, and A(ω) be the absorptivity. The relationship between the three can be derived from the law of conservation of energy:

[0061] R(ω)+T(ω)+A(ω)=1 (2)

[0062] In order for the magnetic medium layer 200 to absorb incident electromagnetic waves to the maximum extent, the impedance of the free space where the incident waves are located must be matched with the magnetic medium layer 200 , and the electromagnetic waves must be lost as much as possible by various loss mechanisms when passing through the magnetic medium layer 200 .

[0063] The second substrate layer 300 is a metal plate, which can prevent electromagnetic waves passing through the magnetic medium layer 200 from being transmitted out, thereby further improving the electromagnetic wave absorption performance.

[0064] In some embodiments, the dimensions of the absorbing structure are determined based on the initial resonant frequency. Therefore, in this embodiment, the absorbing structure is configured to have a length and width of 10 mm × 10 mm, a diameter of 1 mm for the through hole 110, a length and width of 6.5 mm for the first connection hole 111, a length of 5 mm for the second connection hole 112, a thickness of 1 mm for the first substrate layer 100, and a thickness of 1 mm for the magnetic medium layer 200. This absorbing structure can more efficiently absorb electromagnetic waves.

[0065] Reference below Figure 1 and Figure 2 The wave absorbing structure according to an embodiment of the present invention will be described in detail with reference to a specific embodiment. It should be understood that the following description is merely an illustrative description and does not specifically limit the invention.

[0066] When electromagnetic waves are incident on the first substrate layer 100, since the first substrate layer 100 is a copper plate with a Jerusalem cross-shaped through-hole 110 formed therein, the electromagnetic waves are partially absorbed by the copper plate, while the remaining electromagnetic waves are incident on the magnetic medium layer 200 through the through-hole 110. The external voltage is then adjusted, and a current is applied to the coil 400. This current generates a magnetic field, which changes the magnetic permeability of the magnetic medium layer 200, thereby regulating the electromagnetic wave absorption frequency band. Since the unabsorbed electromagnetic waves are reflected and transmitted through the magnetic medium layer 200, a metal plate is provided at the end of the magnetic medium layer 200 away from the first substrate layer 100. Therefore, the transmitted electromagnetic waves are blocked by the metal plate, thereby achieving a more effective electromagnetic shielding effect.

[0067] In a second aspect, an embodiment of the present invention discloses an absorbing device, comprising:

[0068] The plurality of absorbing structures as in the first aspect are arranged in an array, so as to adapt to spaces of different sizes.

[0069] The specific structure of the wave absorbing structure refers to the wave absorbing structure of the first aspect and will not be described in detail here.

[0070] Thirdly, refer to Figure 3 The embodiment of the present invention discloses a method for manufacturing an absorbing structure, which is applied to the manufacture of the absorbing structure, and includes:

[0071] S100, determining a first thickness, a through-hole structure, a magnetic permeability, and a second thickness according to an initial resonant frequency;

[0072] The initial resonant frequency is determined according to the frequency of electromagnetic waves that need to be absorbed during actual use. Therefore, different initial resonant frequencies need to be set to absorb electromagnetic waves within different frequency bands.

[0073] S200, manufacturing a first substrate layer according to a first thickness and a through-hole structure;

[0074] Since the thickness of the through-hole and the first substrate layer has a regular effect on the frequency of wave absorption, for example, increasing the size of the through-hole will shift the resonant frequency to a lower frequency, the first substrate layer is determined by calculating the first thickness and the through-hole structure to achieve the desired resonant frequency.

[0075] S300, manufacturing a magnetic medium layer according to the magnetic permeability and the second thickness;

[0076] Among them, the magnetic permeability and thickness of the magnetic medium layer have a regular effect on the frequency of wave absorption, but the effect is smaller than that of the first substrate layer. Therefore, the magnetic medium layer is determined by calculating the magnetic permeability and the second thickness, so that the resonant frequency can be fine-tuned to the required value.

[0077] S400, combining the first substrate layer and the magnetic medium layer to form a combined layer;

[0078] S500 , winding a coil around the combined layer.

[0079] In some embodiments, a method for manufacturing an absorbing structure further includes:

[0080] S600 , installing a second substrate layer on an end of the magnetic medium layer away from the first substrate layer.

[0081] By winding a coil on the combined layer so as to input different voltage values ​​into the coil, the magnetic field of the magnetic medium layer can be adjusted, thereby adjusting the frequency of electromagnetic waves absorbed by the magnetic medium layer.

[0082] In some embodiments, when the voltage applied to the coil changes, the applied magnetic field of the magnetic medium layer also changes, and the corresponding absorption frequency shifts. When the magnetic permeability of the magnetic medium layer increases from 5.5 to 10, the absorption frequency shifts from 18.4 GHz to 13.9 GHz, a shift of 4.5 GHz.

[0083] While the embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to the embodiments described above. Various modifications may be made within the scope of knowledge possessed by a person skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features within the embodiments may be combined with one another unless there is a conflict.

Claims

1. A wave absorbing structure, characterized in that: include: Magnetic medium layer; wherein the magnetic medium layer is made of yttrium iron garnet, and the external magnetic field of the magnetic medium layer is 0-6000Oe; a first substrate layer, disposed at one end of the magnetic medium layer and having a through hole; wherein the first substrate layer is a copper plate, and the through hole is in the shape of a Jerusalem cross; a coil, wound around the first substrate layer and the magnetic medium layer, and adjusting the external magnetic field of the magnetic medium layer according to an external voltage; a second substrate layer, disposed at one end of the magnetic medium layer away from the first substrate layer, wherein the second substrate layer is a metal plate; The thickness of the first substrate layer is 1-2 mm, and the thickness of the magnetic medium layer is 0.5-2 mm.

2. A wave absorbing device, characterized in that: include: Several absorbing structures as claimed in claim 1; The plurality of wave absorbing structures are arranged in an array.

3. A method for manufacturing a wave absorbing structure, characterized in that: Applicable to the manufacture of a wave-absorbing structure, the wave-absorbing structure being the wave-absorbing structure according to claim 1, the method comprising: determining a first thickness, a through-hole structure, a magnetic permeability, and a second thickness according to an initial resonant frequency; manufacturing a first substrate layer according to the first thickness and the through-hole structure; manufacturing a magnetic medium layer according to the magnetic permeability and the second thickness; combining the first substrate layer and the magnetic medium layer to form a combined layer; A coil is wound around the combined layers.

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