Low-scattering large-angle wave-transparent electromagnetic metasurface based on angle multiplexing

Abstract

The application discloses a low-scattering large-angle wave-transparent electromagnetic metasurface based on angle multiplexing, which comprises an angle selection layer and a phase control layer; the phase control layer is used for controlling the reflection phase of an angle incident electromagnetic wave in a first range; the angle selection layer is used for selectively transmitting an angle incident electromagnetic wave in a second range and selectively reflecting an angle incident electromagnetic wave in the first range, and comprises a second dielectric substrate and metal grounds on the upper and lower surfaces of the second dielectric substrate, the upper metal ground is etched with first and second slot structures, and the lower metal ground is etched with third and fourth slot structures; the two layers of slot structures are arranged in a staggered mode in a unit arrangement direction of a plane, the first, second, third and fourth slot structures extend to the edges of the unit structures along another unit arrangement direction of the plane, and are in communication with the slot structures of adjacent units. The application realizes the integration of scattering suppression and large-angle wave-transparent functions, and effectively improves the function multiplexing capability and system integration degree of the electromagnetic metasurface device.

Description

Technical Field

[0001] This invention relates to a low-scattering, large-angle transparent electromagnetic metasurface based on angle reuse, belonging to the field of novel artificial electromagnetic devices. Background Technology

[0002] Electromagnetic metasurfaces are two-dimensional electromagnetic structures formed by the periodic arrangement of subwavelength-scale artificial units. By designing the geometry, dimensional parameters, and arrangement of these units, flexible control over the amplitude, phase, polarization, and propagation direction of electromagnetic waves can be achieved at the interface. Compared to traditional three-dimensional artificial electromagnetic materials, electromagnetic metasurfaces offer advantages such as thinness, high design freedom, and ease of integration, leading to widespread attention and application in electromagnetic wave manipulation, electromagnetic compatibility, and novel antenna systems. Through rational structural design, electromagnetic metasurfaces can achieve differentiated responses to electromagnetic waves under different incident conditions, such as control over reflection, transmission, or scattering, thus providing a new technical approach for the integrated design of multifunctional electromagnetic devices. Particularly in complex electromagnetic environments, achieving scattering suppression while ensuring electromagnetic wave transmission performance has become an important research direction in the design of radar radomes, aircraft structures, and electromagnetic functional structures.

[0003] In existing technologies, the design of transmissive metasurfaces mostly revolves around a single electromagnetic response function under specific incident conditions, such as achieving transmission enhancement or reflection control within a certain angle range. However, differentiated multiplexing designs for electromagnetic wave responses under different incident angles are still lacking. Especially in large-angle transmission scenarios, existing structures often only focus on the anti-reflection effect at the target angle, making it difficult to effectively control the scattering characteristics under normal incidence or other small-angle incidence. This is because large-angle transmission usually requires the structure to have low reflection and high transmission under the target incident conditions, while low-scattering design usually requires further control of the amplitude and phase of the reflected wave to reduce backscattering. The corresponding electromagnetic response targets are different. Due to the limited degree of freedom of traditional structures in the angular dimension, it is difficult to achieve independent design and collaborative optimization for different incident angles, making it difficult for devices to simultaneously meet the requirements of transmission performance at the operating angle and low scattering at the non-operating angle. Therefore, there is an urgent need to propose a design method that can achieve differentiated electromagnetic control for different incident angles to meet the needs of composite applications that require both transmission and low scattering. Summary of the Invention

[0004] Purpose of the invention: To address the shortcomings of existing technologies, the present invention aims to provide a low-scattering, large-angle transparent electromagnetic metasurface based on angle reuse, which enables differentiated electromagnetic response control for electromagnetic waves with different incident angles. It can achieve low-scattering characteristics while ensuring large-angle wave transmission performance, thus meeting the needs of composite applications that require both wave transmission and low scattering.

[0005] Technical Solution: To achieve the above-mentioned objectives, the present invention provides a low-scattering, large-angle transparent electromagnetic metasurface based on angle multiplexing, comprising a phase modulation layer and an angle selection layer; the phase modulation layer comprises a first dielectric substrate and a metal layer disposed on the surface of the first dielectric substrate, used to modulate the reflection phase of incident electromagnetic waves within a first range; the angle selection layer comprises a second dielectric substrate and an upper metal ground and a lower metal ground respectively disposed on the upper and lower surfaces of the second dielectric substrate, the upper metal ground being etched with a first slot structure and a second slot structure, and the lower metal ground being etched with a third slot structure and... The fourth slotted structure; wherein the slotted structures of the upper metal ground and the lower metal ground are staggered in one unit arrangement direction of the plane, and the first slotted structure, the second slotted structure, the third slotted structure and the fourth slotted structure extend to the edge of the unit structure along another unit arrangement direction of the plane and are connected to the slotted structure of the adjacent unit; by setting the geometric dimensions and relative positional relationship of the slotted structures, selective transmission of angle-incident electromagnetic waves in the second range and selective reflection of angle-incident electromagnetic waves in the first range are achieved; the first range and the second range do not overlap and the second range is larger than the first range.

[0006] Preferably, by adjusting the height of the spacer between the phase control layer and the angle selection layer, the electromagnetic coupling between the two layers is reduced, and the phase control layer's ability to control the reflected phase of electromagnetic waves within the first range is ensured.

[0007] Preferably, the spacer layer is an air spacer layer.

[0008] Preferably, the metal layer on the surface of the first dielectric substrate is composed of a first polarization phase-controlled microstrip line and a second polarization phase-controlled microstrip line arranged orthogonally to each other; the first polarization phase-controlled microstrip line is used to respond to electromagnetic waves incident in the first polarization direction; the second polarization phase-controlled microstrip line is used to respond to electromagnetic waves incident in the second polarization direction; the first polarization direction and the second polarization direction are orthogonal.

[0009] Preferably, the arm lengths of the first polarization phase-controlled microstrip line and the second polarization phase-controlled microstrip line are adjustable parameters, used to adjust the reflection phases of electromagnetic waves incident in the first polarization direction and the second polarization direction, respectively.

[0010] Preferably, the first and second slotted structures located on the upper metal ground and the third and fourth slotted structures located on the lower metal ground are staggered in a unit arrangement direction on the plane to achieve angle-selective transmission of obliquely incident electromagnetic waves within the second range.

[0011] Preferably, a first metal connecting line is retained between the first slotted structure and the second slotted structure for connecting adjacent units; a second metal connecting line is retained between the third slotted structure and the fourth slotted structure for connecting adjacent units; the first slotted structure, the second slotted structure, the third slotted structure and the fourth slotted structure have the same geometric dimensions.

[0012] Preferably, the first, second, third, and fourth slotted structures are all arranged along the edge of the unit, and the slot width does not exceed half of the unit period size. By adjusting the slot width, the unit period size, and the dielectric thickness of the second dielectric substrate, the equivalent impedance matching state under different incident angles can be adjusted to achieve selective transmission of electromagnetic waves incident at angles within the second range and selective reflection of electromagnetic waves incident at angles within the first range.

[0013] Preferably, the first range is 0°~30° and the second range is 85°±2°.

[0014] Preferably, the phase modulation layer achieves scattering suppression through phase coding arrangement.

[0015] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0016] 1. In the electromagnetic metasurface provided by this invention, the angle selection layer, by introducing staggered and interconnected slotted structures on the upper and lower metal ground layers disposed on the upper and lower surfaces of the second dielectric substrate, and combining the geometric dimensions, relative positional relationships, periodic dimensions, and dielectric thickness design of the slotted structures, can achieve selective electromagnetic response to electromagnetic waves with different incident angles. This allows the structure to selectively transmit under large-angle incident conditions in the second range, while maintaining selective reflection under small-angle incident conditions in the first range. Furthermore, the phase modulation layer, through mutually orthogonal first and second polarization phase modulation microstrip lines disposed on the surface of the first dielectric substrate, modulates the reflection phase of electromagnetic waves incident at small angles in the first range, and can achieve scattering suppression by combining phase coding arrangement. Through the division of labor and synergy of the above two layers, this invention can achieve differentiated electromagnetic responses for electromagnetic waves with different incident angles, realize functional separation and reuse within the angular domain dimension, expand the functional design dimensions of traditional electromagnetic metasurfaces, and improve the electromagnetic function integration capability.

[0017] 2. In the electromagnetic metasurface provided by the present invention, through the structural design of the angle-selective layer and the optimization of the slot structure parameters, it is possible to achieve input impedance adjustment and angle-selective anti-reflection for electromagnetic waves incident at large angles within the second range. Compared with traditional pure dielectric substrates of the same thickness, it can effectively reduce transmission insertion loss and improve electromagnetic wave transmission efficiency under large-angle oblique incidence conditions, thereby significantly improving large-angle wave transmission performance.

[0018] 3. In the electromagnetic metasurface provided by this invention, the synergistic design of the angle selection layer and the phase control layer ensures the large-angle wave transmission performance while achieving phase control of the reflection of dual-polarized electromagnetic waves at small angles, especially under normal incidence conditions. Furthermore, the phase coding arrangement achieves scattering suppression, thereby overcoming the design limitation of traditional structures where it is difficult to balance wave transmission performance and low scattering performance.

[0019] 4. The electromagnetic metasurface provided by this invention adopts a layered electromagnetic metasurface structure. Through parametric design, multiple electromagnetic functions such as angle selection, phase modulation and scattering suppression can be integrated. The structure is simple, has a high degree of design freedom, and is easy to implement in engineering and system integration. It has good application prospects in radar radome, aircraft structure and electromagnetic functional structure design. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the low-scattering, large-angle transparent electromagnetic metasurface provided in an embodiment of the present invention (the phase modulation layer is partially missing in the figure to show the angle selection layer below).

[0021] Figure 2 The following is a basic unit structure design diagram of the low-scattering, large-angle transparent electromagnetic metasurface provided in the embodiment of the present invention, wherein (a) is a three-dimensional view of the unit structure, (b) is a planar structural schematic diagram of the phase modulation layer structure, (c) is a planar structural schematic diagram of the upper surface of the angle selection layer, and (d) is a planar structural schematic diagram of the lower surface of the angle selection layer.

[0022] Figure 3 The low-scattering, large-angle transparent electromagnetic metasurface provided in this embodiment of the invention exhibits a reflection coefficient S of electromagnetic waves incident from 0° to 30° under TE (Transverse Electric) and TM (Transverse Magnetic) polarization conditions. 11 and transmission coefficient S 21 The simulation results are shown in the figure, where (a) is the simulation result of TE polarization and (b) is the simulation result of TM polarization.

[0023] Figure 4 The low-scattering, large-angle transparent electromagnetic metasurface provided in this embodiment of the invention exhibits a reflection coefficient S of electromagnetic waves incident at 85° ± 2° under TM polarization conditions. 11 and transmission coefficient S 21 The simulation results are shown in the figure.

[0024] Figure 5The low-scattering, large-angle transparent electromagnetic metasurface provided in this embodiment of the invention is shown in the figure. When the phase control layer structure parameters of TE polarized wave and TM polarized wave are adjusted, the reflection coefficient amplitude and reflection phase change results of different unit structures are shown. Among them, (a) is the simulation result of TE polarization and (b) is the simulation result of TM polarization.

[0025] Figure 6 The simulation results of the transmission far-field distribution of an 85° incident TM-polarized wave at different frequencies are shown in the figure, after the low-scattering, large-angle transparent electromagnetic metasurface provided in the embodiments of the present invention is randomly encoded and arranged. (a) represents 8 GHz, (b) represents 10 GHz, and (c) represents 12 GHz. In the figure, k represents the incident direction of the electromagnetic wave, E represents the direction of the electric field, and θ... i This indicates the angle between the incident direction and the normal direction.

[0026] Figure 7 The simulation results of the far-field distribution of scattering suppression for TE-polarized waves incident at 0° at different frequencies are shown in the figures below. The results are obtained by randomly coded arrangement of the low-scattering, large-angle transparent electromagnetic metasurface provided in this embodiment of the invention. In the figures, (a) represents 8 GHz, (b) represents 10 GHz, and (c) represents 12 GHz. In the figures, k represents the incident direction of the electromagnetic wave, E represents the direction of the electric field, and θ... i This indicates the angle between the incident direction and the normal direction.

[0027] Figure 8 The simulation results of the far-field distribution of scattering suppression for 0° incident TM polarized waves at different frequencies are shown in the figures below. The results are obtained by randomly coded arrangement of the low-scattering, large-angle transparent electromagnetic metasurface provided in this embodiment of the invention. In the figures, (a) represents 8 GHz, (b) represents 10 GHz, and (c) represents 12 GHz. In the figures, k represents the incident direction of the electromagnetic wave, H represents the direction of the magnetic field, and θ... i This indicates the angle between the incident direction and the normal direction.

[0028] Figure 9 The diagram shows the results of the radar scattering reduction (RCSR) value as a function of frequency under TE and TM polarized electromagnetic wave conditions at 0° ~ 30° after random coding arrangement of the low scattering large-angle transparent electromagnetic metasurface provided in the embodiments of the present invention. Among them, (a) is the simulation result of TE polarization and (b) is the simulation result of TM polarization.

[0029] Figure label: Figure 2 In the diagram, 1-y-polarization phase-controlled microstrip line; 2-x-polarization phase-controlled microstrip line; 3-upper metal ground; 4-first slotted structure; 5-second slotted structure; 6-third slotted structure; 7-fourth slotted structure; 8-lower metal ground. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0031] like Figure 1 As shown in the figure, an embodiment of the present invention discloses a low-scattering, large-angle transparent electromagnetic metasurface based on angle multiplexing, comprising a phase modulation layer and an angle selection layer; wherein, the phase modulation layer comprises a first dielectric substrate and a metal layer disposed on the surface of the first dielectric substrate, used to control the reflection phase of incident electromagnetic waves within a first range; the angle selection layer comprises a second dielectric substrate and an upper metal ground and a lower metal ground disposed on the upper and lower surfaces of the second dielectric substrate respectively, the upper metal ground being etched with a first slot structure and a second slot structure, and the lower metal ground being etched with a third slot structure and a fourth slot structure; wherein, the slot structures of the upper metal ground and the lower metal ground are staggered in one unit arrangement direction of the plane, and the first slot structure, the second slot structure, the third slot structure and the fourth slot structure extend to the edge of the unit structure along another unit arrangement direction of the plane and communicate with the slot structure of the adjacent unit; by setting the geometric dimensions and relative positional relationship of the slot structures, selective transmission of incident electromagnetic waves within a second range and selective reflection of incident electromagnetic waves within a first range are achieved; the first range and the second range do not overlap and the second range is larger than the first range.

[0032] In this embodiment, the first range is 0°~30°, and the second range is 85°±2°. The angles within the first range are called small angles, and the angles within the second range are called large angles.

[0033] In this embodiment, the xOz plane is taken as the incident plane. Under the condition of normal incident (incident angle of 0°), the incident electromagnetic wave can be defined as two polarization forms: x polarization and y polarization. Under the condition of oblique incident (incident angle of non-0°), according to the definition of electromagnetic wave polarization relative to the incident plane, the x-polarized wave in the xOz incident plane corresponds to the TM polarized wave, and the y-polarized wave perpendicular to the xOz incident plane corresponds to the TE polarized wave.

[0034] The low-scattering, large-angle transparent electromagnetic metasurface based on angle reuse provided in this embodiment achieves selective transmission of large-angle incident TM-polarized electromagnetic waves and selective reflection of small-angle incident dual-polarized electromagnetic waves through the structural design of the angle-selective layer.

[0035] In some alternative implementations, to achieve phase modulation of reflected electromagnetic waves incident at small angles with dual polarization, the phase modulation layer adopts a cross-shaped microstrip resonant structure. The metal layer on the surface of the first dielectric substrate is composed of a first polarization phase modulation microstrip line and a second polarization phase modulation microstrip line arranged orthogonally. The first polarization phase modulation microstrip line responds to electromagnetic waves incident in the first polarization direction; the second polarization phase modulation microstrip line responds to electromagnetic waves incident in the second polarization direction. The first and second polarization directions are orthogonal, and the arm lengths of the first and second polarization phase modulation microstrip lines are adjustable parameters used to adjust the reflection phases of electromagnetic waves incident in the first and second polarization directions, respectively, thereby providing a phase modulation basis for reducing the radar cross-section under small-angle incident conditions.

[0036] In some optional implementations, the first and second slotted structures located on the upper metal ground layer and the third and fourth slotted structures located on the lower metal ground layer are staggered in one unit arrangement direction on the plane to achieve angle-selective transmission of large-angle obliquely incident electromagnetic waves; a first metal connecting line is retained between the first and second slotted structures to connect adjacent units; a second metal connecting line is retained between the third and fourth slotted structures to connect adjacent units; the first, second, third, and fourth slotted structures have the same geometric dimensions; the first, second, third, and fourth slotted structures are all set along the edge of the unit, and the slot width does not exceed half of the unit period dimension, that is, the slotted structures in the upper and lower layers do not overlap; by adjusting the slot width, the unit period dimension, and the dielectric thickness of the second dielectric substrate, the equivalent impedance matching state under different incident angles is adjusted to achieve selective transmission of large-angle incident electromagnetic waves and selective reflection of small-angle incident electromagnetic waves.

[0037] In this embodiment, to reduce the electromagnetic coupling between the phase modulation layer and the angle selection layer while ensuring the phase modulation capability of small-angle reflected electromagnetic waves, a spacer layer of height h is provided between the angle selection layer and the phase modulation layer, preferably an air spacer layer, such as... Figure 2 As shown.

[0038] Figure 2Schematic diagrams of a preferred planar structure for the angle selection layer and phase modulation layer are provided. The provided low-scattering, large-angle transparent electromagnetic metasurface consists of an angle selection layer and a phase modulation layer. The phase modulation layer is composed of a y-polarized phase-modulated microstrip line 1 and an x-polarized phase-modulated microstrip line 2, which are orthogonally arranged along the y and x directions, respectively. Together, they form a cross-shaped resonant structure, and the arm length is an adjustable design parameter. By adjusting the arm length, independent modulation of the reflection phase of the two polarized electromagnetic waves can be achieved. The upper metal ground 3 of the angle selection layer is etched with a first slot structure 4 and a second slot structure 5. A metal line with a width of w1 is retained between the first slot structure 4 and the second slot structure 5 for connecting with adjacent units in the x direction. The lower metal ground 8 of the angle selection layer is etched with a third slot structure 6 and a fourth slot structure 7. A metal line with a width of w2 is retained between the third slot structure 6 and the fourth slot structure 7 for connecting with adjacent units in the x direction. The upper and lower slot structures are staggered in the x direction and have the same structural geometric parameters, and extend to the edge of the unit structure in the y direction to connect with the slot structure of the adjacent unit. The principle behind the function of the angle-selective layer is as follows: When electromagnetic waves are incident at small angles within the range of 0° to 30°, the excitation of the upper and lower slotted structures by the incident waves is weak, and the angle-selective layer as a whole still exhibits strong metallic reflection characteristics, thereby achieving selective reflection of electromagnetic waves incident at small angles. When TM-polarized electromagnetic waves are incident at large angles of 85°±2°, the tangential field component of the incident waves on the surface of the structure increases significantly, enhancing the excitation of the slotted structures. Stronger electromagnetic coupling is formed between the staggered slotted structures of the upper and lower layers, allowing the electromagnetic waves to propagate layer by layer through the slotted area. By further adjusting the geometric dimensions, staggered arrangement, periodic parameters, and dielectric layer thickness of the upper and lower slotted structures, the angle-selective layer can meet optimal equivalent transmission conditions within the target large angle range, thereby achieving selective transmission of TM-polarized electromagnetic waves at large angles of 85°±2°, while maintaining reflection characteristics in non-target angle ranges.

[0039] Based on the above unit design, this embodiment uses the commercial full-wave simulation software CST Microwave Studio (CST-MWS) to simulate the unit structure. Periodic boundary conditions are set around the perimeter of the unit structure in the simulation, while the longitudinal direction is set as an open boundary. In the far-field simulation, open boundary conditions are used around the perimeter and in the longitudinal direction. The dielectric substrate selected in this embodiment is F4BM, with a dielectric constant of 2.65 and a loss tangent of 0.001. Figure 2The basic parameters of the unit cell model shown are as follows: unit cell period p = 13 mm; air gap layer thickness h = 3 mm; dielectric substrate thickness ts1 = 0.5 mm, ts2 = 0.5 mm; upper metal ground plane width L1 = 10 mm; upper metal microstrip width w1 = 0.5 mm; lower metal ground plane width L2 = 10 mm; lower metal microstrip width w2 = 0.5 mm.

[0040] Figure 3 The reflection coefficient S of a low-scattering, large-angle transparent electromagnetic metasurface for incident electromagnetic waves in the range of 0° to 30° under TE and TM polarization conditions is given. 11 and transmission coefficient S 21 The simulation results show that the low-scattering, large-angle transparent electromagnetic metasurface described in this embodiment exhibits high reflection characteristics for TE-polarized waves incident at 0° to 30° within the 6 to 12 GHz frequency band, and high reflection characteristics for TM-polarized waves incident at 0° to 30° within the 8 to 11.5 GHz frequency band.

[0041] Figure 4 The reflection coefficient S of a low-scattering, large-angle transparent electromagnetic metasurface for electromagnetic waves incident at 85° ± 2° under TM polarization conditions is given. 11 and transmission coefficient S 21 Simulation results show that the low-scattering, large-angle transparent electromagnetic metasurface described in this embodiment exhibits high-efficiency transmission characteristics for TM polarized waves incident at 85° ± 2° within the 6 ~ 12 GHz frequency band, with a transmission coefficient S 21 The amplitude is higher than -2 dB.

[0042] Figure 5 This paper presents the results of the amplitude and phase change of the reflection coefficients of TE-polarized and TM-polarized waves under different unit structures when the phase control layer structural parameters are adjusted under the low-scattering, large-angle transparent electromagnetic metasurface described in this embodiment are adjusted for incident electromagnetic waves at 0° to 30°. To achieve scattering reduction of small-angle incident electromagnetic waves, this embodiment adopts a 1-bit reflection phase control method, defining two basic coding units "0" and "1", corresponding to reflection phase differences of 0° and 180°, respectively. According to the resonance characteristics of the cross-shaped resonant structure, when the arm lengths of the y-polarized phase control microstrip line 1 and the x-polarized phase control microstrip line 2 are 3 mm and 5 mm, respectively, coding unit "0" can be formed, while when the arm lengths are adjusted to 11 mm and 13 mm, respectively, coding unit "1" can be formed. Simulation results show that after adjusting the phase control microstrip line structure, both coding units can achieve efficient reflection of incident dual-polarized electromagnetic waves in the range of 0° to 30°, forming a reflection phase difference of approximately 180° ± 37°, satisfying the phase condition of scattering cancellation.

[0043] Based on this, the two basic coding units were randomly encoded and arranged, and far-field simulation analysis was performed on the array structure under 85° TM polarization incident, 0° TE polarization incident, and 0° TM polarization incident conditions. The results are as follows: Figure 6 , Figure 7 and Figure 8 As shown in the figure. Simulation results show that the metasurface array with random coding arrangement can maintain high transmission efficiency under 85° TM polarization incident conditions, while achieving uniform diffusion of scattered energy for 0° TE polarization and 0° TM polarization incident electromagnetic waves, thereby effectively reducing the radar cross section.

[0044] Figure 9 The results show that the radar cross section reduction (RCSR) of the electromagnetic metasurface described in this embodiment, after random coding and arrangement, varies with frequency under dual-polarized incident conditions. Simulation results show that, compared with a metal plate of the same size, this metasurface array achieves an RCS reduction of more than 10 dB for TE-polarized and TM-polarized waves in the 7.2 ~ 14.5 GHz and 8.1 ~ 13.5 GHz frequency bands, respectively, and remains relatively stable in the 0° ~ 30° incident range.

[0045] Relational terms such as “first” and “second” in this application are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0046] The above embodiments are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and equivalent substitutions without departing from the principles of the present invention. For example, migrating to other frequency bands in single-polarization or dual-polarization states to achieve angle multiplexing functions where large-angle transmission and small-angle scattering cancel each other out, or adjusting the phase coding precision and coding arrangement of the phase modulation layer to obtain different angle multiplexing electromagnetic function designs. All technical solutions that improve upon or make equivalent substitutions to the claims of the present invention fall within the protection scope of the present invention.

Claims

1. A low-scattering, large-angle transparent electromagnetic metasurface based on angle reuse, characterized in that, The system includes a phase modulation layer and an angle selection layer. The phase modulation layer comprises a first dielectric substrate and a metal layer disposed on the upper surface of the first dielectric substrate, used to modulate the reflected phase of an incident electromagnetic wave within a first range. The metal layer on the upper surface of the first dielectric substrate is composed of a first polarization phase modulation microstrip line and a second polarization phase modulation microstrip line arranged orthogonally to each other. The phase modulation layer achieves scattering suppression through phase coding arrangement. The angle selection layer comprises a second dielectric substrate and an upper metal ground and a lower metal ground respectively disposed on the upper and lower surfaces of the second dielectric substrate. The upper metal ground is etched with a first slot structure and a second slot structure, and the lower metal ground is etched with a third slot structure and a fourth slot structure. The slot structures of the upper and lower metal grounds are staggered in a unit arrangement direction in a plane, and the first, second, third, and fourth slot structures are... The structure extends along another unit arrangement direction in the plane to the edge of the unit structure and communicates with the slotted structure of the adjacent unit; the first slotted structure and the second slotted structure are arranged on the upper surface of the second dielectric substrate in one unit, along the right / left side of the unit, and the edges of the first slotted structure and the second slotted structure coincide with the right / left edge of the unit structure; the third slotted structure and the fourth slotted structure are arranged on the lower surface of the second dielectric substrate in the same unit, and along the opposite side of the right / left side of the unit, and the edges of the third slotted structure and the fourth slotted structure coincide with the opposite side edge; by setting the geometric dimensions and relative positional relationship of the slotted structures, selective transmission of angle-incident electromagnetic waves in the second range and selective reflection of angle-incident electromagnetic waves in the first range are achieved; the first range and the second range do not coincide, and the angle value corresponding to the second range is greater than the angle value corresponding to the first range.

2. The low-scattering, large-angle transparent electromagnetic metasurface based on angle reuse according to claim 1, characterized in that, By adjusting the height of the gap between the phase control layer and the angle selection layer, the electromagnetic coupling between the two layers is reduced, and the phase control layer's ability to control the reflected phase of incident electromagnetic waves within the first range is ensured.

3. The low-scattering, large-angle transparent electromagnetic metasurface based on angle reuse according to claim 2, characterized in that, The spacer layer is an air spacer layer.

4. The low-scattering, large-angle transparent electromagnetic metasurface based on angle reuse according to claim 1, characterized in that, The first polarization phase-controlled microstrip line is used to respond to electromagnetic waves incident in the first polarization direction; the second polarization phase-controlled microstrip line is used to respond to electromagnetic waves incident in the second polarization direction. The first polarization direction is orthogonal to the second polarization direction.

5. The low-scattering, large-angle transparent electromagnetic metasurface based on angle reuse according to claim 4, characterized in that, The arm lengths of the first and second polarization phase-controlled microstrip lines are adjustable parameters, used to adjust the reflection phases of electromagnetic waves incident in the first polarization direction and the second polarization direction, respectively.

6. The low-scattering, large-angle transparent electromagnetic metasurface based on angle reuse according to claim 1, characterized in that, The first and second slotted structures located on the upper metal ground and the third and fourth slotted structures located on the lower metal ground are staggered in a unit arrangement direction on the plane to achieve angular selective transmission of obliquely incident electromagnetic waves within the second range.

7. The low-scattering, large-angle transparent electromagnetic metasurface based on angle reuse according to claim 1, characterized in that, A first metal connecting line is retained between the first slotted structure and the second slotted structure for connecting adjacent units; A second metal connecting line is retained between the third slotted structure and the fourth slotted structure for connecting adjacent units; The first slotted structure, the second slotted structure, the third slotted structure, and the fourth slotted structure have the same geometric dimensions.

8. The low-scattering, large-angle transparent electromagnetic metasurface based on angle reuse according to claim 1, characterized in that, The first, second, third, and fourth slotted structures are all set along the edge of the unit, and the slot width does not exceed half of the unit period size. By adjusting the slot width, the unit period size, and the dielectric thickness of the second dielectric substrate, the equivalent impedance matching state under different incident angles is adjusted, thereby achieving selective transmission of electromagnetic waves incident at angles within the second range and selective reflection of electromagnetic waves incident at angles within the first range.

9. The low-scattering, large-angle transparent electromagnetic metasurface based on angle reuse according to claim 1, characterized in that, The first range is 0° to 30°, and the second range is 85° ± 2°.

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