Electromagnetic shielding structure based on broadband high-suppression three-dimensional metasurface
By designing a three-dimensional structure with nine layers of metal combined with vertical surfaces, the problems of insufficient passband width and insufficient stopband suppression of existing electromagnetic shielding structures are solved, achieving a wide-band electromagnetic shielding effect with low insertion loss and high stopband suppression, which is suitable for complex electromagnetic environments.
Patent Information
- Application Number
- CN202511540903.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-27
- Publication Date
- 2026-01-20
AI Technical Summary
Existing electromagnetic shielding structures have insufficient passband width, high in-band insertion loss, inadequate stopband suppression, and poor angular stability, which limits their application in complex electromagnetic environments.
The design employs a three-dimensional structure with nine layers of metal combined with vertical surfaces, including two outer antenna layers, one middle antenna layer, and two vertical antenna layers. New resonant modes are generated through interlayer coupling and cross-coupling, which improves stopband suppression and maintains wide passband performance.
It achieves low insertion loss and high stopband suppression in broadband, has good angular stability, and is suitable for electromagnetic interference shielding in complex electromagnetic environments.
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Figure CN121367072A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the field of electromagnetic field and microwave technology, and particularly relates to an electromagnetic shielding structure based on a broadband high-suppression three-dimensional super surface. BACKGROUND
[0002] With the rapid development of the communication technology industry, the communication electromagnetic environment is increasingly complex, which poses a major threat to the normal operation of communication equipment. Therefore, the demand for electromagnetic wave control becomes crucial.
[0003] As a spatial filter, the super surface can interact with spatial electromagnetic waves for selective filtering based on frequency and polarization mode, and is therefore widely applied in various fields such as radar dome design, antenna design, electromagnetic interference and electromagnetic shielding. The new generation of communication equipment needs to support a wider passband to achieve full coverage of communication frequencies, and at the same time needs to provide better selectivity to shield the interference of other equipment while ensuring the normal transmission of communication signals. For this reason, it requires the super surface to not only achieve wide passband performance, but also provide high stopband suppression. In addition, since the transmitting antenna and the receiving antenna are not necessarily directly opposite during the communication process, the super surface also needs to have good angle stability.
[0004] The existing electromagnetic shielding structure has a series of problems such as insufficiently wide passband, excessively large in-band insertion loss, insufficient stopband suppression and poor angle stability, which seriously limits the application of the electromagnetic shielding structure in complex electromagnetic environments. SUMMARY
[0005] In view of the problem of how to improve the passband width, reduce the insertion loss of the passband, improve the stopband suppression and the angle stability, so as to meet the interference shielding requirements in complex electromagnetic environments, an electromagnetic shielding structure based on a broadband high-suppression three-dimensional super surface is proposed. Through the design of a three-dimensional structure of nine layers of metal combined with vertical surfaces, the electromagnetic shielding structure has a relatively wide passband while maintaining a relatively low passband insertion loss, and has a relatively high stopband suppression, roll-off speed and angle stability.
[0006] The technical scheme adopted by the application is as follows: The electromagnetic shielding structure mainly comprises a plurality of periodic unit structures that are the same and closely arranged in the form of a planar array, the periodic unit structure comprises two outer antenna layers, one middle antenna layer and two vertical antenna layers, the two outer antenna layers are symmetrically distributed on the two sides of the middle antenna layer, and one vertical antenna layer is arranged between each outer antenna layer and the middle antenna layer, the two vertical antenna layers are symmetrically distributed about the middle antenna layer, and each vertical antenna layer is connected with the middle antenna layer and the outer antenna layer adjacent thereto; the electromagnetic wave of the free space is selectively filtered by the electromagnetic shielding structure and then outputted as an electromagnetic wave of a required working frequency band.
[0007] The outer antenna layer comprises, from top to bottom, a first layer of large rectangular metal patches, a first layer of dielectric plates, a first layer of small rectangular metal patches, a second layer of front curved metal structures, a second layer of dielectric plates, and a second layer of back curved metal strips; the upper and lower surfaces of the first layer of dielectric plates are respectively paved with the first layer of large rectangular metal patches and the first layer of small rectangular metal patches, the upper and lower surfaces of the second layer of dielectric plates are respectively paved with the second layer of front curved metal structures and the second layer of back curved metal strips, mounting holes are respectively formed in the four corners of the second layer of dielectric plates, the vertical antenna layer is located on the side of the second layer of back curved metal strips away from the second layer of dielectric plates, the upper end of the vertical antenna layer is embedded in the mounting hole of the second layer of dielectric plates and extends out of the mounting hole to be connected to the first layer of dielectric plates, and the second layer of front curved metal structures is electrically connected to the upper end of the vertical antenna layer.
[0008] The middle antenna layer comprises a third layer of slots and a third layer of dielectric plates, the third layer of slots is paved on the surface of one side of the third layer of dielectric plates, and the two sides of the third layer of dielectric plates are respectively connected to the vertical antenna layers on the two sides; The third layer of slots comprises a cross-shaped metal patch located at the center of the third layer of dielectric plates and four square corner patches respectively located at the four corners of the third layer of dielectric plates, all the square corner patches are spaced apart from the cross-shaped metal patch, and each square corner patch has two straight angles that overlap the third layer of dielectric plates, and a rectangular notch is arranged at each of the two straight angles adjacent to the overlapping straight angles.
[0009] The vertical antenna layer comprises four vertical dielectric plates arranged around the outer antenna layer and four vertical metal surfaces respectively arranged on the vertical dielectric plates, each two adjacent vertical dielectric plates are fixedly connected, one side of the vertical dielectric plate is provided with a protrusion as the upper end of the vertical dielectric plate, and the upper end of each vertical dielectric plate is respectively embedded in the mounting hole of the second layer of dielectric plates and extends out of the mounting hole to be connected to the first layer of dielectric plates; Each vertical dielectric plate has a vertical metal surface paved on the side wall facing the outer antenna layer, each vertical metal surface comprises a main metal surface located in the middle and two side metal surfaces respectively located on the two sides of the main metal surface, the two side metal surfaces are spaced apart from the main metal surface, and one end of the main metal surface extends out along the upper end of the vertical dielectric plate to be electrically connected to the second layer of front curved metal structures.
[0010] The first layer of large rectangular metal patches are mainly composed of a plurality of square metal patches arranged in a planar array.
[0011] The first layer of small rectangular metal patches are mainly composed of a plurality of repeating units arranged in a planar array, each repeating unit comprises two square metal patches located at opposite corners of the repeating unit, and the two square metal patches are independent of each other.
[0012] The second layer medium plate is provided with a via hole beside each of the two opposite mounting holes, and the second layer front curved metal structure comprises four connecting metal patches arranged beside the four mounting holes of the second layer medium plate and a second layer front curved metal strip, two ends of the second layer front curved metal strip are connected with the two connecting metal patches beside the non-via holes respectively, and the second layer front curved metal strip is in a snake shape.
[0013] Two ends of the second layer back curved metal strip are connected to the connecting metal patches beside the via holes through the two via holes, and the second layer back curved metal strip is in a snake shape.
[0014] The first layer medium plate, the second layer medium plate and the third layer medium plate all adopt F4B plate materials with a dielectric constant of 3 and a dielectric loss tangent of 0.001.
[0015] The electromagnetic shielding structure is applied to modern communication, radar and military communication of 5G.
[0016] The present application has the beneficial effects of: The first layer, the third layer and the fifth layer of the present application are coupled with each other to provide a wideband low-insertion-loss passband for the three-dimensional metasurface, in the case of normal incidence of spatial electromagnetic waves, the average insertion loss of TE and TM modes in the passband frequency range of 1.5-3.7GHz is less than 0.43dB, and the passband width reaches 84.6%; in the case of 60-degree oblique incidence of spatial electromagnetic waves, the average insertion loss of TE mode in the passband frequency range of 1.5-3.7GHz is less than 0.95dB, and the average insertion loss of TM mode in the passband frequency range of 1.5-3.7GHz is less than 0.50dB.
[0017] The four meandering metal strips and the vertical metal surface provide a high-rejection stopband for the three-dimensional metasurface, in the case of normal incidence of spatial electromagnetic waves, the stopband rejection of TE and TM modes in the stopband frequency range of 0.69-1.19GHz is greater than 10dB, and the stopband rejection of the high-frequency stopband at 4GHz is greater than 10dB; in the case of 60-degree oblique incidence of spatial electromagnetic waves, the stopband rejection of TE mode in the stopband frequency range of 0.68-1.4GHz is greater than 10dB, and the stopband rejection of the high-frequency stopband at 4GHz is greater than 10dB; the stopband rejection of TM mode in the stopband frequency range of 0.7-1.11GHz is greater than 10dB, and the stopband rejection of the high-frequency stopband at 4GHz is greater than 10dB.
[0018] The application improves the traditional two-dimensional structure, introduces vertical structure to increase the cross coupling between layers on the basis of maintaining the performance of wide passband and low insertion loss, generates new resonance mode, effectively improves the stopband rejection of electromagnetic shielding structure, and realizes the miniaturization design of the structure by the new freedom brought by the vertical structure. Although the super surface of the application has vertical structure, it can still be applied to the traditional PCB process for processing and implementation. BRIEF DESCRIPTION OF DRAWINGS
[0019] Figure 1 is a three-dimensional structure diagram of the super surface of the embodiment of the application.
[0020] Figure 2 is a three-dimensional structure diagram of the periodic unit structure in the application.
[0021] Figure 3 is a front view of the periodic unit structure in the application.
[0022] Figure 4 is a structure view of the large rectangular metal patch in the application.
[0023] Figure 5 is a structure view of the small rectangular metal patch in the application.
[0024] Figure 6 is a structure view of the curved metal strip one in the application.
[0025] Figure 7 is a structure view of the curved metal strip two in the application.
[0026] Figure 8 is a structure view of the slit in the application.
[0027] Figure 9 is a structure view of the vertical metal surface in the application.
[0028] Figure 10 is a transmission characteristic curve of the three-dimensional super surface in the application.
[0029] Figure 11 is an influence curve of the electromagnetic wave incident angle on the three-dimensional super surface in the application under the TE mode.
[0030] Figure 12 is an influence curve of the electromagnetic wave incident angle on the three-dimensional super surface in the application under the TM mode.
[0031] In the figure: 1, the first layer of large rectangular metal patch, 2, the first layer of dielectric plate, 3, the first layer of small rectangular metal patch, 4, the second layer of front curved metal structure, 5, the second layer of dielectric plate, 6, the second layer of back curved metal strip, 7, the vertical dielectric plate, 8, the vertical metal surface, 9, the third layer of slot, 10, the third layer of dielectric plate. DETAILED DESCRIPTION
[0032] In order to explain the technical scheme disclosed by the present application in detail, further elaboration will be made below in combination with the drawings of the specification and specific embodiments.
[0033] As shown in Figure 1 and Figure 2 , the present embodiment mainly consists of a plurality of identical and closely arranged periodic unit structures in the form of a planar array, the periodic unit structure including two layers of outer antenna layers, one layer of intermediate antenna layer and two layers of vertical antenna layers, the two layers of outer antenna layers being symmetrically distributed on the two sides of the intermediate antenna layer, and one layer of vertical antenna layer being provided between each layer of outer antenna layer and the intermediate antenna layer, the two layers of vertical antenna layers being symmetrically distributed about the intermediate antenna layer, and each layer of vertical antenna layer being fixedly connected with the intermediate antenna layer and the outer antenna layer adjacent to itself; the electromagnetic wave of the free space is selectively filtered by the electromagnetic shielding structure and then outputted as electromagnetic wave of the required working frequency band.
[0034] The number of periodic unit structures can be selected between 15x15 and 40x40 according to actual use.
[0035] As shown in Figure 2 and Figure 3 , the outer antenna layer includes the first layer of large rectangular metal patch 1, the first layer of dielectric plate 2, the first layer of small rectangular metal patch 3, the second layer of front curved metal structure 4, the second layer of dielectric plate 5 and the second layer of back curved metal strip 6 which are sequentially arranged from top to bottom; the upper and lower surfaces of the first layer of dielectric plate 2 are respectively paved with the first layer of large rectangular metal patch 1 and the first layer of small rectangular metal patch 3, the upper and lower surfaces of the second layer of dielectric plate 5 are respectively paved with the second layer of front curved metal structure 4 and the second layer of back curved metal strip 6, mounting holes are respectively provided at the four corners of the second layer of dielectric plate 5, the vertical antenna layer is located on the side of the second layer of back curved metal strip 6 away from the second layer of dielectric plate 5, the upper end of the vertical antenna layer is embedded in the mounting hole of the second layer of dielectric plate 5 and extends out of the mounting hole to be connected to the first layer of dielectric plate 2, and the second layer of front curved metal structure 4 is electrically connected with the upper end of the vertical antenna layer.
[0036] The intermediate antenna layer includes the third layer of slot 9 and the third layer of dielectric plate 10, the third layer of slot 9 is paved on the surface of one side of the third layer of dielectric plate 10, and the two sides of the third layer of dielectric plate 10 are respectively connected with the vertical antenna layers on the two sides; As shown in Figure 8As shown, the third layer gap 9 includes a cross-shaped metal patch in the center of the third layer dielectric plate 10 and four square corner patches respectively at the four corners of the third layer dielectric plate 10. All the square corner patches are spaced apart from the cross-shaped metal patch, i.e. there is a gap between each square corner patch and the cross-shaped metal patch. Each square corner patch has two coincident right angles with the third layer dielectric plate 10, and a rectangular notch is arranged at each of the two coincident right angles. One long side of the rectangular notch coincides with the edge of the third layer dielectric plate 10.
[0037] The vertical antenna layer includes four vertical dielectric plates 7 arranged around the outer antenna layer and four vertical metal surfaces 8 respectively arranged on the vertical dielectric plates 7. Each two adjacent vertical dielectric plates 7 are fixedly connected. One side of each vertical dielectric plate 7 is provided with a protrusion as the upper end of the vertical dielectric plate 7. The upper end of each vertical dielectric plate 7 is respectively embedded in the mounting hole of the second layer dielectric plate 5 and extends out of the mounting hole to be connected to the first layer dielectric plate 2. Each vertical dielectric plate 7 is provided with a vertical metal surface 8 on the side wall facing the outer antenna layer. Each vertical metal surface 8 includes a main metal surface 8a in the middle and two side metal surfaces 8b respectively arranged on both sides of the main metal surface 8a. The two side metal surfaces 8b are spaced apart from the main metal surface 8a. One end of the main metal surface 8a extends out of the upper end of the vertical dielectric plate 7 and is electrically connected to the second layer front curved metal structure 4.
[0038] As shown in FIG. 1, Figure 4 The first layer large rectangular metal patch 1 is mainly composed of a plurality of square metal patches arranged in a planar array. Figure 5 As shown in FIG. 1,
[0039] As shown in FIG. 1, Figure 6 and Figure 7 As shown in FIG. 1, the second layer dielectric plate 5 is provided with a via hole beside each of the two opposite mounting holes. The second layer front curved metal structure 4 includes four connection metal patches respectively arranged beside the four mounting holes of the second layer dielectric plate 5 and a second layer front curved metal strip. The two ends of the second layer front curved metal strip are respectively connected to the two connection metal patches beside the non-via hole. The second layer front curved metal strip is in a serpentine shape.
[0040] The two ends of the second layer back curved metal strip 6 are respectively connected to the connection metal patches beside the via holes through the two via holes. The second layer back curved metal strip 6 is in a serpentine shape.
[0041] The first layer dielectric plate 2, the second layer dielectric plate 5 and the third layer dielectric plate 10 are all F4B plates with a dielectric constant of 3 and a dielectric loss tangent of 0.001.
[0042] The electromagnetic shielding structure is applied to modern communication, radar and military communication of 5G.
[0043] In the case of normal incidence of spatial electromagnetic waves, the average insertion loss of TE and TM modes in the passband frequency range of 1.5-3.7 GHz is less than 0.43 dB, the passband width reaches 84.6%, the stopband suppression degree in the stopband frequency range of 0.69-1.19 GHz is greater than 10 dB, and the stopband suppression degree of the high-frequency stopband at 4 GHz is greater than 10 dB.
[0044] In the case of 60-degree oblique incidence of spatial electromagnetic waves, the average insertion loss of TE mode in the passband frequency range of 1.5-3.7 GHz is less than 0.95 dB, the stopband suppression degree in the stopband frequency range of 0.68-1.4 GHz is greater than 10 dB, and the stopband suppression degree of the high-frequency stopband at 4 GHz is greater than 10 dB; the average insertion loss of TM mode in the passband frequency range of 1.5-3.7 GHz is less than 0.50 dB, the stopband suppression degree in the stopband frequency range of 0.7-1.11 GHz is greater than 10 dB, and the stopband suppression degree of the high-frequency stopband at 4 GHz is greater than 10 dB.
[0045] In the embodiment, the five-layer planar dielectric plates all adopt F4B plates with a thickness of 0.25 mm, a dielectric constant of 3 and a dielectric loss tangent of 0.001. The two-layer vertical dielectric plates all adopt F4B plates with a thickness of 2.00 mm, a dielectric constant of 3 and a dielectric loss tangent of 0.001.
[0046] As shown in Figure 4 , the large rectangular metal patch structure parameter of the application is: P = 18 mm, D = 4.5 mm.
[0047] As shown in Figure 5 , the small rectangular metal patch structure parameter of the application is: M = 2.8 mm.
[0048] As shown in Figure 6 , the first bending metal strip structure parameter of the application is: O = 1 mm, L1 = 2.6 mm, L2 = 0.2 mm, L3 = 1.4 mm.
[0049] As shown in Figure 7 , the second bending metal strip structure parameter of the application is: R = 0.15 mm.
[0050] As shown in Figure 8As shown, the slit structure parameters of the application are: K=0.2 mm, X1=8.1 mm, X2=3 mm, X3=0.8 mm.
[0051] As shown, the vertical medium plate of the application is provided with the same vertical metal surface on both sides. Figure 9 As shown, the vertical medium plate of the application is provided with the same vertical metal surface on both sides.
[0052] The working principle of the three-dimensional metasurface of the application is as follows: a large capacitance is generated between the large rectangular metal patch and the small rectangular metal patch under the action of electromagnetic waves due to interlayer coupling; since the first layer and the fifth layer structure are the same, they can be equivalent to two capacitors in parallel; The slit between the metal patch and the metal strip in the third layer slit also generates a capacitance, and the metal strip itself generates a large current under the action of electromagnetic waves, so it can be regarded as an inductor; 3. Overall, it can be regarded as three capacitors in parallel with an inductor, so a wide passband covering 1.5-3.7 GHz is generated; 4. The second layer curved metal strip, the fourth layer curved metal strip and the upper and lower layer vertical metal surface are respectively electrically connected to form an LC series resonant circuit to generate a zero point, thereby improving the suppression degree in the stopband frequency range of 0.69-1.19 GHz.
[0053] In order to meet the application requirements of the new generation of communication systems, the commonly used communication frequency bands in actual life are selected for design, and finally the working frequency band design of the three-dimensional metasurface proposed by the application is 1.5-3.7 GHz. Figure 10 The transmission characteristic curve of the three-dimensional metasurface proposed by the application under the condition of spatial electromagnetic wave normal incidence can be seen that the average insertion loss in the passband frequency range of 1.5-3.7 GHz is less than 0.43 dB, the passband width reaches 84.6%, the stopband suppression degree in the stopband frequency range of 0.69-1.19 GHz is greater than 10 dB, and the stopband suppression degree of the high frequency stopband at 4 GHz is greater than 10 dB.
[0054] Figure 11 The influence curve of different electromagnetic wave incident angles on the three-dimensional metasurface in the application under the TE mode can be seen that with the increase of the angle, the suppression degree in the stopband frequency range increases, and the insertion loss in the passband frequency range of 1.5-3.7 GHz increases. Among them, under the condition of spatial electromagnetic wave 60-degree oblique incidence, the average insertion loss of the TE mode in the passband frequency range of 1.5-3.7 GHz is less than 0.95 dB, the stopband suppression degree in the stopband frequency range of 0.68-1.4 GHz is greater than 10 dB, and the stopband suppression degree of the high frequency stopband at 4 GHz is greater than 10 dB.
[0055] Figure 12 The influence curve of different electromagnetic wave incident angles on the three-dimensional metasurface in the TM mode can be seen from the three-dimensional metasurface provided in the application, and it can be seen that the suppression degree in the stopband frequency range remains basically unchanged as the angle increases, the passband is widened to 1.5-3.7 GHz, and the insertion loss in the frequency range remains basically unchanged. Among them, in the case of 60-degree oblique incidence of spatial electromagnetic waves, the average insertion loss of the TM mode in the passband frequency range of 1.5-3.7 GHz is less than 0.50 dB, the stopband suppression degree in the stopband frequency range of 0.7-1.11 GHz is greater than 10 dB, and the stopband suppression degree of the high-frequency stopband at 4 GHz is greater than 10 dB.
[0056] The application provides an electromagnetic shielding structure based on a wideband high-suppression three-dimensional metasurface, which realizes that in the case of normal incidence of spatial electromagnetic waves, the average insertion loss of the TE and TM modes in the passband frequency range of 1.5-3.7 GHz is less than 0.43 dB, the passband width reaches 84.6%, the stopband suppression degree in the stopband frequency range of 0.69-1.19 GHz is greater than 10 dB, and the stopband suppression degree of the high-frequency stopband at 4 GHz is greater than 10 dB. In the case of 60-degree oblique incidence of spatial electromagnetic waves, the average insertion loss of the TE mode in the passband frequency range of 1.5-3.7 GHz is less than 0.95 dB, the stopband suppression degree in the stopband frequency range of 0.68-1.4 GHz is greater than 10 dB, and the stopband suppression degree of the high-frequency stopband at 4 GHz is greater than 10 dB; the average insertion loss of the TM mode in the passband frequency range of 1.5-3.7 GHz is less than 0.50 dB, the stopband suppression degree in the stopband frequency range of 0.7-1.11 GHz is greater than 10 dB, and the stopband suppression degree of the high-frequency stopband at 4 GHz is greater than 10 dB. Compared with the existing metasurface structure, the application has the advantages of wideband pass, low insertion loss in the passband, high stopband suppression degree, rapid roll-off, good angle stability and the like, and therefore has important application value in the field of mobile communication such as shielding of electromagnetic interference in a complex electromagnetic environment.
[0057] The above is only one preferred embodiment of the application and does not constitute any limitation on the application. Obviously, for those skilled in the art, after understanding the content and principles of the application, various modifications and changes in form and details can be made without departing from the principles and structures of the application, but these modifications and changes based on the idea of the application are still within the protection scope of the claims of the application.
Claims
1. An electromagnetic shielding structure based on a broadband high-suppression three-dimensional metasurface, characterized in that: The electromagnetic shielding structure mainly consists of multiple identical periodic unit structures arranged closely in a planar array. Each periodic unit structure includes two outer antenna layers, one middle antenna layer, and two vertical antenna layers. The two outer antenna layers are symmetrically distributed on both sides of the middle antenna layer, and a vertical antenna layer is provided between each outer antenna layer and the middle antenna layer. The two vertical antenna layers are symmetrically distributed about the middle antenna layer, and each vertical antenna layer is connected to the middle antenna layer and its adjacent outer antenna layer. Electromagnetic waves in free space are selectively filtered by the electromagnetic shielding structure and then output as electromagnetic waves in the required operating frequency band.
2. The electromagnetic shielding structure based on a broadband high-suppression three-dimensional metasurface according to claim 1, characterized in that: The outer antenna layer includes, from top to bottom, a first layer of large rectangular metal patch (1), a first layer of dielectric substrate (2), a first layer of small rectangular metal patch (3), a second layer of front-curved metal structure (4), a second layer of dielectric substrate (5), and a second layer of back-curved metal strip (6). The first layer of large rectangular metal patch (1) and the first layer of small rectangular metal patch (3) are respectively laid on the upper and lower surfaces of the first layer of dielectric substrate (2). The second layer of front-curved metal structure (4) and the second layer of back-curved metal strip (6) are respectively laid on the upper and lower surfaces of the second layer of dielectric substrate (5). Mounting holes are opened around the second layer of dielectric substrate (5). The vertical antenna layer is located on the side of the second layer of back-curved metal strip (6) away from the second layer of dielectric substrate (5). The upper end of the vertical antenna layer is embedded in the mounting hole of the second layer of dielectric substrate (5) and extends out of the mounting hole to connect to the first layer of dielectric substrate (2). The second layer of front-curved metal structure (4) is electrically connected to the upper end of the vertical antenna layer.
3. The electromagnetic shielding structure based on a broadband high-suppression three-dimensional metasurface according to claim 1, characterized in that: The middle antenna layer includes a third layer slot (9) and a third layer dielectric substrate (10). The third layer slot (9) is laid on the surface of one side of the third layer dielectric substrate (10). The two sides of the third layer dielectric substrate (10) are respectively connected to the vertical antenna layers on both sides. The third layer gap (9) includes a cross-shaped metal patch located at the center of the third layer medium plate (10) and four square corner pieces located at the four corners of the third layer medium plate (10). All the square corner pieces are spaced apart from the cross-shaped metal patch. Each square corner piece has a right angle that coincides with the third layer medium plate (10), and there is a rectangular notch at the two right angles adjacent to the coincident right angle.
4. The electromagnetic shielding structure based on a broadband high-suppression three-dimensional metasurface according to claim 1, characterized in that: The vertical antenna layer includes four vertical dielectric plates (7) arranged around the outer antenna layer and four vertical metal surfaces (8) respectively arranged on each vertical dielectric plate (7). Each pair of adjacent vertical dielectric plates (7) are fixedly connected. One side of each vertical dielectric plate (7) is provided with a protrusion as the upper end of the vertical dielectric plate (7). The upper end of each vertical dielectric plate (7) is respectively embedded in the mounting hole of the second layer dielectric plate (5) and extends out of the mounting hole to connect to the first layer dielectric plate (2). Each vertical dielectric plate (7) has a vertical metal surface (8) laid on the side wall facing the outer antenna layer. Each vertical metal surface (8) includes a main metal surface (8a) in the middle and two side metal surfaces (8b) on both sides of the main metal surface. The two side metal surfaces (8b) are distributed at intervals with the main metal surface (8a). One end of the main metal surface (8a) extends along the upper end of the vertical dielectric plate (7) and is electrically connected to the second front curved metal structure (4).
5. The electromagnetic shielding structure based on a broadband high-suppression three-dimensional metasurface according to claim 1, characterized in that: The first layer of large rectangular metal patches (1) is mainly composed of multiple square metal patches arranged at intervals in a planar array.
6. The electromagnetic shielding structure based on a broadband high-suppression three-dimensional metasurface according to claim 1, characterized in that: The first layer of small rectangular metal patches (3) is mainly composed of multiple repeating units arranged in a planar array. Each repeating unit includes two square metal patches located at opposite corners of the repeating unit. The two square metal patches are independent of each other.
7. The electromagnetic shielding structure based on a broadband high-suppression three-dimensional metasurface according to claim 1, characterized in that: The second layer medium plate (5) has a via hole next to each of the two opposite mounting holes. The second layer front curved metal structure (4) includes four connecting metal patches respectively set next to the four mounting holes of the second layer medium plate (5) and a second layer front curved metal strip. The two ends of the second layer front curved metal strip are respectively connected to the two connecting metal patches next to the non-via holes. The second layer front curved metal strip is serpentine.
8. The electromagnetic shielding structure based on a broadband high-suppression three-dimensional metasurface according to claim 7, characterized in that: The two ends of the second layer back-curved metal strip (6) are connected to the connecting metal patch next to the via through two vias respectively. The second layer back-curved metal strip (6) is serpentine.
9. The electromagnetic shielding structure based on a broadband high-suppression three-dimensional metasurface according to claim 1, characterized in that: The first dielectric substrate (2), the second dielectric substrate (5) and the third dielectric substrate (10) are all made of F4B material with a dielectric constant of 3 and a dielectric loss tangent of 0.
001.
10. The application of the electromagnetic shielding structure based on a broadband high-suppression three-dimensional metasurface as described in any one of claims 1 to 9, characterized in that: The electromagnetic shielding structure is used in modern 5G communications, radar, and military communications.