Metasurface unit and dual-band shielding metasurface structure with metasurface unit

Abstract

The invention provides a metasurface unit and a dual-band shielding metasurface structure with the metasurface unit. The metasurface unit comprises a dielectric substrate; the metal layer is arranged on the dielectric substrate, the metal layer comprises an external structure and an internal structure arranged in the external structure, the internal structure comprises a main ring section arranged at the center of the external structure and at least three first metal sections arranged at intervals in the circumferential direction of the main ring section, and a second metal section is arranged between every two adjacent first metal sections; the internal structure forms a closed loop structure; wherein related parameters of the metal layer are adjustably set, so that the problem that in the prior art, a frequency selective surface unit is poor in shielding performance under large-angle oblique incidence is solved.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and in particular to a metasurface unit and a dual-band shielded metasurface structure having the same. Background Art

[0002] At present, with the rapid development of wireless communications, the environmental problems caused by electromagnetic radiation are becoming more and more serious. A large number of wireless devices close to each other will also generate electromagnetic interference, which will affect the working performance of each device. Therefore, electromagnetic shielding is needed to suppress these interferences, especially in some specific environments, such as special research centers, hospitals, military facilities, etc., where signal shielding is even more necessary. Unlike electrostatic shielding and static magnetostatic shielding, microwave frequency band shielding belongs to high-frequency electromagnetic field shielding, and often only a thin layer is needed to shield electromagnetic waves in the radio frequency band. However, in the face of various electromagnetic compatibility problems caused by electromagnetic interference to equipment and the environment, it is necessary to introduce new materials and structures based on metal covers to selectively shield electromagnetic waves.

[0003] In the past few decades, frequently used high-performance shielding materials include metal films, broadband absorbers, and metasurfaces. In recent years, artificial material metasurfaces used to adjust and select electromagnetic waves of specific frequencies have made significant progress in research. Frequency selective surface (FSS), as a new type of metasurface, has the advantages of low cost, good shielding effect, and easy processing. Due to its importance in radar stealth technology, frequency selective surfaces have always attracted much attention. At present, it is also mainly used in the fields of electromagnetic shielding of microwave devices and vehicle-mounted communication systems.

[0004] However, for a frequency selective surface unit of conventional size, its performance usually changes greatly under large-angle oblique incidence, which leads to problems of insufficient shielding performance and insufficient angular stability. Summary of the invention

[0005] The main purpose of the present invention is to provide a metasurface unit and a dual-band shielded metasurface structure having the same, so as to solve the problem that the frequency selective surface unit in the prior art has poor shielding performance under large-angle oblique incidence.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a metasurface unit is provided, comprising: a dielectric substrate; a metal layer, arranged on the dielectric substrate, the metal layer comprising an external structure and an internal structure arranged inside the external structure, the internal structure comprising a main ring segment arranged at the center of the external structure and at least three first metal segments arranged at intervals along the circumferential direction of the main ring segment, a second metal segment is arranged between each adjacent two first metal segments so that the internal structure forms a closed-loop structure; wherein relevant parameters of the metal layer can be adjusted.

[0007] Furthermore, the length range L of the first metal segment is m Meet: 2.3mm≤L m ≤2.5mm.

[0008] Furthermore, in two adjacent metasurface units, the preset spacing between the two external structures can be adjusted; wherein the preset spacing S satisfies: 0.2mm≤S≤0.6mm.

[0009] Furthermore, the main ring segment is a circular ring structure, and the radius of the main ring segment is R s Satisfy: 0.4mm≤R s ≤1mm.

[0010] Furthermore, the second metal segment includes two arc segments, one end of the two arc segments is respectively connected to the two first metal segments, and the other ends of the two arc segments are respectively provided with fixed segments and are connected to each other to form a symmetrical structure.

[0011] Furthermore, the diameter of the arc segment is L a Satisfy: 2mm≤L a ≤2.2mm; and / or, the fixed segment is a circular structure, and the radius of the fixed segment is L b Satisfy: 0.1mm≤L b ≤1mm.

[0012] Furthermore, the external structure is a regular hexagonal ring structure; wherein the thickness W of each side of the external structure satisfies: 0.2mm≤W≤0.6mm; and / or, the dielectric substrate is a regular hexagonal plate structure, and the length L of each side of the dielectric substrate satisfies: 8mm≤L≤10mm.

[0013] Furthermore, the thickness h of the dielectric substrate satisfies: 2 mm ≤ h ≤ 4 mm.

[0014] Furthermore, the main ring segment, the first metal segment and the second metal segment are an integrally formed structure.

[0015] According to another aspect of the present invention, a dual-band shielding metasurface structure is provided, comprising a plurality of the metasurface units mentioned above, wherein the plurality of metasurface units are arranged in a honeycomb structure.

[0016] According to the technical solution of the present invention, the metasurface unit includes a dielectric substrate and a metal layer; the metal layer is arranged on the dielectric substrate, the metal layer includes an external structure and an internal structure arranged inside the external structure, the internal structure includes a main ring segment arranged at the center of the external structure and at least three first metal segments arranged at intervals along the circumferential direction of the main ring segment, and a second metal segment is arranged between two adjacent first metal segments, so that the internal structure forms a closed loop structure; wherein the relevant parameters of the metal layer can be adjusted. With the above arrangement, the dielectric substrate of the equivalent circuit of the entire metasurface unit can be equivalent to impedance, and the internal structure and the external structure of the metal layer can be equivalent to two parallel circuits of series resonance respectively; wherein the internal structure is equivalent to inductance, the spacing between the main ring segment and the second metal segment of the internal structure and the spacing between the inner circumferential walls of the main ring segment are equivalent to capacitance to form a series resonance, and the spacing between the main ring segment and the second metal segment can be adjusted by adjusting the length of the first metal segment, and the radius of the main ring segment can be adjusted to adjust the relevant parameters of the internal structure. In this way, the external structure is used to control the lower frequency band, and the internal structure is used to control the higher frequency band. By replacing the dielectric substrates with different relative dielectric constants or different thicknesses, or by adjusting the relevant parameters of the metal layer, the shielding effect of any target frequency band can be achieved, so as to achieve selective shielding of microwave signals in a specific frequency band. It has the characteristics of good shielding performance, polarization insensitivity and extremely high angle stability. The structure is miniaturized, simple and beautiful, thereby solving the problem of poor shielding performance of the frequency selective surface unit under large-angle oblique incidence in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 A schematic structural diagram showing a first viewing angle of an embodiment of a super surface unit according to the present invention;

[0019] Figure 2 A schematic structural diagram showing a second viewing angle of an embodiment of a supersurface unit according to the present invention;

[0020] Figure 3 A schematic structural diagram of an embodiment of a dual-band shielding metasurface structure according to the present invention is shown;

[0021] Figure 4 An equivalent circuit diagram of an embodiment of a dual-band shielding metasurface structure according to the present invention is shown;

[0022] Figure 5The transmission coefficient result diagram of the embodiment of the dual-band shielding metasurface structure according to the present invention under horizontal polarization wave incidence is shown, where a, b, c, and d represent oblique incidence angles of 0°, 30°, 60°, and 80°, respectively;

[0023] Figure 6 The transmission coefficient result diagram of the embodiment of the dual-band shielding metasurface structure according to the present invention under vertical polarization wave incidence is shown, where a, b, c, and d represent oblique incidence angles of 0°, 30°, 60°, and 80°, respectively;

[0024] Figure 7 A first result diagram showing the transmission coefficient of an embodiment of a dual-band shielding metasurface structure according to the present invention under vertical incidence of electromagnetic waves;

[0025] Figure 8 A second result graph of the transmission coefficient of an embodiment of the dual-band shielding metasurface structure according to the present invention under vertical incidence of electromagnetic waves is shown.

[0026] The above drawings include the following reference numerals:

[0027] 10. Dielectric substrate; 20. Metal layer; 30. External structure; 40. Internal structure; 41. Main ring segment; 42. First metal segment; 43. Second metal segment; 430. Arc segment; 431. Fixed segment. DETAILED DESCRIPTION

[0028] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0029] In order to solve the problems in the prior art of poor shielding performance and low angular stability of frequency selective surface units under large-angle oblique incidence, the present invention provides a metasurface unit and a dual-band shielding metasurface structure having the same.

[0030] Please refer to Figures 1 to 8 As shown, an aspect of the technical solution of the present invention is applied, providing a metasurface unit, including a dielectric substrate 10 and a metal layer 20; the metal layer 20 is arranged on the dielectric substrate 10, the metal layer 20 includes an external structure 30 and an internal structure 40 arranged inside the external structure 30, the internal structure 40 includes a main ring segment 41 arranged at the center of the external structure 30 and at least three first metal segments 42 arranged at intervals along the circumferential direction of the main ring segment 41, and a second metal segment 43 is provided between each adjacent two first metal segments 42, so that the internal structure 40 forms a closed-loop structure; wherein the length of the first metal segment 42 can be adjusted.

[0031] According to one aspect of the technical solution of the present embodiment, the above-mentioned arrangement is adopted, and the dielectric substrate 10 of the equivalent circuit of the entire metasurface unit can be equivalent to an impedance, and the internal structure 40 and the external structure 30 of the metal layer 20 can be equivalent to two parallel circuits of series resonance, respectively; wherein the internal structure 40 is equivalent to an inductor, and the spacing between the main ring segment 41 of the internal structure 40 and the second metal segment 43 and the spacing between the inner circumferential walls of the main ring segment 41 are equivalent to capacitors to form a series resonance, and the spacing between the main ring segment 41 and the second metal segment 43 and the radius of the main ring segment 41 can be adjusted by adjusting the length of the first metal segment 42, thereby adjusting the relevant parameters of the internal structure 40. In this way, the external structure 30 is used to control the lower frequency band, and the internal structure 40 is used to control the higher frequency band. By replacing the dielectric substrate 10 with different relative dielectric constants or different thicknesses, or by adjusting the relevant parameters of the metal layer 20, the shielding effect of any target frequency band can be achieved, so as to achieve selective shielding of microwave signals in a specific frequency band, and has the characteristics of good shielding performance, polarization insensitivity and extremely high angular stability. The structure is miniaturized, simple and beautiful, thereby solving the problem of poor shielding performance of the frequency selective surface unit under large-angle oblique incidence in the prior art.

[0032] In this embodiment, the length of the first metal segment 42 ranges from L m Meet: 2.3mm≤L m In this way, by adjusting the length of the first metal segment 42, the parameters of the metal layer 20 related structures of the metasurface unit can be adjusted, thereby shielding microwave signals of any target frequency band.

[0033] Specifically, in two adjacent metasurface units, the preset spacing between the two external structures 30 can be adjusted; wherein the preset spacing S satisfies: 0.2mm≤S≤0.6mm. In the above setting, the external structure 30 is equivalent to an inductor, and in two adjacent external structures 30, the spacing between the two external structures 30 is equivalent to a capacitor to form another series resonance. In this way, by adjusting the length L of the first metal segment 42 respectively m The preset spacing S between two adjacent external structures 30 is used to adjust the relevant parameters of the metal layer 20, so that the metasurface unit can selectively shield microwave signals of any target frequency band, and has good shielding performance, polarization insensitivity and extremely high angle stability.

[0034] In this embodiment, the main ring segment 41 is a circular ring structure, and the radius of the main ring segment 41 is R s Satisfy: 0.4mm≤R s In this way, by adjusting the radius of the main ring segment 41 of the circular ring structure, the relevant parameters of the internal structure 40 can also be adjusted to achieve a shielding effect for any target frequency band.

[0035] like Figure 1 As shown, the second metal segment 43 includes two arc segments 430, one end of the two arc segments 430 is respectively connected to the two first metal segments 42, and the other ends of the two arc segments 430 are respectively provided with fixed segments 431 and connected to each other to form a symmetrical structure. In this way, the two adjacent first metal segments 42 and the arc segments 430 and the fixed segments 431 respectively connected to the two first metal segments 42 form a petal structure, so that the internal structure 40 is composed of a main ring segment 41 of a small circular ring and a plurality of petal structures, and forms a closed loop structure, so that by adjusting the spacing between each petal and the main ring segment 41 (i.e., the length of the first metal segment 42), the relevant parameters of the internal structure 40 can be adjusted, and the shielding of microwave signals of different target frequency bands can be achieved.

[0036] Specifically, the diameter of the arc segment 430 is L a Satisfy: 2mm≤L a ≤2.2mm.

[0037] Specifically, the fixed segment 431 is a circular structure, and the radius of the fixed segment 431 is L b Satisfy: 0.1mm≤L b In this way, by adjusting the diameters of the arc segment 430 and the fixed segment 431 respectively, petal structures with different parameters are selected to adjust the relevant parameters of the internal structure 40 .

[0038] In this embodiment, the internal structure 40 and the external structure 30 respectively control the shielding of two frequency bands. Specifically, the external structure 30 mainly controls the 2.4 GHz frequency band, and the internal structure 40 mainly controls the 5.5 GHz frequency band. Both the internal structure 40 and the external structure 30 are closed ring structures to form a resonant ring. The metal layer 20 formed by the external structure 30 and the internal structure 40 is a rotationally symmetric structure to ensure the polarization stability of the frequency selective surface to achieve a polarization-insensitive effect. Furthermore, the materials for preparing the metal layer 20 including the internal structure 40 and the external structure 30 include copper, silver, etc.

[0039] In this embodiment, there are three first metal segments 42, and a second metal segment 43 is provided between each of the first metal segments 42. It should be noted that the number of the first metal segments 42 is not limited thereto, and can be selected accordingly according to the use requirements and actual working conditions. Optionally, the number of the first metal segments 42 is four, five, six, seven, or more.

[0040] Preferably, the external structure 30 is a regular hexagonal ring structure; wherein the thickness W of each side of the external structure 30 satisfies: 0.2mm≤W≤0.6mm; the dielectric substrate 10 is a regular hexagonal plate structure, and the length L of each side of the dielectric substrate 10 satisfies: 8mm≤L≤10mm. In this way, when the hexagonal metal outer ring structure is arranged in a honeycomb shape with a hexagon as a period to form the entire frequency selective surface, the overall structure can be made more compact, and the generation of grating lobes can be effectively avoided, so that the shielding of the target frequency band will not be affected at oblique incidence, and the entire structure can have extremely high angular stability.

[0041] like Figure 1 and Figure 2 As shown, the thickness h of the dielectric substrate 10 satisfies: 2mm≤h≤4mm. In the above configuration, the metasurface unit adopts a regular hexagonal substrate, and the material for preparing the dielectric substrate 10 includes a substrate with high light transmittance such as organic glass, float glass and high borosilicate glass, and the relative dielectric constant of the substrate itself is ε r , ε r The value range is 2F / m-7F / m.

[0042] In this embodiment, the internal structure 40 composed of the main ring segment 41, the first metal segment 42 and the second metal segment 43 is an integrally formed structure. In this way, the main ring segment 41, the first metal segment 42 and the second metal segment 43 are integrally formed into the internal structure 40 of the flower-shaped structure, and the structure is rotationally symmetrical, thereby ensuring the polarization stability of the frequency selective surface, so as to achieve the effect of polarization insensitivity.

[0043] In this embodiment, the dielectric substrate 10 of the equivalent circuit of the entire metasurface unit can be equivalent to an impedance, and its resistance is:

[0044]

[0045] Among them, Z O =120π is the impedance of free space, and the structure of the entire metal layer 20 can be equivalent to two parallel circuits of series resonance. Figure 4 As shown, the external structure 30 portion of the metal layer 20 is equivalent to an inductor, and the distance between the external structures 30 of two adjacent metasurface units is equivalent to a capacitor to form one series resonance; while the internal structure 40 portion of the metal layer 20 is equivalent to an inductor, and the distance between the internal structures is equivalent to a capacitor to form another series resonance, and the external structure 30 portion controls the lower frequency band, while the internal structure 40 portion controls the higher frequency band.

[0046] According to microwave network analysis, the transmission coefficient can be expressed as:

[0047]

[0048] Where β is the phase constant of the dielectric substrate 10 along the z direction, Y M =Y O +Y i is the total admittance of the periodic metasurface, Y B is the equivalent admittance of the dielectric substrate 10. Therefore, the structure of the metasurface unit can be adjusted according to this principle, and the dielectric substrate 10 with different relative dielectric constants or different thicknesses can be replaced, and the relevant parameters of the metal layer 20 can be adjusted to achieve the shielding effect of a specific target frequency band.

[0049] In order to verify the performance of the frequency selective surface structure of one embodiment of the present invention, the shielding characteristics of the structure under different polarization modes and different incident angles are simulated and analyzed, as follows:

[0050] like Figure 5 As shown in the figure, the transmission characteristic curve of an embodiment of the present invention when a horizontally polarized electromagnetic wave is incident, it can be seen from the figure that the two resonance points of the metasurface unit are located at the 2.4GHz and 5.5GHz frequency bands, the loss can reach 50dB, and the transmission coefficient is less than -10dB in the 2.4-2.48GHz and 5.15-5.85GHz frequency bands, and both have good shielding effects. When the electromagnetic wave is obliquely incident, as the oblique incident angle increases from 0° to 80°, a good shielding effect can be shown in the Wi-Fi frequency band.

[0051] like Figure 6 As shown in the figure, the transmission characteristic curve of an embodiment of the present invention when a vertically polarized electromagnetic wave is incident, it can be seen from the figure that the two resonance points of the metasurface unit are located at the 2.4GHz and 5.5GHz frequency bands, the loss can reach 50dB, and the transmission coefficient is less than -10dB in the 2.4-2.48GHz and 5.15-5.85GHz frequency bands, and both have good shielding effects. When the electromagnetic wave is obliquely incident, as the oblique incident angle increases from 0° to 80°, a good shielding effect can be shown in the Wi-Fi frequency band.

[0052] comprehensive Figure 5 and Figure 6 It can be seen that when the metasurface unit of an embodiment of the present invention is incident with horizontally polarized waves and vertically polarized waves, as the oblique incident angle increases to 80°, the shielding performance is almost unaffected, and the Wi-Fi signal can be well shielded, thereby reducing the electromagnetic interference caused by the Wi-Fi frequency band.

[0053] like Figure 7 As shown in the figure, the transmission characteristic curve of an embodiment of the present invention when the electromagnetic wave is incident vertically, it can be seen from the figure that adjusting the L m, the shielding characteristics of the 2.4GHz band remain basically unchanged, while the resonant frequency of the 5.5GHz band shifts. Based on the principle of equivalent circuit, increasing L m , the equivalent inductance of the inner loop increases, and the 5.5GHz resonant frequency decreases.

[0054] like Figure 8 As shown, the transmission characteristic curve of another embodiment of the present invention when the electromagnetic wave is vertically incident, from Figure 8 It can be seen that by adjusting the S of the structure, the resonant frequency of the 2.4GHz band shifts, while the shielding characteristics of the 5.5GHz band remain basically unchanged. Based on the principle of equivalent circuit, increasing S increases the equivalent capacitance of the outer ring, and thus increases the 2.4GHz resonant frequency.

[0055] According to the above transmission characteristic curve after adjusting the relevant structural parameters, the adjustable characteristics of the frequency selective surface unit of the embodiment of the present invention are verified through simulation.

[0056] According to another aspect of the technical solution of the present invention, a dual-band shielding metasurface structure is provided, comprising a plurality of the metasurface units mentioned above, wherein the plurality of metasurface units are arranged in a honeycomb structure.

[0057] In the present application, the metasurface structure for dual-band Wi-Fi signal shielding can realize the shielding function of dual-band Wi-Fi signals, with a transmission loss of up to 50dB and good polarization stability, especially the angle stability of up to 80°, which can achieve shielding of Wi-Fi signals in many directions. If glass is used as the dielectric substrate 10, it can achieve the effects of Wi-Fi signal shielding, optical and other microwave frequency band transmission, and can effectively prevent electromagnetic interference caused by Wi-Fi signals in concrete buildings. The overall structure is simple, beautiful and has extremely high transparency.

[0058] Moreover, the implementation cost is low and it has high application value. Possible application scenarios in the future include military and civilian aspects. After adjusting the target frequency band, in the military aspect, it can be applied to the guidance cabin of aircraft or missiles and other flying weapons with optical and radar composite guidance to reduce the radar scattering cross section of the flying weapon and realize the stealth of the flying weapon. In the civilian aspect, if glass is used as the dielectric substrate 10, its transparent characteristics in the visible region and selective transmission or reflection in other frequency bands can be used to make environmentally friendly glass, etc., which can be applied to building materials and windshields of vehicles. It can also be used as an antenna cover for base stations or satellite antennas, which can shield signals that may cause interference while protecting the antenna from the external environment.

[0059] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0060] The metasurface unit includes a dielectric substrate 10 and a metal layer 20; the metal layer 20 is arranged on the dielectric substrate 10, the metal layer 20 includes an external structure 30 and an internal structure 40 arranged inside the external structure 30, the internal structure 40 includes a main ring segment 41 arranged at the center of the external structure 30 and at least three first metal segments 42 arranged at intervals in the circumferential direction of the main ring segment 41, and a second metal segment 43 is provided between each adjacent two first metal segments 42, so that the internal structure 40 forms a closed-loop structure; wherein the relevant parameters of the metal layer can be adjusted. With the above arrangement, the dielectric substrate 10 of the equivalent circuit of the entire metasurface unit can be equivalent to an impedance, and the internal structure 40 and the external structure 30 of the metal layer 20 can be equivalent to two parallel circuits of series resonance, respectively; wherein the internal structure 40 is equivalent to an inductor, and the spacing between the main ring segment 41 of the internal structure 40 and the second metal segment 43 and the spacing between the inner circumferential walls of the main ring segment 41 are equivalent to capacitors to form a series resonance, and the spacing between the main ring segment 41 and the second metal segment 43 and the radius of the main ring segment 41 can be adjusted by adjusting the length of the first metal segment 42, so as to adjust the relevant parameters of the internal structure 40. In this way, the external structure 30 is used to control the lower frequency band, and the internal structure 40 is used to control the higher frequency band. By replacing the dielectric substrate 10 with different relative dielectric constants or different thicknesses, or by adjusting the relevant parameters of the metal layer 20, the shielding effect of any target frequency band can be achieved, so as to achieve selective shielding of microwave signals in a specific frequency band, and has the characteristics of good shielding performance, polarization insensitivity and extremely high angular stability. The structure is miniaturized, simple and beautiful, thereby solving the problem of poor shielding performance of the frequency selective surface unit under large-angle oblique incidence in the prior art.

[0061] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0062] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0063] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0064] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0065] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A metasurface unit, characterized in that: include: A dielectric substrate (10); A metal layer (20) is arranged on the dielectric substrate (10), the metal layer (20) comprising an external structure (30) and an internal structure (40) arranged inside the external structure (30), the internal structure (40) comprising a main ring segment (41) arranged at the center of the external structure (30) and at least three first metal segments (42) arranged at intervals along the circumferential direction of the main ring segment (41), and a second metal segment (43) is arranged between two adjacent first metal segments (42), so that the internal structure (40) forms a closed loop structure; The length of the first metal segment (42) is adjustable.

2. The metasurface unit according to claim 1, characterized in that: The length of the first metal segment (42) has a range of L m Meet: 2.3mm≤L m ≤2.5mm.

3. The metasurface unit according to claim 1, characterized in that: In two adjacent super-surface units, the preset spacing between the two external structures (30) can be adjusted; wherein the preset spacing S satisfies: 0.2mm≤S≤0.6mm.

4. The metasurface unit according to claim 1, characterized in that: The main ring segment (41) is a circular ring structure, and the radius of the main ring segment (41) is R s Satisfy: 0.4mm≤R s ≤1mm.

5. The metasurface unit according to claim 1, characterized in that: The second metal segment (43) comprises two circular arc segments (430), one end of the two circular arc segments (430) is respectively connected to the two first metal segments (42), and the other ends of the two circular arc segments (430) are respectively provided with fixed segments (431) and are connected to each other to form a symmetrical structure.

6. The metasurface unit according to claim 5, characterized in that: The diameter of the arc segment (430) is L a Satisfy: 2mm≤L a ≤2.2mm; and / or, The fixed segment (431) is a circular structure, and the radius of the fixed segment (431) is L b Satisfy: 0.1mm≤L b ≤1mm.

7. The metasurface unit according to claim 1, characterized in that: The external structure (30) is a regular hexagonal ring structure; wherein the thickness W of each side of the external structure (30) satisfies: 0.2 mm ≤ W ≤ 0.6 mm; and / or, The dielectric substrate (10) is a regular hexagonal plate-shaped structure, and the length L of each side of the dielectric substrate (10) satisfies: 8 mm ≤ L ≤ 10 mm.

8. The metasurface unit according to claim 1, characterized in that: The thickness h of the dielectric substrate (10) satisfies: 2 mm ≤ h ≤ 4 mm.

9. The metasurface unit according to claim 1, characterized in that: The main ring segment (41), the first metal segment (42) and the second metal segment (43) are an integrally formed structure.

10. A dual-band shielding metasurface structure, characterized in that: It comprises a plurality of the super surface units according to any one of claims 1 to 9, wherein the plurality of the super surface units are arranged in a honeycomb structure.

Images