A metasurface and wave absorber based on multi-unit periodic array distribution

Abstract

The application discloses a super-structure surface based on a multi-unit periodic array distribution, the super-structure surface is mainly formed by a plurality of micro-structure units arranged periodically, each micro-structure unit comprises a sub-unit A1, a sub-unit B1, a sub-unit A2 and a sub-unit B2, wherein the sub-unit A1 and the sub-unit A2 are in a central symmetric structure, and the sub-unit B1 and the sub-unit B2 are in a central symmetric structure; a wave absorber formed by the super-structure surface comprises a plurality of periodically arranged wave absorption units, each wave absorption unit comprises, from bottom to top, a conductive reflection layer, a medium interlayer, a micro-structure unit layer and a medium top layer; the wave absorber can realize more than 90% electromagnetic wave absorption rate on a frequency band of 8.31-41.75 GHz, and ensures no electromagnetic wave transmission, so that most of electromagnetic wave energy entering the wave absorber is lost under the action of medium loss and ohmic loss; meanwhile, the wave absorber has the characteristics of flexibility, easy preparation, good wave absorption effect and facilitation of integration, and is suitable for technical fields of electromagnetic shielding and microwave imaging.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of material electromagnetic shielding, in particular to a super-structure based on multi-unit periodic array distribution and wave absorber. BACKGROUND

[0002] The super-structure is a new type of artificially designed material, as a two-dimensional form of metamaterial, it is composed of a large number of periodically arranged sub-wavelength scale unit structures, which can accurately control the propagation characteristics of electromagnetic waves, such as reflection, refraction, polarization and phase. The emergence of super-structure technology provides unprecedented flexibility and accuracy for the manipulation of electromagnetic waves, which has wide application prospects in the fields of optics, antenna design, sensors, optoelectronics and stealth technology. Compared with traditional optical elements, super-structure has the advantages of being lighter, thinner and easier to integrate, and can realize complex optical functions such as holographic imaging, beam shaping and super-resolution imaging. With the progress of material science and nanofabrication technology, the design and manufacture of super-structure become more feasible, opening up new possibilities for future optical systems and electromagnetic field control technology applications.

[0003] At present, whether in military or civilian fields, the wave absorber made of super-structure has wide application, such as wave-absorbing super-structure material on the surface of radar antenna cover, electromagnetic radiation protection of broadcast, television transmitting station and household appliances, etc. However, the existing technology researches on super-structure material wave absorber made of super-structure are mostly single narrow-band wave absorber, while the perfect super-structure material wave absorber with wide frequency is more attractive, so the super-structure material wave absorber with wide frequency is the main development direction at present.

[0004] Therefore, it is necessary to design a new super-structure, so that the super-structure material wave absorber made of it has the effect of wide frequency absorption of electromagnetic waves, which can be widely used in the fields of microwave absorption, military stealth technology, wireless communication and test measurement, etc. SUMMARY

[0005] The purpose of the present application is to provide a super-structure based on multi-unit periodic array distribution and wave absorber, which can effectively solve the problems existing in the prior art.

[0006] To solve the above technical problems, the present application adopts the following technical scheme: a super-structure based on multi-unit periodic array distribution, the super-structure is mainly composed of a plurality of microstructure units arranged periodically, each microstructure unit includes sub-unit A1, sub-unit B1, sub-unit A2 and sub-unit B2, wherein sub-unit A1 and sub-unit A2 are in a center-symmetric structure, and sub-unit B1 and sub-unit B2 are in a center-symmetric structure.

[0007] The subunit A1 comprises a star structure and a quasi-back-shaped structure, the star structure takes a hexagonal star as a main body, and a hexagonal star is hollowed out equidistantly from the center of the hexagonal star; the quasi-back-shaped structure takes a cross as a main body, and a cross is hollowed out equidistantly from the center of the cross; the subunit B1 comprises a star structure, a quasi-back-shaped structure and a snowflake structure, the snowflake structure takes a circle as a main body, and a snowflake structure is hollowed out from the center of the circle, and the snowflake structure is composed of six petals, each of which is mutually mirror-symmetrical, and the lengths of the edges of each of the petals are the same.

[0008] Preferably, the number corresponding ratio of the quasi-back-shaped structure, the snowflake structure and the star structure in the super-structure is 10:2:4.

[0009] Preferably, the micro-structure units are arranged in a 4*4 array, the distances between the centers of the units are the same, and each of the subunits is arranged in a 2*2 array.

[0010] Preferably, the subunits A1 and the subunits B1 are arranged longitudinally, the first subunit in the array of the subunit A1 is a star structure, and the remaining subunits are quasi-back-shaped structures; in the subunit B1, the first subunit is a snowflake structure, the second subunit is a star structure, and the remaining subunits are quasi-back-shaped structures.

[0011] The application also discloses a wave absorber, comprising a wave absorbing unit, the wave absorbing unit comprises a conductive reflection layer, a medium interlayer, a super-structure based on a multi-unit periodic array distribution and a medium top layer which are sequentially attached from bottom to top, the super-structure based on a multi-unit periodic array distribution is the micro-structure unit according to any one of claims 1-4.

[0012] Preferably, the super-structure based on a multi-unit periodic array distribution and the conductive reflection layer are mainly composed of ITO with a thickness of 100 mu m and a surface resistivity of 5 Ohm / sq.

[0013] Preferably, the super-structure based on a multi-unit periodic array distribution is mainly composed of ITO with a thickness of 96 mu m and a surface resistivity of 80 Ohm / sq.

[0014] Preferably, the medium interlayer and the medium top layer are selected from a fluorinated ethylene propylene copolymer film with a dielectric constant of 2.0 and a thickness of 2 mm.

[0015] Beneficial effects: the superstructure surface in the application is mainly arranged by a plurality of microstructure units, and the microstructure unit is a 4*4 matrix array composed of three unique structure subunit structures; the superstructured material wave absorber made of the superstructure surface can realize electromagnetic wave absorption rate higher than 90% in the frequency band range of 8.31-41.75 GHz, so that most of the electromagnetic waves entering the wave absorber are lost under the action of dielectric loss and ohmic loss, and no electromagnetic wave transmission is ensured, in addition, the superstructure surface of the application has the characteristics of flexibility, easy preparation, good wave absorption effect and integration, and is suitable for technical fields such as electromagnetic shielding and microwave imaging. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings are included to provide a further understanding of the application, and constitute a part of the specification, illustrate the application together with the embodiments thereof, and explain the application without limiting the application.

[0017] In the drawings:

[0018] Figure 1 is the front view of the micro unit structure of the superstructure surface of the multi-unit periodic array distribution of the application;

[0019] Figure 2 is the periodic arrangement diagram of the superstructure surface of the multi-unit periodic array distribution of the application;

[0020] Figure 3 is a three-dimensional structure schematic diagram of the superstructured material wave absorber made of the micro unit structure of the superstructure surface of the multi-unit periodic array distribution of the application;

[0021] Figure 4 is the electromagnetic wave absorption characteristic curve diagram of the superstructured material wave absorber made of the superstructure surface of the multi-unit periodic array distribution of the application in the microwave band;

[0022] Marked number in the figure: 1, snowflake structure; 2, similar to the character structure; 3, star structure. DETAILED DESCRIPTION

[0023] The embodiments of the application will be described below in conjunction with the drawings of the embodiments of the application. The terms used in the embodiment part of the application are only used to explain the specific embodiments of the application, and are not intended to limit the application. The embodiments of the application will be described below in conjunction with the drawings.

[0024] Embodiment: as Figures 1-2As shown in the figure, a superstructure based on a multi-unit periodic array distribution, the superstructure is mainly composed of a plurality of microstructure units arranged periodically, each microstructure unit includes subunit A1, subunit B1, subunit A2 and subunit B2, wherein subunit A1 and subunit A2 are in a central symmetric structure, and subunit B1 and subunit B2 are in a central symmetric structure.

[0025] Subunit A1 includes star structure 3 and cross-shaped structure 2, the star structure 3 takes a hexagonal star as the main body, and a hexagonal star is hollowed out equidistantly with the center of the hexagonal star as the center; the cross-shaped structure 2 takes a cross as the main body, and a cross is hollowed out equidistantly with the center of the cross as the center, for example, referring to Figure 1 As shown in the figure, three structures cross-shaped structure 2 are composed of hollowing out a cube from the periphery of the cross, and a structure with the same pattern is hollowed out equidistantly with the center as the center; subunit B1 includes star structure 3 and cross-shaped structure 2, and snowflake structure 1, which takes a circle as the main body and a snowflake structure is hollowed out with the center of the circle as the center, and the snowflake structure is composed of six petals, each of which is mirror symmetric to each other, and the length of each edge is the same, and the centers of each structure have the same spacing and perfect geometric symmetry.

[0026] Among them, referring to Figure 1 The microstructure unit presents a 4*4 array distribution, and the spacing between the centers of each subunit is the same, and each subunit presents a 2*2 array distribution, subunit A1 and subunit B1 are arranged longitudinally, and the first position in the array of subunit A1 is a star structure, and the rest are cross-shaped structures; in subunit B1, the first position is a snowflake structure, the second position is a star structure, and the rest are cross-shaped structures;

[0027] As for the number of each structure, the corresponding proportion of the number of cross-shaped structures, snowflake structures and star fractal structures in the superstructure is 10:2:4.

[0028] The superstructure based on a multi-unit periodic array distribution is used to manufacture a super material wave absorber, and the application also discloses a wave absorber, referring to Figure 3 As shown in the figure, the wave absorber includes a wave absorbing unit, the wave absorbing unit includes a conductive reflection layer, a dielectric interlayer, a superstructure based on a multi-unit periodic array distribution and a dielectric top layer which are sequentially attached from bottom to top, the conductive reflection layer is mainly composed of ITO with a thickness of 100 μm and a surface resistivity of 5 Ohm / sq; the superstructure based on a multi-unit periodic array distribution is mainly composed of ITO with a thickness of 96 μm and a surface resistivity of 80 Ohm / sq; the dielectric interlayer and the dielectric top layer are fluorinated ethylene propylene copolymer films with a dielectric constant of 2.0 and a thickness of 2 mm.

[0029] In a specific embodiment, referring to Figure 1The specific parameters of the super-structured surface distributed with a multi-cell periodic array are as follows:

[0030] X=39mm; Y=34mm; A1=5.7mm; A2=A3=0.9mm; A4=2.7mm; R1=5mm; R2=3.2mm; B1=0.616mm; C1=2.592mm; C2=4.490mm; C3=1.095mm;

[0031] The super-structured surface based on a multi-cell periodic array is simulated and tested by using a CST microwave studio, Figure 4 is an absorption characteristic curve diagram of the super-structured material wave absorber made of the super-structured surface based on a multi-cell periodic array of embodiment 1 in a microwave wave band, which is drawn by Figure 4 It can be seen that the electromagnetic wave absorption rate of the super-structured material wave absorber made of the super-structured surface based on a multi-cell periodic array is higher than 90% in a frequency range of 8.31-41.75GHz; and the electromagnetic wave absorption rate is higher than 92.8% in a frequency range of 9.45-41.05GHz.

[0032] The preparation method of the above super-structured surface based on a multi-cell periodic array is as follows: the above three structures are etched by using a laser etching method, and after removing the material in the excess structure area, the wave absorption unit is obtained, and a plurality of wave absorption units are sequentially arranged together to obtain the super-structured surface based on a multi-cell periodic array.

[0033] The embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the above embodiments, and for those skilled in the art, after knowing the contents described in the present application, some equivalent transformations and substitutions can be made without departing from the principles of the present application, and these equivalent transformations and substitutions should also be considered as belonging to the protection scope of the present application.

Claims

1. A metasurface based on a multi-unit periodic array distribution, characterized in that, The metasurface is composed of a number of microstructure units arranged periodically. Each microstructure unit includes subunit A1, subunit B1, subunit A2 and subunit B2, wherein subunit A1 and subunit A2 are centrally symmetric, and subunit B1 and subunit B2 are centrally symmetric. Subunit A1 comprises a star-shaped structure and a square-shaped structure. The star-shaped structure is based on a hexagonal star, with a hexagonal star equidistantly cut out around its centroid. The square-shaped structure is based on a cross, with a cross equidistantly cut out around its centroid. Subunit B1 comprises a star-shaped structure and a square-shaped structure, and... The snowflake-shaped structure is based on a circle, with a snowflake structure cut out from the center of the circle. The snowflake structure consists of six petals, each of which is mirror-symmetrical to the others and has the same side length.

2. The metasurface based on a multi-unit periodic array distribution according to claim 1, characterized in that: The ratio of the number of fractal structures, snowflake structures, and star structures in the metasurface is 10:2:

4.

3. The metasurface based on a multi-unit periodic array distribution according to claim 1, characterized in that: The microstructure units are arranged in a 4x4 array with equal spacing between their centroids, and each subunit is arranged in a 2x2 array.

4. A metasurface based on a multi-unit periodic array distribution according to claim 3, characterized in that: The sub-units A1 and B1 are arranged vertically, and the first position in the array of sub-unit A1 is a star-shaped structure, while the rest are square-shaped structures; in sub-unit B1, the first position is a snowflake-shaped structure, the second position is a star-shaped structure, and the rest are square-shaped structures.

5. A microwave absorber, characterized in that: It includes a wave-absorbing unit, which comprises, from bottom to top, a conductive reflective layer, a dielectric interlayer, a metasurface based on a multi-unit periodic array distribution, and a dielectric top layer, wherein the metasurface based on a multi-unit periodic array distribution is the metasurface based on a multi-unit periodic array distribution as described in any one of claims 1-4.

6. The absorber according to claim 5, characterized in that: The metasurface and conductive reflective layer based on a multi-unit periodic array distribution are composed of ITO with a surface resistivity of 5 Ohm / sq and a thickness of 100 μm.

7. The absorber according to claim 5 or 6, characterized in that: The metasurface based on a multi-unit periodic array distribution is composed of ITO with a surface resistivity of 80 Ohm / sq and a thickness of 96 μm.

8. The absorber according to claim 5, characterized in that: The dielectric interlayer and the dielectric top layer are made of fluorinated ethylene propylene copolymer film with a dielectric constant of 2.0 and a thickness of 2 mm.

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