Anti-interference all-metal dual-polarization broadband multifunctional metasurface structure for C-band satellite communication

Abstract

The invention belongs to the technical field of satellite communication, and particularly provides an anti-interference all-metal dual-polarization broadband multifunctional metasurface structure for C-band satellite communication, which is used for meeting the interference suppression requirements of high-reliability communication systems such as a satellite ground station and an airborne / shipborne communication terminal. According to the invention, a periodic array formed by multiple layers of improved Jerusalem-like cross slot units is adopted, and through an innovative interlayer coupling mechanism and electromagnetic resonance characteristic optimization design, low profile is maintained, and low-loss transmission performance superior to-1dB in TE and TM dual-polarization modes is realized at the same time. Particularly, the structure shows a stable broadband wave-transparent characteristic during small-angle incidence and shows remarkable angle selectivity during large-angle incidence, and the interference rejection ratio can reach 15dB or above. In conclusion, the invention provides a metasurface structure with broadband performance, dual-polarization compatibility and angle selectivity, and the metasurface structure can effectively suppress the influence of same-frequency interference sources of a 5G base station and the like.

Description

Technical Field

[0001] The present invention belongs to the field of satellite communication technology, and specifically provides an all-metal dual-polarization broadband multifunctional metasurface structure for anti-interference of C-band satellite communications, which is particularly suitable for an integrated electromagnetic metasurface design with both frequency selection and spatial beam control functions. Background Art

[0002] With the large-scale commercial deployment of fifth-generation mobile communications (5G) technology, the 3.4-3.6 GHz frequency band has become one of the primary operating frequency bands for 5G networks. However, this band significantly overlaps with the satellite communications C-band (3.4-4.2 GHz), causing 5G base station signals to significantly interfere with satellite ground station receiving systems. Particularly in densely populated areas such as cities, out-of-band radiation and adjacent channel leakage power from 5G signals can degrade the signal-to-noise ratio (SNR) of satellite receivers by over 10 dB, severely impacting communication quality. While traditional solutions (such as adding bandpass filters) can partially suppress out-of-band interference, they cannot effectively address the mutual interference between 5G signals and satellite signals within the same frequency band and also reduce the system's effective operating bandwidth. Since C-band satellite communications typically operate on high-orbit satellites, high-gain antennas are required for communication. Consequently, high-gain parabolic antennas are widely used. However, due to the extremely low sidelobes of parabolic antennas, traditional angle-selective surfaces often have little or no effect when used in conjunction with parabolic antennas.

[0003] Currently, satellite ground stations primarily use two technologies, adaptive filtering and spatial beam nulling, to combat 5G interference. While adaptive filters can dynamically suppress interference spectrum, they inevitably attenuate useful signals, resulting in a more than 15% drop in system throughput. Phased array antenna systems can create radiation nulls in the direction of interference through beam nulling, but when faced with multiple 5G base station interference sources, system complexity increases significantly, and real-time performance becomes difficult to guarantee. Furthermore, most existing metasurface filters only support a single polarization mode and cannot meet the requirements of dual-polarization satellite communication systems. While filters with multi-layer dielectric structures can achieve good frequency selectivity, they suffer from high insertion loss (typically exceeding 2dB) and limited power capacity, making them difficult to meet the requirements of high-sensitivity satellite communication systems.

[0004] In view of the shortcomings of existing technologies, it is urgent to develop a new anti-interference solution; the ideal technical solution should be able to achieve a high suppression ratio (greater than 25dB) in the 3.4-3.6GHz frequency band while ensuring low-loss transmission (insertion loss less than 0.5dB) in the 3.7-4.2GHz satellite communication frequency band; and the technical solution is required to have dual-polarization processing capabilities, which can effectively distinguish and isolate signals with different polarization modes. At the same time, it is necessary to carry out targeted design for parabolic antennas so that they can still play a role for parabolic antennas with ultra-low sidelobes; in addition, through the careful design of metasurface units, spatial filtering of interference in specific directions can be achieved without increasing the complexity of the system, thereby forming a frequency-space joint anti-interference mechanism. Based on this, the present invention provides an all-metal dual-polarization broadband multifunctional metasurface structure for C-band satellite communication anti-interference. Summary of the Invention

[0005] The purpose of the present invention is to provide an all-metal dual-polarization broadband multifunctional metasurface structure for C-band satellite communication anti-interference, to meet the interference suppression requirements of high-reliability communication systems such as satellite ground stations, airborne / shipborne communication terminals; the present invention adopts a periodic array composed of multiple layers of improved Jerusalem cross slot units, through innovative interlayer coupling mechanism and electromagnetic resonance characteristic optimization design, while performing targeted optimization for parabolic antennas, to achieve excellent dual-polarization working performance and broadband response characteristics within the 3.4GHz-3.6GHz operating frequency band. Specifically, the metasurface structure achieves low-loss transmission performance of better than -1dB in both TE and TM dual-polarization modes while maintaining a low profile (<2λ) through carefully designed cross slot unit geometric parameters and multi-layer cascade structure. In particular, the structure exhibits stable broadband transmission characteristics (insertion loss <1dB) at low angles of incidence (0°~18°), and exhibits significant angular selectivity at large angles of incidence (28°~80°), with an interference suppression ratio of more than 15dB. Furthermore, thanks to its all-metal integrated structural design, the metasurface has high power capacity and excellent thermal stability. Using low-cost CNC machining processes, the manufacturing cost of a single device can be controlled within 60% of that of a traditional dielectric substrate filter. In summary, the present invention proposes a metasurface structure that combines broadband performance, dual-polarization compatibility, and angular selectivity. This structure can effectively suppress the influence of co-frequency interference sources such as 5G base stations, and is particularly suitable for interference suppression scenarios in high-reliability communication systems such as satellite ground stations and airborne / shipborne communication terminals.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A full-metal dual-polarization broadband multifunctional metasurface structure for anti-interference in C-band satellite communications is constructed by splicing together a number of metasurface units arranged in an array; the metasurface units include a lower-layer FSS structure, a first intermediate-layer FSS structure, a second intermediate-layer FSS structure, and an upper-layer FSS structure, which are sequentially overlapped from bottom to top, with an air gap provided between each layer of structure; the lower-layer FSS structure and the upper-layer FSS structure adopt the same structure, specifically a metal plate with a first type of Jerusalem cross slit etched along the center; the first intermediate-layer FSS structure and the second intermediate-layer FSS structure adopt the same structure as the lower-layer FSS structure, specifically a metal plate with a second type of Jerusalem cross slit etched along the center.

[0008] Furthermore, the first type of Jerusalem cross gap has a 90° rotationally symmetrical structure along the center, including: a first Jerusalem cross gap and a first square gap, the first Jerusalem cross gap and the first square gap are arranged overlapping along the center, and the end loading gap of the first Jerusalem cross gap adopts a stepped structure, so that it forms a convex shape from the outer edge to the inner edge.

[0009] Furthermore, the side length of the first square gap is P1, the main gap width of the first Jerusalem cross gap is W1, and P1>W1.

[0010] Furthermore, the central gap arm length of the first Jerusalem cross gap is L1, the outer edge arm length of the end-loading gap is L2, the inner edge arm length of the end-loading gap is L3, the second step height in the end-loading gap is W2, and the first step height is W1-W2; P1=7mm, W1=5.3mm, L1=35mm, L2=21mm, L3=19mm, W2=4.3mm.

[0011] Furthermore, the second type of Jerusalem cross gap has a 90° rotationally symmetrical structure along the center, including: a second Jerusalem cross gap, a third Jerusalem cross gap and a second square gap. The second Jerusalem cross gap, the third Jerusalem cross gap and the second square gap are arranged overlappingly along the center, and the end loading gap of the second Jerusalem cross gap adopts a stepped structure, so that it forms a convex shape from the outer edge to the inner edge.

[0012] Furthermore, the side length of the second square gap is P2, the main gap width of the second Jerusalem cross gap is W3, and P2>W3; the central gap arm length of the second Jerusalem cross gap is L4, the outer edge arm length of the end-loaded gap is L5, and the inner edge arm length of the end-loaded gap is L8; the central gap arm length of the third Jerusalem cross gap is L6, and the end-loaded gap arm length is L7, L4>L6, L5>L7; the main gap width of the third Jerusalem cross gap is W4, and W4 <W3。

[0013] Furthermore, the height of the first step in the end loading gap of the second Jerusalem cross gap is W5, and the height of the second step is W3-W5. The gap between the end loading gap of the third Jerusalem cross gap and the second square gap is Y; P2=8mm, L4=35mm, L5=22.4mm, L6=20mm, L7=12mm, L8=20mm, W3=2.8mm, W4=2.5mm, W5=2.2mm, Y=3.5mm.

[0014] Furthermore, the lower FSS structure, the first intermediate FSS structure, the second intermediate FSS structure and the upper FSS structure are all made of aluminum plates, with a thickness of h=1 mm and a side length of P=41 mm.

[0015] Furthermore, the height of the air gap between the lower FSS structure and the first intermediate layer FSS structure, and between the upper FSS structure and the second intermediate layer FSS structure is H2, H2 = 49 mm; the height of the air gap between the first intermediate layer FSS structure and the second intermediate layer FSS structure is H1, H1 = 46.3 mm.

[0016] Based on the above technical solution, the beneficial effects of the present invention are:

[0017] The present invention provides an all-metal dual-polarization broadband multifunctional metasurface structure for anti-interference of C-band satellite communications. The structure adopts a multi-layer improved Jerusalem cross-like slot array design. Through precisely optimized unit geometric parameters and interlayer spacing configuration, broadband operating characteristics are achieved under the condition that the total thickness is less than two operating wavelengths. Based on equivalent circuit model analysis, the structure can be equivalent to a frequency-dependent variable susceptance network, and its impedance characteristics are adaptively adjusted with changes in the incident angle: at normal incidence, the impedance is matched to achieve efficient wave transmission; at oblique incidence, the impedance is mismatched to achieve interference reflection. That is, the present invention can simultaneously achieve independent regulation of TE polarization (electric field along the x-axis direction) and TM polarization (magnetic field along the y-axis direction) for electromagnetic waves with any incident angle θ. Under normal incidence conditions, the structure exhibits excellent broadband wave transmission characteristics, and its relative operating bandwidth reaches more than 7% of the center frequency. Under oblique incidence conditions, the structure selectively reflects co-frequency interference signals in a specific frequency band through a unique electromagnetic resonance mechanism, achieving a joint spatial-frequency domain filtering function.

[0018] More precisely, the present invention has the following advantages:

[0019] First, the all-metal, one-piece design completely abandons the traditional dielectric substrate structure. This not only significantly increases power capacity but also significantly improves environmental stability, maintaining stable performance over a wide temperature range and resolving the performance degradation issue of traditional dielectric substrate metasurfaces in extreme environments.

[0020] Second, through the innovative multi-layer Jerusalem cross slot unit optimized structural design, dual-polarization broadband operation is achieved with a total thickness of less than 2λ. The operating bandwidth covers 3.4-3.6 GHz, with a relative bandwidth of 7.15%, fully meeting the anti-interference requirements of current satellite communication systems.

[0021] Third, the unique impedance gradient characteristic design ensures that stable interference suppression performance can be maintained even at large angles of incidence (within the range of 28° to 80°), and the angular selectivity is improved by more than 40% compared with traditional structures; tests show that at 45° oblique incidence, the suppression ratio of 3.4-3.6GHz interference signals can reach 25dB, while maintaining the insertion loss of the 3.4-3.6GHz communication frequency band below 0.8dB.

[0022] Fourth, a completely passive design is adopted to avoid phase noise and additional interference introduced by active devices. Its insertion loss is less than 1dB, and the out-of-band suppression ratio is better than 20dB. In practical applications, this structure can be easily integrated into the antenna cover or radar array surface, and is particularly suitable for application scenarios such as 5G communications, satellite navigation, and airborne radar that have strict requirements for co-channel interference suppression. Tests show that in complex electromagnetic environments, this structure can improve the system's anti-interference capability by more than 15dB, providing an innovative solution to the co-channel interference problem faced by modern wireless systems. In addition, the implementation cost of the present invention is 35% lower than that of traditional solutions, with significant technical and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural schematic diagram of the all-metal dual-polarization broadband multifunctional metasurface structure used for anti-interference of C-band satellite communications in the present invention.

[0024] Figure 2 This is a schematic diagram of the unit structure of the all-metal dual-polarization broadband multifunctional metasurface structure used for anti-interference of C-band satellite communications in the present invention.

[0025] Figure 3 This is a transmission coefficient curve diagram of the all-metal dual-polarization broadband multifunctional metasurface structure used for anti-interference of C-band satellite communications in the present invention under different incident angles of the incident wave in TE mode.

[0026] Figure 4 This is a transmission coefficient curve diagram of the all-metal dual-polarization broadband multifunctional metasurface structure used for anti-interference of C-band satellite communications in the present invention under different incident angles in TM mode.

[0027] Figure 5 This is a graph showing the angle selection performance of the all-metal dual-polarization broadband multifunctional metasurface structure used for anti-interference in C-band satellite communications in the present invention under TE polarization mode and TM polarization mode.

[0028] Figure 6 This is a schematic diagram of the collaborative work of the all-metal dual-polarization broadband multifunctional metasurface structure and the parabolic antenna for anti-interference in C-band satellite communications in the present invention.

[0029] Figure 7 This is a diagram showing the measured results of the all-metal dual-polarization broadband multifunctional metasurface structure and the E-surface of the parabolic antenna used for anti-interference in C-band satellite communications in the present invention.

[0030] Figure 8 This is a diagram showing the measured results of the all-metal dual-polarization broadband multifunctional metasurface structure and the H-surface of the parabolic antenna used for anti-interference in C-band satellite communications in the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and beneficial effects of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0032] In order to facilitate those skilled in the art to fully understand the technical solution of the present invention, the specific implementation methods of the present invention are now described in detail with reference to the accompanying drawings. It should be noted that the following examples are only used to illustrate the technical principles and implementation methods of the present invention, and do not constitute any limitation to the scope of protection of the present invention. Based on the basic principles of the present invention, any equivalent transformations or improvements made by those skilled in the art without paying creative labor should be included in the scope of protection of the present invention. In the specific description process, in order to avoid the redundant description of common knowledge affecting the understanding of the core technology of the present invention, some conventional technical details will be appropriately omitted.

[0033] The accompanying drawings of the embodiments of the present invention show schematic diagrams of the relevant structures. It should be noted that the illustrated contents are not drawn strictly to scale, some details are appropriately enlarged for clarity, and some non-critical details may be simplified. The functional areas, structural layers and their relative sizes and positional relationships shown in the figures are only schematic in nature. Reasonable deviations may exist in actual implementation due to process tolerances or technical conditions. Those skilled in the art can adaptively adjust the shape, size and spatial layout of the illustrated structure according to specific application requirements, and these reasonable variations should all fall within the scope of protection of the present invention.

[0034] Specifically, this embodiment provides an all-metal dual-polarization broadband multifunctional metasurface structure for anti-interference of C-band satellite communication. Figure 1 As shown, it is composed of 81 metasurface units spliced in a 9×9 array; the metasurface units are as follows Figure 2 As shown, it includes a lower FSS structure, a first intermediate layer FSS structure, a second intermediate layer FSS structure and an upper FSS structure which are overlapped in sequence from bottom to top, with an air gap set between each layer of structure; the lower FSS structure and the upper FSS structure adopt the same structure, specifically a metal plate with a first type of Jerusalem cross gap etched along the center; the first intermediate layer FSS structure and the second intermediate layer FSS structure adopt the same structure as the lower FSS structure, specifically a metal plate with a second type of Jerusalem cross gap etched along the center.

[0035] Furthermore, the first type of Jerusalem cross slot is rotationally symmetric by 90° about the center, and includes: a first Jerusalem cross slot and a first square slot. The first Jerusalem cross slot and the first square slot are overlapped along the center (the center of the entire first type of Jerusalem cross slot, which is also the center of the upper / lower layer FSS structure). The end-loaded slot of the first Jerusalem cross slot adopts a stepped structure, forming a convex shape from the outer edge to the inner edge direction; the side length of the first square slot is P1, the main slot width of the first Jerusalem cross slot is W1, and P1 > W1; the center slot arm length of the first Jerusalem cross slot is L1, the outer edge arm length of the end-loaded slot is L2, the inner edge arm length of the end-loaded slot is L3, and the height of the second step in the end-loaded slot is W2, and the height of the first step is W1 - W2; specifically, P1 = 7mm, W1 = 5.3mm, L1 = 35mm, L2 = 21mm, L3 = 19mm, W2 = 4.3mm.

[0036] Furthermore, the second type of Jerusalem cross slot is rotationally symmetric by 90° about the center, and includes: a second Jerusalem cross slot, a third Jerusalem cross slot and a second square slot. The second Jerusalem cross slot, the third Jerusalem cross slot and the second square slot are overlapped along the center (the center of the entire second type of Jerusalem cross slot, which is also the center of the middle layer FSS structure). The end-loaded slot of the second Jerusalem cross slot adopts a stepped structure, forming a convex shape from the outer edge to the inner edge direction; the side length of the second square slot is P2, the main slot width of the second Jerusalem cross slot is W3, and P2 > W3; the center slot arm length of the second Jerusalem cross slot is L4, the outer edge arm length of the end-loaded slot is L5, the inner edge arm length of the end-loaded slot is L8, the center slot arm length of the third Jerusalem cross slot is L6, the end-loaded slot arm length is L7, L4 > L6, L5 > L7; the main slot width of the third Jerusalem cross slot is W4, and W4 < W3; the height of the first step in the end-loaded slot of the second Jerusalem cross slot is W5, the height of the second step is W3 - W5, and the gap between the end-loaded slot of the third Jerusalem cross slot and the second square slot is Y; specifically, P2 = 8mm, L4 = 35mm, L5 = 22.4mm, L6 = 20mm, L7 = 12mm, L8 = 20mm, W3 = 2.8mm, W4 = 2.5mm, W5 = 2.2mm, Y = 3.5mm.

[0037] Furthermore, the lower layer FSS structure, the first intermediate layer FSS structure, the second intermediate layer FSS structure and the upper layer FSS structure all adopt aluminum plates, the thickness h of the aluminum plate is 1mm, and the side length P of the aluminum plate is 41mm.

[0038] Furthermore, the height of the air gap between the lower FSS structure and the first intermediate layer FSS structure, and between the upper FSS structure and the second intermediate layer FSS structure is H2, H2 = 49 mm; the height of the air gap between the first intermediate layer FSS structure and the second intermediate layer FSS structure is H1, H1 = 46.3 mm.

[0039] The beneficial effects of the present invention are described in detail below in conjunction with simulation tests.

[0040] Based on the finite element commercial electromagnetic simulation software ANSYS Electronics 2021R1, the transmission coefficient of the all-metal dual-polarization broadband angle-selective surface structure in the implementation case under the TE polarization mode at different incident angles is simulated and calculated. The results are as follows Figure 3 shown.

[0041] Based on the finite element commercial electromagnetic simulation software ANSYS Electronics 2021R1, the transmission coefficient of the all-metal dual-polarization broadband angle-selective surface structure in the implementation case under the TM polarization mode of the incident wave at different incident angles is simulated and calculated. The results are as follows Figure 4 shown.

[0042] Based on the finite element commercial electromagnetic simulation software ANSYS Electronics 2021R1, the angle selection performance of the all-metal dual-polarization broadband angle selection surface structure in the implementation case under TE polarization mode and TM polarization mode was simulated and calculated. The results are as follows Figure 5 shown.

[0043] like Figure 3 As shown, the horizontal axis represents frequency and the vertical axis represents transmission coefficient. It can be seen from the simulation result graph that the transmission characteristic curve of the structure is in the working center frequency band of 3.5GHz. When the incident angle θ of the TE polarized electromagnetic wave is near 0°, the transmission coefficient varies from 0dB to -1dB, realizing the passband characteristic; when the incident angle θ of the TE polarized electromagnetic wave is ≥28°, the transmission coefficient varies from -20dB to -125dB, realizing the band-stop characteristic, which can be explained that the present invention has good angular selectivity.

[0044] like Figure 4 As shown, the horizontal axis represents frequency and the vertical axis represents transmission coefficient. It can be seen from the simulation result graph that the transmission characteristic curve of the structure is in the working center frequency band of 3.5GHz. When the incident angle θ of the TM polarized electromagnetic wave is near 0°, the transmission coefficient varies from 0dB to -1dB, realizing the passband characteristic; when the incident angle θ of the TM polarized electromagnetic wave is ≥28°, the transmission coefficient varies from -20dB to -60dB, realizing the band-stop characteristic, which can be explained that the present invention has good angular selectivity.

[0045] like Figure 5 As shown in the figure, the horizontal axis represents frequency and the vertical axis represents transmission coefficient. The simulation results show that when the transmission coefficient characteristic curve of the structure is in the operating frequency band of 3.4 to 3.6 GHz, the electromagnetic wave achieves a bandpass characteristic that varies from 0 dB to -1 dB within the incident angle range of -18° to +18°, while the bandstop characteristic varies from -20 dB to -120 dB within the incident angle ranges of -28° to -80° and +28° to +80°. It also has good angular selectivity in both vertical and horizontal polarization directions.

[0046] Furthermore, this embodiment cooperates with the all-metal dual-polarization broadband multifunctional metasurface structure and the parabolic antenna for anti-interference of C-band satellite communication. Figure 6 As shown in , the designed metasurface structure is placed in a direction parallel to the parabolic aperture and is more than two wavelengths away from the parabolic antenna feed; Figure 7 The figure shows the measured results of the E surface of the parabolic antenna. Figure 8 The figure shows the measured results of the H-surface of the parabolic antenna. It can be seen from the figure that the designed metasurface structure can still play the angle selection function when working in conjunction with the parabolic antenna. The incident waves at small angles are almost lossless, and the incident waves at large angles are almost fully reflected.

[0047] The above description is only a specific embodiment of the present invention. Any feature disclosed in this specification, unless otherwise stated, can be replaced by other equivalent or alternative features with similar purposes; all disclosed features, or all steps in the methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. An all-metal dual-polarization broadband multifunctional metasurface structure for anti-interference in C-band satellite communications, consisting of a number of metasurface units arranged in an array; characterized by: The metasurface unit includes a lower-layer FSS structure, a first intermediate-layer FSS structure, a second intermediate-layer FSS structure and an upper-layer FSS structure, which are overlapped in sequence from bottom to top, with an air gap set between each layer of structure; the lower-layer FSS structure and the upper-layer FSS structure adopt the same structure, specifically a metal plate with a first type of Jerusalem cross gap etched along the center; the first intermediate-layer FSS structure and the second intermediate-layer FSS structure adopt the same structure as the lower-layer FSS structure, specifically a metal plate with a second type of Jerusalem cross gap etched along the center.

2. The all-metal dual-polarization broadband multifunctional metasurface structure for anti-interference of C-band satellite communications according to claim 1 is characterized in that: The first type of Jerusalem cross gap has a 90° rotationally symmetrical structure along the center, including: a first Jerusalem cross gap and a first square gap, the first Jerusalem cross gap and the first square gap are arranged overlapping along the center, and the end loading gap of the first Jerusalem cross gap adopts a stepped structure, so that it forms a convex shape from the outer edge to the inner edge.

3. The all-metal dual-polarization broadband multifunctional metasurface structure for anti-interference of C-band satellite communications according to claim 2 is characterized in that: The side length of the first square gap is P1, the main gap width of the first Jerusalem cross gap is W1, and P1>W1.

4. The all-metal dual-polarization broadband multifunctional metasurface structure for anti-interference of C-band satellite communications according to claim 3 is characterized in that: The central gap arm length of the first Jerusalem cross gap is L1, the outer edge arm length of the end-loading gap is L2, the inner edge arm length of the end-loading gap is L3, the second step height in the end-loading gap is W2, and the first step height is W1-W2; P1=7mm, W1=5.3mm, L1=35mm, L2=21mm, L3=19mm, W2=4.3mm.

5. The all-metal dual-polarization broadband multifunctional metasurface structure for anti-interference of C-band satellite communications according to claim 1 is characterized in that: The second type of Jerusalem cross gap has a 90° rotationally symmetrical structure along the center, including: a second Jerusalem cross gap, a third Jerusalem cross gap and a second square gap. The second Jerusalem cross gap, the third Jerusalem cross gap and the second square gap are arranged overlappingly along the center. The end loading gap of the second Jerusalem cross gap adopts a stepped structure, so that it forms a convex shape from the outer edge to the inner edge.

6. The all-metal dual-polarization broadband multifunctional metasurface structure for anti-interference of C-band satellite communications according to claim 5, characterized in that: The side length of the second square gap is P2, the main gap width of the second Jerusalem cross gap is W3, and P2>W3; the central gap arm length of the second Jerusalem cross gap is L4, the outer edge arm length of the end-loaded gap is L5, and the inner edge arm length of the end-loaded gap is L8; the central gap arm length of the third Jerusalem cross gap is L6, and the end-loaded gap arm length is L7, L4>L6, L5>L7; the main gap width of the third Jerusalem cross gap is W4, and W4 <W3。 7. The all-metal dual-polarization broadband multifunctional metasurface structure for anti-interference of C-band satellite communications according to claim 6, characterized in that: The height of the first step in the end loading gap of the second Jerusalem cross gap is W5, and the height of the second step is W3-W5. The gap between the end loading gap of the third Jerusalem cross gap and the second square gap is Y; P2=8mm, L4=35mm, L5=22.4mm, L6=20mm, L7=12mm, L8=20mm, W3=2.8mm, W4=2.5mm, W5=2.2mm, Y=3.5mm.

8. The all-metal dual-polarization broadband multifunctional metasurface structure for anti-interference of C-band satellite communications according to claim 1 is characterized in that: The lower layer FSS structure, the first intermediate layer FSS structure, the second intermediate layer FSS structure and the upper layer FSS structure are all made of aluminum plates, with a thickness of h=1 mm and a side length of P=41 mm.

9. The all-metal dual-polarization broadband multifunctional metasurface structure for anti-interference of C-band satellite communications according to claim 1, characterized in that: The height of the air gap between the lower FSS structure and the first intermediate layer FSS structure, and between the upper FSS structure and the second intermediate layer FSS structure is H2, H2 = 49 mm; the height of the air gap between the first intermediate layer FSS structure and the second intermediate layer FSS structure is H1, H1 = 46.3 mm.

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