Metasurface array antenna housing

Abstract

The metasurface array antenna housing comprises a plurality of array units of the same structure, each array unit sequentially comprises a first lightning protection layer from top to bottom, and each first lightning protection layer comprises four copper metal cylinders and a lightning protection top layer drainage metal patch; the second metasurface wave absorbing and transmitting layer comprises a first dielectric substrate, and four quasi-rectangular patches, four lumped resistors, four quasi-triangular patches and four quasi-square rings which are arranged on the upper surface of the first dielectric substrate; the third metasurface wave-transparent layer comprises a square metal patch, and a first circular ring and a second circular ring are etched on the square metal patch. Lightning is guided to the third metasurface wave-transparent layer through the first lightning protection layer, the lightning is conducted to other areas through the metal patch, damage of the lightning to the antenna housing is effectively avoided, and the antenna housing can directly replace a lightning protection strip for use; the structural size is greatly reduced, the angle stability is improved, and integration is facilitated; the copper-clad surface of the third metasurface wave-transparent layer can be used as a metal back plate of the second metasurface wave-absorbing layer, and structural multiplexing is achieved.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic wave modulation technology, and in particular to a metasurface array antenna radome. Background Technology

[0002] Metasurfaces, as subwavelength-thickness artificial microstructures, possess the ability to flexibly control electromagnetic wave reflection, transmission, and absorption characteristics. Traditional metasurface designs typically focus on a single electromagnetic function, but in complex applications such as radar stealth and communication compatibility, the system needs to possess both wave transmission and absorption capabilities. Currently, the mainstream approach to solving this problem is to use a modular structure, but this method has significant drawbacks. Due to the complex design involving multiple levels and materials, the resulting devices are not only bulky but also have thick profiles. Furthermore, the strong coupling effect between structural units leads to poor frequency selectivity in the modular structure, making it difficult to ensure performance stability while simultaneously achieving multiple electromagnetic parameters.

[0003] The invention patent application with application number 202511129023.7 discloses a dual-frequency selective surface radome. Although it achieves advantages such as dual-frequency dual-polarization, high frequency selectivity, and large-angle incident stability through a combination design of an improved square slot ring and an improved Jerusalem cross slot, it still has obvious limitations: its complex structure, which uses five layers of metal and four layers of dielectric material stacked alternately, requires strict alignment accuracy between layers, is difficult to process and assemble, and is costly. Furthermore, its overall thickness and weight are relatively large, hindering further miniaturization and integration. Simultaneously, the core metal layer is a slotted resonant structure without a continuous conductive path, lacking lightning discharge and surge protection capabilities. In outdoor applications, it is prone to dielectric breakdown and pattern burn-out due to lightning strikes, resulting in insufficient reliability and environmental adaptability. In addition, this structure only has frequency-selective wave transmission capabilities and lacks broadband wave absorption characteristics, failing to effectively suppress the radar cross section (RCS) of the antenna system. In stealth applications, it easily exposes targets and cannot meet the requirements for low detectability.

[0004] The metasurface array radome designed in the invention patent application with application number 202511062945.0, although achieving single-frequency wave transmission and dual-band wave absorption electromagnetic functions through a three-layer structure, has many shortcomings in practical applications: it only supports single-band wave transmission, which cannot meet the actual needs of current multi-frequency communication; the three-layer structure design is cumbersome, with low structural integration and functional reusability, and the array unit size of 20mm×20mm is relatively large, which is not conducive to the miniaturization and integration of equipment; the radome is not designed with any lightning protection structure, making it less suitable for airborne, outdoor and other scenarios prone to lightning strikes, and the device is easily damaged by lightning strikes during use; at the same time, its metal microstructure design is complex, containing many circular structures, which greatly increases the processing difficulty and is not conducive to industrial mass production.

[0005] Therefore, developing a new type of frequency selective surface radome with a more compact structure, simpler manufacturing process, and basic lightning protection capabilities is of great significance for promoting its engineering application in complex scenarios such as airborne and outdoor base stations. Summary of the Invention

[0006] To address the problems of existing radomes that are difficult to integrate lightning protection, wave absorption, and wave transmission functions, and that have large structural dimensions, poor integration, and inadequate lightning protection, the present invention aims to provide a metasurface array radome with excellent lightning protection, broadband wave absorption with low impact on wave transmission, excellent wave transmission performance, and strong structural adaptability.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a metasurface array radome, comprising multiple array elements with identical structures, the array elements being periodically arranged in a tightly fitted manner, with the edges of adjacent array elements seamlessly connected and sequentially connected along a predetermined direction; the array elements, from top to bottom, comprise a first lightning protection layer, a second metasurface absorbing and transmitting layer, and a third metasurface transmitting layer; the first lightning protection layer comprises four copper metal cylinders and a lightning protection top layer current-draining metal patch disposed on the top of the copper metal cylinders; the second metasurface absorbing and transmitting layer comprises a first dielectric substrate and four rectangular patches, four lumped resistors, four triangular patches, and four square rings disposed on the upper surface of the first dielectric substrate; the third metasurface transmitting layer comprises a second dielectric substrate and a square metal patch disposed on the upper surface of the second dielectric substrate, with a first ring and a second ring etched on the square metal patch; the second and third metasurface absorbing and transmitting layers are arranged parallel to each other, and the center lines of the second and third metasurface absorbing and transmitting layers are coaxial.

[0008] The four copper metal cylinders have the same structure, all being quarter-cylindrical structures, meaning the cross-section of the copper metal cylinder is a quarter-circle cross-section; the lightning protection top layer current-guiding metal patch is L-shaped; the four copper metal cylinders pass through the four corner notches of the second metasurface absorbing and transmitting layer and contact the upper surface of the third metasurface transmitting layer, guiding the received lightning current to the copper-clad surface of the third metasurface transmitting layer.

[0009] The rectangular patch is roughly rectangular in shape, with a triangular notch etched at the center of its bottom. A lumped resistor is connected to each of the two corners of its bottom. Four rectangular patches are arranged opposite each other and interconnected via lumped resistors to form a circle. A triangular patch is positioned above the rectangular patch, with the top of the triangular patch connecting downwards to the rectangular patch. Two circular holes are etched on the rectangular patch. A square ring is positioned at the bottom of the rectangular patch, with a first comb-shaped structure and a second comb-shaped structure forming inwards along the bottom edge of the square ring. The first comb-shaped structure includes a first rectangular strip and an inwardly opening first rectangular ring. The inner side of the ring has three sets of first symmetrical branches distributed at equal intervals, and the first rectangular strip extending into the first rectangular ring has three sets of first rectangular branches distributed at equal intervals. The three sets of first symmetrical branches and the three sets of first rectangular branches are arranged alternately. The second comb-shaped structure includes a second rectangular strip and an outwardly opening second rectangular ring. The inner side of the second rectangular ring has three sets of second symmetrical branches distributed at equal intervals, and the second rectangular strip extending into the second rectangular ring has two sets of second rectangular branches distributed at equal intervals. The three sets of second symmetrical branches and the two sets of second rectangular branches are arranged alternately. The four corners of the first dielectric substrate are provided with arc-shaped notches for four copper metal cylinders to pass through.

[0010] The first ring and the second ring are concentric circles. The outer diameter of the first ring is 7 mm and the inner diameter is 6.2 mm. The outer diameter of the second ring is 9.5 mm and the inner diameter is 8.7 mm.

[0011] The distance between the lower surface of the second metasurface absorbing and transmitting layer and the upper surface of the third metasurface transmitting layer is set to one-quarter of the wavelength of the center frequency of the absorption band, i.e., 5 mm.

[0012] Both the first and second dielectric substrates are made of Rogers RT or Duroid 5880 high-frequency microwave laminates with a relative permittivity of 2.2 and a dielectric loss tangent of 0.0009. The array unit has a size of 15.4mm × 15.4mm, and the thickness of both the first and second dielectric substrates is 1mm.

[0013] The lumped resistor has a resistance of 305Ω. The metal patches in the first lightning protection layer, the second metasurface absorbing and transmitting layer, and the third metasurface transmitting layer are all made of pure copper with a thickness of 0.035mm, and are fabricated on the surface of the first dielectric substrate or the second dielectric substrate by PCB photolithography etching process.

[0014] As can be seen from the above technical solution, the beneficial effects of the present invention are as follows: First, excellent lightning protection effect: The present invention guides lightning to the third metasurface wave-transparent layer through the first lightning protection layer. The lightning is conducted to other areas through the metal patch, effectively avoiding damage to the radome by lightning. It can be directly used as a lightning protection strip and has almost no impact on the performance of the radome itself. At the same time, the plate material can be flexibly replaced according to actual needs, with strong adaptability; Second, achieving broadband absorption and low-impact wave transmission: The second metasurface wave-absorbing layer can generate an absorption effect. Electromagnetic waves of different frequencies resonate in this layer and are absorbed. Some of the absorbed frequency band electromagnetic waves are absorbed between the first metasurface wave-transparent layer. After secondary reflection, it is completely absorbed; through the combination of multi-resonant structures, while achieving the wave absorption function, the interference to the wave transmission band is greatly reduced, achieving broadband wave absorption effect at low and medium frequencies; third, it has excellent wave transmission performance and strong structural adaptability: the second metasurface wave transmission layer can re-radiate electromagnetic waves in the communication band, allowing them to pass smoothly through the metasurface unit; combined with the frequency selective resonator and the wave transmission slotted metal, the structural size is greatly reduced, the angular stability is improved, and integration is convenient while ensuring wave transmission performance; at the same time, the copper-clad surface of the third metasurface wave transmission layer can be used as the metal backing plate of the second metasurface wave absorption layer, realizing structural reuse. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the first lightning protection layer in this invention;

[0016] Figure 2 This is a schematic diagram of the structure of the second metasurface absorbing and transmitting layer in this invention;

[0017] Figure 3 This is a schematic diagram of the structure of the third metasurface wave-transparent layer in this invention;

[0018] Figure 4 This is the S-parameter curve of the present invention. Detailed Implementation

[0019] A metasurface array radome includes multiple array elements with identical structures, arranged periodically in a tightly fitted manner, with the edges of adjacent array elements seamlessly connected and sequentially connected along a predetermined direction. From top to bottom, each array element comprises a first lightning protection layer, a second metasurface absorbing and transmitting layer, and a third metasurface transmitting layer. The first lightning protection layer includes four copper cylinders 2 and a lightning protection top-layer current-guiding metal patch 1 disposed on the top of the copper cylinders 2. The second metasurface absorbing and transmitting layer includes a first dielectric substrate 17 and four rectangular patches 3, four lumped resistors 4, four triangular patches 5, and four square rings 8 disposed on the upper surface of the first dielectric substrate 17. The third metasurface transmitting layer includes a second dielectric substrate and a square metal patch 18 disposed on the upper surface of the second dielectric substrate, with a first ring 19 and a second ring 20 etched on the square metal patch 18. The second and third metasurface absorbing and transmitting layers are arranged parallel to each other, and their centerlines are coaxial.

[0020] like Figure 1 As shown, the four copper metal cylinders 2 have the same structure, all being quarter-cylindrical structures, meaning the cross-section of the copper metal cylinder 2 is a quarter-circle cross-section; the lightning protection top layer current-guiding metal patch 1 is L-shaped; the four copper metal cylinders 2 pass through the four corner notches 10 of the second metasurface absorbing and transmitting layer and contact the upper surface of the third metasurface transmitting layer, guiding the received lightning current to the copper-clad surface of the third metasurface transmitting layer. The copper metal cylinder 2 is a quarter-cylinder of pure copper with a radius of 1mm; the length of the lightning protection top layer current-guiding metal patch 1 is 1.3mm and the width is 0.8mm.

[0021] When lightning strikes the radome, the lightning-absorbing metal patch 1 on top intercepts the lightning, preventing it from directly contacting the second and third metasurface wave-absorbing and wave-transmitting layers. The intercepted lightning is guided by the copper cylinder 2 to the pure metal surface of the third metasurface wave-transmitting layer, where it forms a discharge path, diverting the lightning to other parts and reducing damage to the radome.

[0022] like Figure 2As shown, the rectangular patch 3 is roughly rectangular in shape, with a triangular notch etched at the center of its bottom. A lumped resistor 4 is connected to each of the two corners of its bottom. Four rectangular patches 3 are arranged opposite each other and interconnected through the lumped resistors 4 to form a circle. A triangular patch 5 is positioned upwards from the rectangular patch 3, with the top of the triangular patch 5 connecting downwards to the rectangular patch 3. Two circular holes 6 are etched on the rectangular patch 3. A square ring 8 is positioned upwards from the bottom of the rectangular patch 3. The bottom edge of the square ring 8 has a first comb-shaped structure and a second comb-shaped structure respectively arranged inwards. The first comb-shaped structure includes a first rectangular strip 15 and an inwardly opening first rectangular ring 11. The inner side of the first rectangular ring 11... The first substrate 17 has three sets of first symmetrical branches 13 distributed at intervals, and three sets of first rectangular branches 7 are equally distributed on the first rectangular strip 15 extending into the first rectangular ring 11. The three sets of first symmetrical branches 13 and the three sets of first rectangular branches 7 are arranged alternately. The second comb-shaped structure includes a second rectangular strip 16 and an outwardly opening second rectangular ring 12. Three sets of second symmetrical branches 14 are equally distributed on the inner side of the second rectangular ring 12, and two sets of second rectangular branches 9 are equally distributed on the second rectangular strip 16 extending into the second rectangular ring 12. The three sets of second symmetrical branches 14 and the two sets of second rectangular branches 9 are arranged alternately. The first dielectric substrate 17 has arc-shaped notches 10 at its four corners for four copper metal cylinders 2 to pass through.

[0023] like Figure 3 As shown, the first ring 19 and the second ring 20 are concentric circles. The outer diameter of the first ring 19 is 7 mm and the inner diameter is 6.2 mm; the outer diameter of the second ring 20 is 9.5 mm and the inner diameter is 8.7 mm.

[0024] The distance between the lower surface of the second metasurface absorbing and transmitting layer and the upper surface of the third metasurface transmitting layer is set to one-quarter of the wavelength of the center frequency of the absorption band, i.e., 5 mm. This distance setting ensures that the portion of the incident wave that is not completely absorbed after passing through the second metasurface absorbing and transmitting layer is reflected back to the second metasurface absorbing and transmitting layer from the metal surface of the third metasurface transmitting layer with an opposite phase to the original phase, resulting in destructive interference and thus optimizing the absorption performance.

[0025] Both the first dielectric substrate 17 and the second dielectric substrate are Rogers RT or Duroid 5880 high-frequency microwave laminates with a relative permittivity of 2.2 and a dielectric loss tangent of 0.0009. The array unit has a size of 15.4mm × 15.4mm, and the thickness of both the first and second dielectric substrates is 1mm. The lumped resistor 4 has a resistance of 305Ω. The metal patches in the first lightning protection layer, the second metasurface absorbing and transmitting layer, and the third metasurface transmitting layer are all made of pure copper with a thickness of 0.035mm and are fabricated on the surface of the first or second dielectric substrate using PCB photolithography etching. The rectangular patch 3 has a length of 1.4mm and a width of 1mm; the triangular patch 5 is an isosceles triangle with a base of 0.5mm and a side of 0.3mm; the lumped resistor 4 has a resistance of 305Ω. The radius of the circular hole 6 is 0.2mm.

[0026] The first comb-shaped structure consists of a first rectangular strip 15, 2.8 mm long and 0.2 mm wide, and a first rectangular ring 11. The first rectangular ring is 1.7 mm long and 1.2 mm wide, and symmetrical branches 13, each 0.2 mm long and wide, are evenly distributed along the long side of the first rectangular ring. Rectangular strips protruding from the inner side of the aforementioned inward-opening rectangular ring are also evenly distributed, each 0.4 mm long and 0.15 mm wide. The second comb-shaped structure 27 consists of a rectangular strip 3.3 mm long and 0.2 mm wide, and an outward-opening rectangular ring. The rectangular ring is 2 mm long and 1.5 mm wide, and branches, each 0.2 mm long and wide, are evenly distributed along the long side of the rectangular ring in three groups, symmetrically distributed along the inner side of the long side of the rectangular ring. The rectangular ring that opens outward and inward is also filled with rectangular strips, each 0.6m long and 0.2mm wide, which are evenly distributed inside.

[0027] The first comb-shaped structure consists of a first rectangular strip 15 with a length of 2.8 mm and a width of 0.2 mm, and a first rectangular ring 11 with a length of 1.7 mm and a width of 1.2 mm; the second comb-shaped structure consists of a second rectangular strip 16 with a length of 3.3 mm and a width of 0.2 mm, and a second rectangular ring 12 with a length of 2 mm and a width of 1.5 mm.

[0028] When a mid-frequency electromagnetic wave is incident on the second absorbing and transmitting layer, the rectangular patch 3, the triangular patch 4, the square ring 8, and the first comb structure form four dipoles. The frequency operating in the second metasurface absorbing layer will oscillate along the rectangular patch 3 and be dissipated by the lumped resistance 4 through Joule heating. When a low-frequency electromagnetic wave is incident on the second absorbing and transmitting layer, the rectangular patch 3, the triangular patch 4, the square ring 8, and the second comb structure form four dipoles. The frequency operating in the second absorbing and transmitting layer will oscillate along the rectangular patch 3 and be dissipated by the lumped resistance 4 through Joule heating.

[0029] The electromagnetic waves of the high-frequency communication resonate through the square ring 8 and the first comb-shaped structure, allowing them to bypass the loss of the lumped resistance 4 and pass through the second metasurface absorbing and transmitting layer. This significantly reduces the impact of the lumped resistance 4 on the communication frequency band and lowers insertion loss. The aforementioned low-frequency and high-frequency transmitting structures allow both low-frequency and high-frequency electromagnetic waves to pass through, while the mutual coupling of the resonant structures ensures high transmittance and high selectivity of the transmitting frequency band, effectively reducing the transition band between the transmitting and absorbing frequency bands.

[0030] The square metal patch 18, the first metal ring 19, and the second metal ring 20 constitute a frequency-selective transmission resonator, enabling efficient transmission of 7.9GHz and 12GHz communication beams. Simultaneously, the copper-clad area on the surface of the second dielectric substrate serves not only as a lightning protection and current-guiding layer but also as a reflective backplate for the second metasurface wave-absorbing and wave-transmitting layer.

[0031] In this embodiment, both the first dielectric substrate 17 and the second dielectric substrate are made of Rogers RT / duroid 5880 material, with a relative permittivity of 2.2 and a dielectric loss tangent of 0.0009. The dielectric substrate material can be arbitrarily replaced with other radome dielectric substrate materials. The periodic unit size is 15.4mm × 15.4mm × 1mm. All layers use 0.035mm thick pure copper as the metal material to ensure conductivity and process stability. Figure 4 As shown, Figure 4 The red line represents the S11 parameter curve of the radome, and the green line represents the S21 parameter curve. Simulation analysis shows that the present invention exhibits an S11 reflection coefficient of less than -10dB in the 5GHz to 12.5GHz frequency band, demonstrating excellent wave absorption characteristics; and an S21 transmission coefficient greater than -2dB in the 7.7GHz to 8.4GHz and 11.4GHz to 12.6GHz frequency bands, achieving high transmittance. Through structural optimization of a three-layer metasurface unit, this invention achieves excellent lightning protection, dual-frequency communication, and broadband wave absorption functions without using traditional lightning protection strips, possessing advantages such as compact structure and high frequency selectivity.

[0032] This invention uses a first lightning protection layer to guide lightning to a third metasurface wave-transparent layer. The lightning is conducted to other locations via the metal patches of the third metasurface wave-transparent layer, thus preventing damage to the radome. The second metasurface wave-absorbing layer generates an absorption effect. Electromagnetic waves of different frequencies resonate on the second metasurface wave-absorbing layer and are absorbed. Some electromagnetic waves in the absorption frequency band are continuously reflected between the third and second metasurface wave-transparent layers and ultimately absorbed by the second metasurface wave-absorbing layer. By combining multiple resonant structures, this invention achieves wave absorption while significantly reducing the impact on the transmission frequency band, realizing broadband wave absorption functionality for low and mid frequencies.

[0033] The second metasurface absorbing and transmitting layer re-radiates electromagnetic waves in the communication frequency band, enabling them to pass through the metasurface unit. By combining a frequency-selective resonator and a wave-transmitting slotted metal, the structural size is reduced while ensuring wave transmission performance, angular stability is improved, and it is suitable for integration. Meanwhile, the surface of the third metasurface transmitting layer, being copper-clad, can also serve as the metal backing plate of the second metasurface absorbing and transmitting layer.

[0034] Through the design and performance optimization of the three-layer metasurface unit structure, this invention achieves excellent lightning protection, replacing lightning protection strips with virtually no impact on the performance of the radome. Furthermore, the substrate material can be replaced with other materials according to actual requirements. In addition, this invention achieves efficient absorption in the 5GHz to 7GHz and 8GHz to 11GHz ranges, and high transmittance at the 7.9GHz and 12GHz operating frequencies, exhibiting excellent electromagnetic wave resonance characteristics. The lightning-protected metasurface array radome provided by this invention possesses features such as lightning protection, dual-band communication, broadband absorption, high selective wave transmission, and a compact structure. It can be widely used in scenarios such as radar stealth, communication antenna integration, electromagnetic compatibility, and wireless power transmission, demonstrating promising application prospects.

[0035] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A metasurface array radome, characterized in that: The array comprises multiple identical array units arranged periodically in a tightly fitted manner, with the edges of adjacent array units seamlessly connected and sequentially connected along a preset direction. From top to bottom, each array unit comprises a first lightning protection layer, a second metasurface absorbing and transmitting layer, and a third metasurface transmitting layer. The first lightning protection layer comprises four copper metal cylinders (2) and a lightning protection top layer current-guiding metal patch (1) disposed on the top of the copper metal cylinders (2). The second metasurface absorbing and transmitting layer comprises a first dielectric substrate (17) and a layer disposed on the first dielectric substrate. (17) Four rectangular patches (3), four lumped resistors (4), four triangular patches (5) and four square rings (8) on the upper surface; the third metasurface wave-transparent layer includes a second dielectric substrate and a square metal patch (18) disposed on the upper surface of the second dielectric substrate, and a first ring (19) and a second ring (20) are etched on the square metal patch (18); the second metasurface wave-absorbing and wave-transparent layer and the third metasurface wave-transparent layer are arranged in parallel, and the center lines of the second metasurface wave-absorbing and wave-transparent layer and the third metasurface wave-transparent layer are coaxial.

2. The metasurface array radome according to claim 1, characterized in that: The four copper metal cylinders (2) have the same structure, all of which are quarter-cylindrical structures, that is, the cross-section of the copper metal cylinder (2) is a quarter-circular cross-section; the lightning protection top layer current-guiding metal patch (1) is L-shaped; the four copper metal cylinders (2) pass through the four corner notches (10) of the second metasurface wave-absorbing and wave-transmitting layer and contact the upper surface of the third metasurface wave-transmitting layer, guiding the lightning current to the copper-clad surface of the third metasurface wave-transmitting layer.

3. The metasurface array radome according to claim 1, characterized in that: The rectangular patch (3) is roughly rectangular in shape, with a triangular notch etched at the center of its bottom. A lumped resistor (4) is connected to each of the two corners of its bottom. The four rectangular patches (3) are arranged opposite each other and connected to each other through the lumped resistors (4) to form a circle. A triangular patch (5) is set upward on the rectangular patch (3). The top of the triangular patch (5) is connected downward to the rectangular patch (3). Two round holes (6) are etched on the rectangular patch (3). A square ring (8) is set upward on the bottom of the rectangular patch (3). The bottom edge of the square ring (8) is respectively provided with a first comb structure and a second comb structure. The first comb structure includes a first rectangular strip (15) and an inwardly opening first rectangular ring (11). The inner side of the first rectangular ring (11) is equidistantly distributed. There are three sets of first symmetrical branches (13), and three sets of first rectangular branches (7) are equidistantly distributed on the first rectangular strip (15) extending into the first rectangular ring (11). The three sets of first symmetrical branches (13) and the three sets of first rectangular branches (7) are arranged alternately. The second comb-shaped structure includes a second rectangular strip (16) and an outwardly opening second rectangular ring (12). Three sets of second symmetrical branches (14) are equidistantly distributed on the inner side of the second rectangular ring (12). Two sets of second rectangular branches (9) are equidistantly distributed on the second rectangular strip (16) extending into the second rectangular ring (12). The three sets of second symmetrical branches (14) and the two sets of second rectangular branches (9) are arranged alternately. The four corners of the first dielectric substrate (17) are provided with arc-shaped notches (10) for four copper metal cylinders (2) to pass through.

4. The metasurface array radome according to claim 1, characterized in that: The first ring (19) and the second ring (20) are concentric circles. The outer diameter of the first ring (19) is 7 mm and the inner diameter is 6.2 mm. The outer diameter of the second ring (20) is 9.5 mm and the inner diameter is 8.7 mm.

5. The metasurface array radome according to claim 1, characterized in that: The distance between the lower surface of the second metasurface absorbing and transmitting layer and the upper surface of the third metasurface transmitting layer is set to one-quarter of the wavelength of the center frequency of the absorption band, i.e., 5 mm.

6. The metasurface array radome according to claim 1, characterized in that: The first dielectric substrate (17) and the second dielectric substrate are both made of Rogers RT or Duroid 5880 high-frequency microwave laminate with a relative permittivity of 2.2 and a dielectric loss tangent of 0.0009. The size of the array unit is 15.4mm × 15.4mm, and the thickness of the first dielectric substrate (17) and the second dielectric substrate is 1mm.

7. The metasurface array radome according to claim 1, characterized in that: The resistance of the lumped resistor (4) is 305Ω. The metal patches in the first lightning protection layer, the second metasurface absorbing and transmitting layer and the third metasurface transmitting layer are all made of pure copper with a thickness of 0.035mm, and are made on the surface of the first dielectric substrate (17) or the second dielectric substrate by PCB photolithography etching process.

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