CN118099767A - Wave absorbing structure - Google Patents

Abstract

The application provides a wave-absorbing structure, which comprises: a wave-absorbing substrate and at least one wave-absorbing unit on the wave-absorbing substrate; the wave absorbing unit comprises a wave absorbing wall and a plurality of cavities surrounded by the wave absorbing wall; the plurality of cavities comprise first cavities which are intersected, and second cavities which are positioned at the end parts of each first cavity; each second cavity is communicated with the corresponding first cavity, and the cross section width of the first cavity is smaller than that of the second cavity. In the technical scheme, the wave absorbing units are adopted to form the cavities with different cross sectional areas, so that the frequency ranges absorbed by the two cavities are different, the integral range of the absorbable frequency of the wave absorbing structure is enlarged, and the wave absorbing effect of the wave absorbing structure is improved.

Description

Wave absorbing structure

Technical Field

The application relates to the technical field of electromagnetic wave protection, in particular to a wave absorbing structure.

Background

Wave absorbing materials are often used in buildings or products to absorb waves so as to improve the electromagnetic protection effect of the buildings or products. At present, most wave-absorbing materials realize electromagnetic wave energy loss by adding wave-absorbing agents, and meanwhile, in order to reduce reflection of surfaces, structural design is often aided, so that electromagnetic waves can be incident into the materials. The structures commonly used are porous, pyramid or multilayer structures. The frequency bands of the porous and multilayer structures are generally narrower, and the low-frequency absorption effect of the pyramid structure is slightly poorer. And when the electromagnetic wave is obliquely incident, the reflection is enhanced, and the absorption effect is deteriorated.

Disclosure of Invention

The application provides a wave-absorbing structure, which increases the frequency bandwidth of a wave-absorbing material, improves the wave-absorbing performance of the wave-absorbing material, and particularly improves the absorption effect of the wave-absorbing material on electromagnetic waves when the electromagnetic waves are obliquely incident.

The application provides a wave-absorbing structure, which comprises: a wave-absorbing substrate and at least one wave-absorbing unit on the wave-absorbing substrate; the wave absorbing unit comprises a wave absorbing wall and a plurality of cavities surrounded by the wave absorbing wall; the plurality of cavities comprise first cavities which are intersected, and second cavities which are positioned at the end parts of each first cavity; wherein,

Each second cavity is communicated with a corresponding first cavity, and the cross-sectional width of the first cavity is smaller than that of the second cavity.

In the technical scheme, the wave absorbing units are adopted to form the cavities with different cross sectional areas, so that the frequency ranges absorbed by the two cavities are different, the integral range of the absorbable frequency of the wave absorbing structure is enlarged, and the wave absorbing effect of the wave absorbing structure is improved.

In a specific embodiment, the first cavity comprises a first sub-cavity and a second sub-cavity which are crossed, and the first sub-cavity and the second sub-cavity are mutually perpendicular; wherein,

Each end of the first subcavity and each end of the second subcavity are provided with a second cavity.

In a specific implementation manner, the number of the wave absorbing units is a plurality, and the plurality of cavity arrays are arranged; wherein, the cavities between adjacent wave absorbing units are communicated.

In a specific embodiment, adjacent second cavities in adjacent wave-absorbing units are in communication.

In a specific embodiment, the wave absorbing unit is integrally formed with the wave absorbing substrate.

In a specific embodiment, the wave-absorbing wall is a straight wall or the wave-absorbing wall is a structure with a top tip and a bottom width.

In a specific embodiment, the wave-absorbing wall includes a first wall and a second wall, the second wall enclosing a plurality of the cavities; the first wall is nested outside the second wall body and is arranged at intervals with the second wall body; wherein,

The first wall comprises a first straight wall and a first wavy wall arranged on the first straight wall; the wave propagation direction of the first wave-shaped wall is along the height direction of the first straight wall;

The second wall comprises a second straight wall and a second wavy wall arranged on the second straight wall; the propagation direction of the waves of the first wavy wall is along the height direction of the second straight wall.

In a specific embodiment, the first undulating wall and the second undulating wall are identical in shape; and the first straight wall is lower than the second straight wall in height.

In a specific embodiment, the linear distance between the peaks and valleys of the first undulating wall is equal to the thickness of the first straight wall; and/or the number of the groups of groups,

The linear distance between the peaks and the troughs of the second wavy wall is equal to the thickness of the second straight wall.

In a specific embodiment, the difference in height between the first undulating wall and the second undulating wall is between 0.5 and 2 wavelengths.

Drawings

Fig. 1 is a schematic structural diagram of a wave absorbing structure according to an embodiment of the present application;

fig. 2 is a schematic diagram illustrating electric field strength simulation of a wave-absorbing structure according to an embodiment of the present application;

fig. 3 is a schematic diagram of electric field vector strength simulation of a wave-absorbing structure according to an embodiment of the present application;

FIG. 4 is a schematic diagram of the wave-absorbing structure shown in FIG. 1;

FIG. 5 is a schematic diagram of a prior art planar wave-absorbing structure;

Fig. 6 is a schematic structural diagram of another wave-absorbing structure according to an embodiment of the present application;

fig. 7 is a schematic structural diagram of a wave-absorbing wall with a wave-absorbing structure according to an embodiment of the present application;

Fig. 8 is a schematic view of a partition of a wave-absorbing wall along a vertical direction according to an embodiment of the present application;

Fig. 9 and 10 are simulation diagrams of the wave-absorbing structure shown in fig. 6, in which electromagnetic waves are obliquely incident and normally incident.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings.

It is noted that unless otherwise defined, technical or scientific terms used in one or more embodiments of the present disclosure should be taken in a general sense as understood by one of ordinary skill in the art to which the present disclosure pertains. The use of the terms "first," "second," and the like in one or more embodiments of the present description does not denote any order, quantity, or importance, but rather the terms "first," "second," and the like are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that elements or items preceding the word are included in the element or item listed after the word and equivalents thereof, but does not exclude other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", etc. are used merely to indicate relative positional relationships, which may also be changed when the absolute position of the object to be described is changed.

In order to facilitate understanding of the wave absorbing structure provided by the embodiment of the application, an application scene thereof is first described. The wave-absorbing structure provided by the embodiment of the application can be applied to different wave-absorbing buildings or wave-absorbing products. When current wave-absorbing structure is realizing the wave-absorbing, on the one hand absorb the wave through the material, on the other hand realize the wave-absorbing through the structure of wave-absorbing structure, but whatever kind is adopted, current wave-absorbing structure can absorb the scope of frequency narrower, influences the wave-absorbing effect, and when the oblique incidence in general moreover, the surface reflection is strengthened, and the wave-absorbing effect weakens. Therefore, the embodiment of the application provides a wave-absorbing structure so as to improve the wave-absorbing effect of the wave-absorbing structure. The following describes the wave absorbing structure provided by the embodiment of the application in detail with reference to the specific drawings.

In the wave absorption process, the wave absorption performance of the material depends on the amount of electromagnetic waves entering the material and the consumption of electromagnetic wave energy by the material, and the electromagnetic waves entering the material are determined by the impedance of the material, so that the electromagnetic waves of the material with matched impedance can enter in a large amount. Therefore, the impedance of the material is designed in a gradient way, so that the entering amount of electromagnetic waves can be effectively increased, and a good wave absorbing effect is achieved. The following describes in detail the wave-absorbing structure provided by the embodiment of the application with reference to the accompanying drawings.

Referring to fig. 1, a wave-absorbing structure provided in an embodiment of the present application includes a wave-absorbing substrate 100 and a wave-absorbing unit 200 disposed on the wave-absorbing substrate 100. It should be understood that the number of the wave-absorbing units 200 may be one or more, and when the number of the wave-absorbing units 200 is plural, the plurality of wave-absorbing units 200 may be arrayed. In wave absorption, the wave-absorbing substrate 100 and the wave-absorbing unit 200 can be used for absorbing waves, wherein the wave-absorbing substrate 100 absorbs waves through the material of the wave-absorbing substrate, the wave-absorbing unit 200 absorbs waves through the material of the wave-absorbing unit on one hand, and reflects waves through the cavity structure inside the wave-absorbing unit on the other hand, so that the waves are counteracted in the cavity to realize wave absorption.

With continued reference to fig. 1, the wave absorbing unit 200 according to the embodiment of the present application absorbs the wave from the wall 210 and a plurality of cavities surrounded by the wall 210; wherein the opening direction of the cavity faces away from the wave-absorbing substrate 100. For units absorbing different frequencies, the cavities are arranged in different ways. Specifically, the plurality of cavities includes first cavities 230 in a cross-shape, and second cavities 220 at ends of each first cavity 230; each second cavity 220 is communicated with the corresponding first cavity 230, the cross-sectional width of the first cavity 230 is smaller than that of the second cavity 220, and the wave-absorbing frequency bands corresponding to the first cavity 230 and the second cavity 220 are different.

In a specific example, the width of the cross-section of the first cavity 230 is smaller than the width of the cross-section of the second cavity 220. Illustratively, the width of the cross-section of the first cavity 230 is D1 and the width of the cross-section of the second cavity 220 is D2, then D1 < D2 is satisfied. In addition, the dimensions of D1 satisfy: the wave path difference formed by the electromagnetic wave after being reflected in the first cavity 230 is n+1/2 wavelength of the corresponding frequency, so that the wave reflected by the side wall of the first cavity 230 can be mutually offset with the incident wave, thereby achieving the purpose of absorption. Similarly, D2 is sized in the same manner so that the wave reflected back through the sidewall of the second cavity 220 can cancel the incident wave for absorption purposes.

As can be seen from the above description, in the embodiment of the present application, in design, the cross-sectional dimensions of the first cavity 230 and the second cavity 220 can be set corresponding to the frequency range to be absorbed, so that the first cavity 230 and the second cavity 220 can absorb the waves in different frequency ranges, thereby enhancing the wave absorbing effect of the wave absorbing unit 200. In other words, in the solution provided in the embodiment of the present application, the wave absorbing unit 200 is used to form the cavities with different cross-sectional areas, so that the frequency ranges absorbed by the two cavities are different, thereby increasing the overall range of the absorbable frequency of the wave absorbing structure and improving the wave absorbing effect of the wave absorbing structure.

When forming the first cavity 230, the first cavity 230 is a crossed cavity. Specifically, it contains two subcavities, for the convenience of description, will be named as first subcavity 231 and second subcavity 232 respectively to first subcavity 231 and second subcavity 232 alternately form X shape's structure, and when this mode set up, electromagnetic wave when two cavity lateral walls take place the reflection, wave path difference is different, causes interference destructive electromagnetic wave frequency difference, widens absorption frequency channel, improves the wave absorbing effect.

In addition, when the second cavities 220 are disposed, the second cavities 220 are communicated with the first cavities 230, in which a second cavity 220 is disposed at an end of each first cavity 230, and each second cavity 220 is communicated with the corresponding first cavity 230. Specifically, the number of the second cavities 220 is four, wherein two second cavities 220 are disposed at two ends of the first sub-cavity 231, and the other two second cavities 220 are disposed at two ends of the second sub-cavity 232. In the wave-absorbing unit 200 formed in the above-described arrangement, the four second cavities 220 are located at the outer sides and are surrounded in a ring shape, and the first cavity 230 is located at the central area and communicates the four second cavities 220 through an X-shaped structure.

In an alternative, the first sub-cavity 231 and the second sub-cavity 232 are perpendicular to each other, and each end of the first sub-cavity 231 and the second sub-cavity 232 is provided with a second cavity 220, so that the wave absorbing unit 200 forms a self-symmetrical structure. Therefore, the first cavity 230 and the second cavity 220 can correspond to the incident wave, so that the wave absorbing effect is improved.

In an alternative, the second cavity 220 may be a square cavity, and the first subcavity 231 or the second subcavity 232 communicates with a corner of the second cavity 220. Such as the first sub-chamber 231 or the second sub-chamber 232, is parallel to a diagonal of the second chamber 220.

In the embodiment of the present application, when the number of the wave absorbing units 200 is plural, the plural cavity arrays are arranged. And when specifically arranged, the cavities between adjacent wave-absorbing units 200 are communicated. So that the cavities in the plurality of wave absorbing units 200 can be communicated, thereby improving the coverage rate of the cavities and absorbing more waves.

When the plurality of wave-absorbing units 200 are communicated, adjacent second cavities 220 in adjacent wave-absorbing units 200 are communicated. In one exemplary embodiment, adjacent wave absorbing units 200 may be used by sharing a second cavity 220. In the two adjacent wave-absorbing units 200, the two first sub-cavities 231 have the same length direction, and when in communication, a second cavity 220 is disposed between the two first sub-cavities 231, and the two first sub-cavities 231 are arranged on two opposite sides of the diagonal of the second cavity 220.

In the wave-absorbing process, the side walls of the first cavity 230 and the second cavity 220 are the wave-absorbing walls 210, and the incident wave irradiates the wave-absorbing walls 210 and is reflected by the wave-absorbing walls 210. In one embodiment, the wave absorbing wall 210 is a straight wall or the wave absorbing wall 210 is entirely a structure with a top tip and a bottom width. As shown in fig. 1, the wave-absorbing wall 210 illustrated in fig. 1 is a wall having a triangular cross section, and may be a trapezoid in addition to the triangular cross section. When the wave-absorbing wall 210 has a structure with a narrow top and a wide bottom, the absorbing effect of the wave-absorbing structure on the obliquely incident electromagnetic wave can be increased.

When the wave-absorbing unit 200 and the wave-absorbing substrate 100 are specifically manufactured, the wave-absorbing unit 200 and the wave-absorbing substrate 100 are integrally formed, thereby facilitating the manufacture of the wave-absorbing structure. Of course, the wave-absorbing unit 200 and the wave-absorbing substrate 100 may also be in a split structure, for example, the wave-absorbing unit 200 and the wave-absorbing substrate 100 are fixedly connected by bonding.

It should be understood that the wave-absorbing unit 200 is in an integral or separate structure with the wave-absorbing base 100. The wave-absorbing substrate 100 and the wave-absorbing unit 200 provided by the embodiment of the application are both made of wave-absorbing materials, and the wave-absorbing materials are materials capable of absorbing and attenuating electromagnetic waves incident into the materials and converting the electromagnetic waves into energy with other properties. The material mainly comprises an absorbent and a matrix material, wherein the absorbent is a substance which can absorb and reflect electromagnetic waves, and ferrite, carbonyl iron, conductive high polymer, metal oxide, carbon black, graphite and the like are commonly used. The matrix material is a carrier of the absorbent, can bear and disperse the absorbent, and has certain mechanical properties, such as rubber, soft polyurethane foam, hard styrene foam and the like.

Loss mechanisms can be categorized into electrically-lossy, magnetically-lossy, and dielectric-lossy wave absorbers. The electrically lossy absorber mainly comprises conductive polymers, carbon materials, and the like. They usually have a high dielectric constant and convert electromagnetic energy into electrical energy by utilizing electronic transitions and migration to form current. Dielectric loss type absorbents comprise materials such as zinc oxide, barium titanate, silicon carbide, titanium nitride, manganese dioxide and the like, and electromagnetic waves are attenuated in a microwave frequency band mainly by utilizing mechanisms such as electric dipole polarization, relaxation, interface polarization and the like; the magnetic loss type absorber mainly comprises materials such as iron, cobalt, nickel, ferrite, ferroferric oxide and the like, and electromagnetic waves are mainly lost by the mechanisms such as hysteresis loss, interface loss, domain wall resonance loss, natural resonance loss, eddy current loss and the like.

In order to facilitate understanding of the effect of the wave-absorbing structure provided by the embodiment of the present application, a structure of the wave-absorbing structure shown in fig. 1, in which the wave-absorbing wall is a straight wall, is taken as an example, and simulation results thereof are shown in fig. 2 to 3.

The electric field strength simulation is shown in fig. 2, and the electric field vector simulation is shown in fig. 3. As shown in fig. 2, in this frequency band, electromagnetic wave energy of the cross structure (i.e., the first cavity 230) is significantly reduced, where the electromagnetic wave energy is lost, the electromagnetic wave loss gradually decreases as the wave-absorbing wall 210 expands toward the inside, and the loss of the corresponding substrate 100 in the second cavity 220 is lower. When the electromagnetic wave is incident on the wave-absorbing wall 210, reflection and refraction occur on the surface of the structure, the intensity of the electromagnetic wave incident on the wave-absorbing substrate 100 is reduced compared with the intensity of the surrounding free space, the intensity of the electromagnetic wave in the second cavity 220 is lower than the intensity of the electromagnetic wave in the surrounding free space, and as shown in fig. 3, a part of the electromagnetic wave is scattered due to reflection and refraction between the walls, so that the direction of the electric field vector is changed, and the intensity of the electric field vector at a part of the positions is weakened.

In order to facilitate understanding of the wave-absorbing effect of the wave-absorbing structure provided by the embodiment of the present application, the wave-absorbing structure shown in fig. 1 is simulated with the existing wave-absorbing structure to verify the wave-absorbing effect thereof. Wherein, the existing wave-absorbing structure adopts a flat plate-shaped wave-absorbing structure. The parameters of the wave-absorbing structure in fig. 1 are: a=17, h=40, b=10, t=45, l=180, the size 175 of the absorbing element, the size of the absorbing substrate being 180 x 180mm. The wave absorbing unit has a height h, the wave absorbing substrate has a thickness b, the cross section of the wave absorbing wall is triangular, the bottom width of the wave absorbing wall is t, and the height h. The wave-absorbing wall and the wave-absorbing substrate are made of paraffin base materials doped with 8% of carbon black by mass. Similarly, the material of the comparative flat plate type wave-absorbing structure also adopts a paraffin matrix material doped with 8% by mass of carbon black.

Referring to fig. 4 and fig. 5, fig. 4 is a schematic simulation diagram of a wave absorbing structure according to an embodiment of the present application, and fig. 5 is a schematic simulation diagram in the prior art. As can be seen from FIG. 4, compared with the prior art, the wave absorbing structure provided by the embodiment of the application has greatly reduced reflectivity, the reflectivity of 2-18 GHz is below-10 dB, the minimum reflectivity reaches-38 dB, and the frequency bandwidth is increased. As can be seen from fig. 5, the wave-absorbing structure in the prior art has a frequency band width of only 0.4GHz below-10 dB due to high surface reflectivity. Therefore, the structure can greatly enhance the wave absorbing performance of the material.

Referring to fig. 6 and 7 together, fig. 6 shows a modified structure of the wave-absorbing structure, and fig. 7 shows a schematic structural view of the wave-absorbing wall. The wave absorbing wall 210 provided by the embodiment of the present application is not limited to the straight wall shown in fig. 1, but may be other types of walls. In a specific embodiment, the wave-absorbing wall 210 includes a first wall 212 and a second wall 211, and the second wall 211 encloses the plurality of cavities (the pair of cavities 230 and the second cavity 220); the first wall 212 is nested outside the second wall 211 and is spaced apart from the second wall 211, i.e. a cavity is also formed between the first wall 212 and the second wall 211. When the first wall 212 and the second wall 211 are specifically disposed, the first wall 212 and the second wall 211 each include a straight wall and a wavy wall. Specifically, the straight wall is fixedly connected to the wave-absorbing base 100, and the wave-absorbing wall 210 is located above the straight wall.

Specifically, the first wall 212 includes a first straight wall 2121 and a first wavy wall 2122 provided on the first straight wall 2121, and a propagation direction of the wavy shape of the first wavy wall 2122 is along a height direction of the first straight wall 2121. And the second wall 211 includes a second straight wall 2111 and a second wavy wall 2112 provided on the second straight wall 2111; the direction of propagation of the undulations of the first undulating wall 2122 is along the height of the second straight wall 2111. As can be seen in conjunction with fig. 7, the height direction of the first and second straight walls 2121 and 2111 is along the vertical direction, and the first and second wavy walls 2122 and 2112 extend along the height direction of the first and second straight walls 2121 and 2111, forming a curved wavy shape on top of the first and second walls 212 and 211. The wave crests (first wave wall 2122 and second wave wall 2112) may also be formed by arcs or trigonometric functions as sides.

When the first wall 212 and the second wall 211 are provided in the above-described manner, a straight surface (straight wall) and a folded surface (wavy wall) are formed in the height direction. To form different impedance matching regions in the height direction. Specifically, one impedance area of the overlapping area of the first straight wall 2121 and the second straight wall 2111 and another impedance area of the first wavy wall 2122 and the second wavy wall 2112 may be formed.

With continued reference to fig. 7, the shape is the same in the first undulating wall 2122 and the second undulating wall 2112; and the first straight wall 2121 is lower than the height of the second straight wall 2111. In fig. 7, the first wavy wall 2122 and the second wavy wall 2112 each include a crest and a trough, and the first wavy wall 2122 and the second wavy wall 2112 have the same shape. When the height of the first straight wall 2121 is lower than the height of the second straight wall 2111, the height of the first wavy wall 2122 is lower than the height of the second wavy wall 2112. In a particular embodiment, the height difference between the first straight wall 2121 and the second straight wall 2111 is between 0.5 and 2 wavelengths. I.e., the first undulating wall 2122 and the second undulating wall 2112 are between 0.5 and 2 wavelengths. Accordingly, the inclination direction of the portion where the first wavy wall 2122 overlaps the second wavy wall 2112 is the same.

In a particular embodiment, the linear distance between the peaks and valleys of the first undulating wall 2122 is equal to the thickness of the first straight wall 2121; and/or, the linear distance between the peaks and valleys of the second undulating wall 2112 is equal to the thickness of the second straight wall 2111. I.e., the thickness of the first undulating wall 2122 is less than the thickness of the first straight wall 2121. Similarly, the thickness of the second wavy wall 2112 is less than the thickness of the second straight wall 2111 to form a fourth area at the portion of the first straight wall 2121 overlapping the first straight wall 2121, and the portion of the second straight wall 2111 overlapping the first wavy wall 2122 forms a third area; the portion of the second undulating wall 2112 that overlaps the first undulating wall 2122 forms a second region and the portion of the second undulating wall 2112 that is higher than the first undulating wall 2122 forms a first region. As can be seen from fig. 7 and 8, along the top-to-bottom partition of the wave-absorbing wall 210, the filling rate of the wave-absorbing matrix is gradually increased, so that the electromagnetic wave is more likely to enter the material and be lost due to impedance matching formed by the stepped arrangement and the difference of the upper and lower filling rates when the electromagnetic wave is obliquely incident. Multiple reflections occur more easily in the air cavity formed by the structure, thereby absorbing frequencies over a wider frequency range. The wave-shaped top has the effects that when the electromagnetic wave obliquely enters the surface, the electromagnetic wave can enter the wave-shaped position, and at the moment, the side spike on the wave-shaped surface also plays roles of impedance matching and multiple reflection, the electromagnetic wave is lost at the wave-shaped top, and the surface reflection is weakened, so that a good wave-absorbing effect is achieved on oblique incidence.

Referring to fig. 9 and 10, fig. 9 illustrates a schematic diagram of the electromagnetic wave obliquely incident to the wave-absorbing structure, and fig. 10 illustrates a schematic diagram of the electromagnetic wave normally incident to the wave-absorbing structure. Wherein h=38b=10l=180; wherein H is the height of the structural layer, b is the thickness of the substrate, and l is the width of the wave absorbing unit. In fig. 9, the incident direction of the electromagnetic wave is 45 degrees oblique incidence; in fig. 10, electromagnetic waves are incident perpendicular to the plate surface. When electromagnetic waves are obliquely incident at a certain angle, the frequency range below-10 dB is 3-18 GHz, when the electromagnetic waves are normally incident, the frequency range below-10 dB is 1.5-2.6 GHz and 4-18 GHz, and the low-frequency absorption effect is slightly low during oblique incidence, but the same frequency bandwidth can be maintained, so that the effect of improving the wave absorption performance during oblique incidence is remarkable.

The present disclosure is intended to embrace all such alternatives, modifications and variances which fall within the broad scope of the appended claims. Any omissions, modifications, equivalents, improvements, and the like, which are within the spirit and principles of the one or more embodiments of the disclosure, are therefore intended to be included within the scope of the disclosure.

The foregoing is merely illustrative embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about variations or substitutions within the technical scope of the present application, and the application should be covered. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims (10)

1. A wave absorbing structure, comprising: a wave-absorbing substrate and at least one wave-absorbing unit on the wave-absorbing substrate; the wave absorbing unit comprises a wave absorbing wall and a plurality of cavities surrounded by the wave absorbing wall; the plurality of cavities comprise first cavities which are intersected, and second cavities which are positioned at the end parts of each first cavity; wherein,

Each second cavity is communicated with a corresponding first cavity, and the cross-sectional width of the first cavity is smaller than that of the second cavity.

2. The wave absorbing structure of claim 1, wherein the first cavity comprises a first sub-cavity and a second sub-cavity that intersect, and the first sub-cavity and the second sub-cavity are perpendicular to each other; wherein,

Each end of the first subcavity and each end of the second subcavity are provided with a second cavity.

3. The wave absorbing structure according to claim 1, wherein the number of the wave absorbing units is plural, and the plural cavity arrays are arranged; wherein, the cavities between adjacent wave absorbing units are communicated.

4. A wave-absorbing structure according to claim 3, wherein adjacent second cavities in adjacent wave-absorbing units are in communication.

5. The wave absorbing structure of claim 1, wherein the wave absorbing unit is integrally formed with the wave absorbing substrate.

6. The wave-absorbing structure according to any one of claims 1 to 5, wherein the wave-absorbing wall is a straight wall or the wave-absorbing wall is entirely a structure with a top tip and a bottom width.

7. The wave absorbing structure of any one of claims 1-5, wherein the wave absorbing wall comprises a first wall and a second wall, the second wall enclosing a plurality of the cavities; the first wall is nested outside the second wall body and is arranged at intervals with the second wall body; wherein,

The first wall comprises a first straight wall and a first wavy wall arranged on the first straight wall; the wave propagation direction of the first wave-shaped wall is along the height direction of the first straight wall;

The second wall comprises a second straight wall and a second wavy wall arranged on the second straight wall; the propagation direction of the waves of the first wavy wall is along the height direction of the second straight wall.

8. The wave absorbing structure of claim 7, wherein the first and second wave walls are the same shape; and the first straight wall is lower than the second straight wall in height.

9. The wave absorbing structure of claim 8, wherein a linear distance between peaks and valleys of the first undulating wall is equal to a thickness of the first straight wall; and/or the number of the groups of groups,

The linear distance between the peaks and the troughs of the second wavy wall is equal to the thickness of the second straight wall.

10. The wave absorbing structure of claim 8, wherein the difference in height between the first undulating wall and the second undulating wall is between 0.5 and 2 wavelengths.