Low-scattering array based on integration of absorption and transmission integrated metasurface and Vivaldi antenna

Abstract

The invention relates to a low-scattering array based on integration of a absorption and transmission integrated metasurface and a Vivaldi antenna, the low-scattering array is composed of N * N units, and each unit comprises a loss layer, an antenna radiator, an air layer between the antenna radiator and the loss layer, and a floor. The loss layer takes a dielectric plate as a substrate, resonators are printed on the upper surface and the lower surface of the dielectric plate, and each resonator is formed by sequentially rotating 90 degrees, 180 degrees and 270 degrees along the anticlockwise or clockwise direction by taking the center of the square dielectric plate as a rotating center and positioning. The antenna radiator takes a dielectric plate as a substrate, a first surface of the dielectric plate is printed with a metal patch of a radiation structure, a second surface of the dielectric plate is printed with a feed network composed of an impedance conversion microstrip line and a fan-shaped microstrip line which are connected in sequence, and the floor is a metal plate with a rectangular gap. According to the metasurface and antenna integrated structure, the bandwidth of the metasurface and antenna integrated structure is greatly widened while out-of-band scattering reduction is achieved, the low-profile characteristic is shown, and the actual application requirement of a broadband antenna system is met.

Description

Technical Field

[0001] This invention belongs to the fields of communication, electromagnetic field and microwave technology, and relates to a low-scattering array based on an integrated metasurface that absorbs light and a Vivaldi antenna, which can be used in many broadband systems with low scattering requirements, such as radar antennas and communication antennas. Background Technology

[0002] As a primary source of radar scattering, the stealth design of radar antenna systems is crucial for reducing radar cross section (RCS). Antenna stealth technologies mainly include three methods: time domain, spatial domain, and frequency domain. Among these, frequency domain stealth is the most widely used, particularly through frequency selective surface (FSS) radomes to achieve effective reflection of out-of-band incident waves. However, in engineering design, metasurfaces are often designed independently from the antenna, which reduces space utilization and leads to degraded antenna performance.

[0003] To address the issues of degraded radiation and scattering performance and low space utilization in low-scattering antenna systems caused by separate antenna and metasurface designs, researchers typically integrate polarized rotating metasurfaces with slot antennas, or integrate FSS and microstrip antennas into a single antenna array to achieve monocentric RCS reduction over a wider bandwidth.

[0004] However, FSS can only reduce the RCS of a single-station radar, and its stealth effect on bistatic or multistatic radar is limited. Frequency Selective Rasorbers (FSRs), which integrate penetration, can reduce the RCS outside the operating band while ensuring friendly communication, and are suitable for both single- and bistatic radar systems. Regarding the integrated design of antennas and FSRs, in 2024, Cao Qunsheng et al. published an article titled "An Integrated Antenna Array With Broadband, Low-RCS, and High-Gain Characteristics" in IEEE Transactions on Antennas and Propagation, proposing a low-RCS integrated structure based on FSA. The integrated structure's FSA consists of two layers: an upper frequency-selective absorber and a lower microstrip patch radiator. By adjusting the size of the bottom patch to form a checkerboard structure, the in-band RCS of the antenna is reduced, while simultaneously achieving RCS reduction both inside and outside the band. However, the antenna's operating band is only 5–5.77 GHz, making it difficult to apply to broadband radar antenna systems.

[0005] Therefore, the integrated design of a transmissive metasurface and a broadband antenna to achieve RCS reduction in single-station and bi-station antenna systems while retaining broadband radiation characteristics remains an urgent problem to be solved, and is of great significance for the low-scattering design of many broadband systems such as radar antennas and communication antennas. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies and address the issues of narrow operating frequency range and high cross-section in current metasurface and antenna integrated systems, this invention aims to propose a low-scattering array based on the integration of a penetration-absorbing metasurface and a Vivaldi antenna. The goal is to achieve reduced RCS in both monostatic and bistatic antenna systems while retaining broadband radiation characteristics through integrated design of the penetration-absorbing metasurface and broadband antenna, thereby meeting the stealth requirements of broadband antenna systems.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A low-scattering array based on a penetration-absorbing metasurface integrated with a Vivaldi antenna, comprising N × N elements, each element including a loss layer, an antenna radiator, an air layer between the antenna radiator and the loss layer, and a ground plane. The loss layer and the ground plane constitute a penetration-absorbing metasurface, and the antenna radiator and the ground plane constitute a broadband antenna. The array is characterized by: The antenna radiator is a Vivaldi antenna, including a radiating patch printed on the first surface of the antenna dielectric substrate. The two sides of the center line of the radiating patch are respectively formed by a first exponentially graded slot line and a second exponentially graded slot line with different curvatures to form a double radiating arm. The beginning of the first exponentially graded slot line and the second exponentially graded slot line are respectively engraved with circular grooves and the end is a cross-toe coupling gap. The feed network is disposed on the second surface of the antenna dielectric substrate.

[0008] In one embodiment, the loss layer includes resonators symmetrically printed on the upper and lower surfaces of a first dielectric substrate, the first dielectric substrate being perpendicular to the antenna dielectric substrate; the resonators are composed of sub-units with 0° as the reference, which are rotated 90°, 180°, and 270° sequentially in a counterclockwise or clockwise direction with the center of the first dielectric substrate as the rotation center.

[0009] In one embodiment, the subunit includes a long strip metal patch, a short rectangular metal patch, a chip resistor, and a long rectangular metal patch; The long metal patch is a bent metal strip structure formed along a right-angle bending path, with its starting center located at a reference 0°. The short rectangular metal patch connects to the end of the long metal patch, with its center on the central symmetry line of the first dielectric substrate, and its length direction perpendicular to the central symmetry line of the first dielectric substrate. The long rectangular metal patch and the short rectangular metal patch are connected through the patch resistor. The center of the long rectangular metal patch is on the central symmetry line of the first dielectric substrate, and its length direction is perpendicular to the central symmetry line of the first dielectric substrate.

[0010] In one embodiment, the resistance value of the chip resistor is R, where 200Ω ≤ R ≤ 800Ω.

[0011] In one embodiment, the floor is a metal plate with rectangular slots, parallel to the first dielectric substrate of the loss layer.

[0012] In one embodiment, the curvature of the first exponentially gradient slot line is less than the curvature of the second exponentially gradient slot line, the first exponentially gradient slot line is closer to the center line of the radiating patch, and the second exponentially gradient slot line is farther away from the center line of the radiating patch. Two first exponential gradient slots are distributed on both sides of the center line of the radiating patch to form a first exponential gradient slot. The beginning of the first exponential gradient slot is connected to the first circular slot through a rectangular slot. Four second-index gradient slot lines are distributed on both sides of the center line of the radiating patch, forming two symmetrical second-index gradient slots. The beginning of each second-index gradient slot is connected to a second circular slot. The radius of the first circular groove is greater than the radius of the second circular groove.

[0013] In one embodiment, the curvatures of the first exponentially gradient slotted line and the second exponentially gradient slotted line are VR1 and VR2, respectively, 0.1 ≤ VR1 ≤ 0.8, 0.8 ≤ VR2 ≤ 1.8, and VR1 and VR2 do not both take the value of 0.8.

[0014] In one embodiment, the feed network includes an impedance transformation microstrip line and a sector microstrip line connected in sequence. The beginning of the impedance transformation microstrip line is connected to the center of the sector microstrip line, and the end is connected to the lumped port of the antenna element.

[0015] In one embodiment, the impedance transformation microstrip line consists of three segments connected in sequence, wherein the second segment is an L-shaped structure bent at 90°.

[0016] In one embodiment, the radius of the sector microstrip line is r3, the central angle is deg, 0.8mm ≤ r3 ≤ 2mm, and 60° ≤ deg < 180°.

[0017] Compared with existing technologies, this invention achieves an integrated design of a penetration-absorbing metasurface and a broadband antenna, aiming to reduce the RCS of the antenna system in both monostatic and bistatic configurations while retaining its broadband radiation characteristics. Its specific beneficial effects are described below: 1. Effectively expands the operating bandwidth of the integrated metasurface and antenna structure. This invention uses a Vivaldi antenna as the antenna radiator and fully considers the coupling effect between the antenna radiator and the integrated metasurface, thereby expanding the operating bandwidth of the integrated metasurface and antenna structure. Simulation results show that this invention achieves wideband operation of the integrated metasurface and antenna structure. 2. Effectively reduces the overall cross-section of the integrated metasurface and antenna structure. This invention uses two exponentially gradient slotted lines with different curvatures to form dual radiating arms, creating a tightly coupled structure to reduce the antenna cross-section. It also introduces a toe coupling structure to expand the bandwidth. The integrated metasurface loss layer and the antenna radiator share a common ground plane, further reducing the overall cross-section of the unit and improving the integrability of this invention. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0019] Figure 2 This is a schematic diagram of the unit structure of the present invention.

[0020] Figure 3 This is a schematic diagram of the overall structure of the antenna radiator of the unit of the present invention.

[0021] Figure 4 This is a schematic diagram of the antenna radiating patch structure of the unit of the present invention.

[0022] Figure 5 This is a schematic diagram of the planar structure of a resonator in the loss layer of the unit of the present invention.

[0023] Figure 6 This is a three-dimensional structural diagram of a resonator in the loss layer of the unit of the present invention. Figure 5 Axonometric view.

[0024] Figure 7 This is a schematic diagram of the sub-unit structure of the loss layer resonator of the present invention.

[0025] Figure 8 This is a schematic diagram of the structure of the first metal strip group of the loss layer resonator of the present invention.

[0026] Figure 9 This is a schematic diagram of the structure of the second metal strip group of the loss layer resonator of the present invention.

[0027] Figure 10This is a schematic diagram of the power supply network structure of the unit of the present invention.

[0028] Figure 11 This is the active voltage standing wave ratio curve of the present invention under equal amplitude and in-phase excitation at all ports.

[0029] Figure 12 This is a single-station scattering curve of the array of the present invention under cross-polarized wave incident conditions. Detailed Implementation

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

[0031] As a primary source of radar scattering, the stealth design of radar antenna systems is crucial for reducing the radar cross-section (RCS) of equipment. Conventional stealth frequency-selective cladding can only reduce the single-station RCS, which is insufficient to meet stealth requirements. Furthermore, separating the frequency-selective metasurface and antenna design leads to deterioration of the antenna system's radiation and scattering performance and reduced space utilization. Therefore, the integrated design of a penetration-absorbing metasurface and antenna has become a research hotspot in the stealth field. However, in existing technologies, the integrated structure has a narrow bandwidth and a high profile, which contradicts the development trend of broadband operation and structural integration in airborne radar antenna systems. Therefore, there is an objective application demand for the integrated design of a broadband, low-profile penetration-absorbing metasurface and antenna.

[0032] In response to the above-mentioned situation, this invention has conducted research and design, and proposes a low-scattering array based on the integration of a transmissive metasurface and a Vivaldi antenna.

[0033] This invention relates to a low-scattering array based on an integrated absorber metasurface and a Vivaldi antenna. (See also...) Figure 1 It consists of N × N periodically arranged units (N=4), and each unit has a square structure. See also Figure 2 Each unit comprises a loss layer, an antenna radiator, an air layer between the antenna radiator and the loss layer, and a ground plane 4. The loss layer and the ground plane 4 form a permeable metasurface, and the antenna radiator and the ground plane 4 form a broadband antenna.

[0034] See Figure 3 and Figure 4 The antenna radiator of the present invention is a Vivaldi antenna, which uses an antenna dielectric substrate 3 as a base. Radiation patches 71 are printed on the antenna dielectric substrate 3 in a regular arrangement as antenna radiators. Specifically, the radiation patches 71 are printed on the first surface of the antenna dielectric substrate 3, and the second surface of the antenna dielectric substrate 3 is printed with a feed network 72. The ground plane 4 is a metal plate with a rectangular gap.

[0035] The Vivaldi antenna of the present invention has two radiating arms formed on both sides of the center line of the radiating patch 71 by two exponentially tapered slots with different curvatures—namely, the first exponentially tapered slot 711 and the second exponentially tapered slot 712. The beginnings of the two exponentially tapered slots are respectively engraved with corresponding circular slots, and the ends of the two radiating arms are interdigitated coupling slots 713.

[0036] Based on the above structure, this invention addresses the requirements of low scattering and compact design for many broadband systems such as radar and communication antennas. To achieve RCS reduction in monostatic and bistatic antenna systems while retaining broadband radiation characteristics, the array structure of this invention employs a penetration-absorbing integrated metasurface and Vivaldi antenna integration design to achieve in-band broadband radiation. By utilizing the shared ground plane between the penetration-absorbing integrated metasurface's absorbing loss layer and the antenna, the overall cross-section of the penetration-absorbing integrated metasurface and antenna integrated structure is reduced, achieving miniaturization and improving integration density. In particular, for the antenna radiating body, a structure similar to a dipole radiating arm is constructed by etching two types of exponential slots, reducing the antenna cross-section, and sufficient capacitive coupling is introduced using the toe coupling slot 713 to achieve broadband radiation. Simulation results show that this invention can achieve good periodicity within a limited space, retaining broadband radiation characteristics while achieving RCS reduction, greatly broadening the bandwidth of the metasurface and antenna integrated structure, and reducing the overall cross-section.

[0037] Furthermore, in this invention, the two different curvatures refer to the fact that the curvature of the first exponentially gradient slot line 711 is less than the curvature of the second exponentially gradient slot line 712. The first exponentially gradient slot line 711 is closer to the center line of the radiating patch 71, while the second exponentially gradient slot line 712 is farther from the center line of the radiating patch 71. It is easy to understand that "closer" and "farther" here are relative concepts. The first exponentially gradient slot line 711 consists of two slot lines on either side of the first exponentially gradient slot. The first exponentially gradient slot is formed by two symmetrical first exponentially gradient slot lines 711 distributed on both sides of the center line of the radiating patch 71. The beginning of the first exponentially gradient slot is connected to the first circular slot through a rectangular slot. Correspondingly, the second exponentially gradient slot is formed by two second exponentially gradient slot lines 712. There are two second exponentially gradient slots, symmetrically distributed on both sides of the first exponentially gradient slot. The beginning of each second exponentially gradient slot is connected to a second circular slot; the radius of the second circular slot is smaller than the radius of the first circular slot.

[0038] Furthermore, such as Figure 5 and Figure 6As shown, the loss layer of the present invention uses a first dielectric substrate 1 as a base, and resonators 2 are printed on both the upper and lower surfaces, with the two layers of resonators 2 being symmetrically projected. The first dielectric substrate 1 is preferably square, perpendicular to the antenna dielectric substrate 3, and parallel to the ground plane 4. Each resonator 2 is composed of a sub-unit 31 with 0° as the reference, and is positioned by rotating 90°, 180°, and 270° sequentially in a counterclockwise or clockwise direction with the center of the first dielectric substrate 1 as the rotation center.

[0039] See Figure 7 Each subunit 31 includes a long strip metal patch 311, a short rectangular metal patch 312, a chip resistor 313, and a long rectangular metal patch 314. The center of the rectangular side at the beginning of the long strip metal patch 311 is located at a reference 0°. The long strip metal patch 311 is a bent metal strip structure formed along a right-angle bending path. The short rectangular metal patch 312 is located at the end of the long strip metal patch 311, and its center is on the central symmetry line of the first dielectric substrate 1. Its length direction is perpendicular to the central symmetry line of the first dielectric substrate 1. The long rectangular metal patch 314 and the short rectangular metal patch 312 are connected through the chip resistor 313. The center of the long rectangular metal patch 314 is on the central symmetry line of the first dielectric substrate 1, and its length direction is perpendicular to the central symmetry line of the first dielectric substrate 1. The metal strips printed on the upper surface of the first dielectric substrate 1 are called the first metal strip group. Figure 8 A schematic diagram of the first metal strip group of the loss layer resonator. The metal strips printed on the lower surface of the first dielectric substrate 1 are referred to as the second metal strip group. Figure 9 A schematic diagram of the structure of the second metal strip group of the loss layer resonator.

[0040] According to the above design, the loss layer of the present invention utilizes a bent metal strip structure, which increases the equivalent electrical length of the loss layer while reducing the unit size, thereby achieving miniaturization.

[0041] Furthermore, the feed network 72 of the present invention is disposed on the second surface of the antenna dielectric substrate 3, including an impedance transformation microstrip line 722 and a fan-shaped microstrip line 721 connected in sequence. The impedance transformation microstrip line 722 is composed of three segments connected in sequence. The first segment is connected at the center of the fan-shaped microstrip line 721, the second segment is an L-shaped structure bent at 90°, and the end of the third segment is the end of the impedance transformation microstrip line 722, which is connected to a rectangular lumped port. The antenna radiator and the ground plane together constitute a broadband antenna. See [reference needed]. Figure 10 The width of the first segment is less than the width of the second segment, and the width of the second segment is less than the width of the third segment.

[0042] In one parameter design of the loss layer of the present invention, the first dielectric substrate 1 has a side length of a, a = 12 mm, a thickness of h, h = 0.8 mm, and a relative permittivity of 2.2. The width of the elongated metal patch 311 is w, w = 0.2 mm. The width of the short rectangular metal patch 312 is w1, and the length is L1, w1 = 0.2 mm, L1 = 0.6 mm. The width of the long rectangular metal patch 314 is w2, and the length is L2, w2 = 0.4 mm, L2 = 2 mm. The resistance of the chip resistor 313 is R, R = 600 Ω.

[0043] The present invention discloses a parameter design for an antenna radiator. The antenna dielectric substrate 3 has dimensions of m × n, where m = 12 mm, n = 13.5 mm, thickness h1, h = 0.3 mm, and dielectric constant 4.4. The curvatures of the first exponentially graded slot line 711 and the second exponentially graded slot line 712 are VR1 and VR2, respectively, where VR1 = 0.4 and VR2 = 1.3. The radii of the first circular slot and the second circular slot are r1 and r2, respectively, where r1 = 2.2 mm and r2 = 0.5 mm. The width of the interdigitated coupling slot 713 is w3, where w3 = 0.2 mm. The radius of the fan-shaped microstrip line 721 is r3, and the central angle is deg, where r3 = 1.2 mm and deg = 150°.

[0044] The present invention discloses a parameter design for the power supply network 72, wherein the widths of the first, second, and third segments of the impedance transformation microstrip line 722 are mw1, mw2, and mw3, respectively, where mw1 = 0.1 mm, mw2 = 0.2 mm, and mw3 = 0.5 mm. The rectangular lumped port dimensions at the end of the impedance transformation microstrip line 722 are e × f, where e = 0.3 mm and f = 0.5 mm.

[0045] The floor 4 of the present invention is designed with the following parameters: it is a square with a side length of a1, and the rectangular gap cut on the floor 4 has a size of c × d, where a1 = 12 mm, c = 0.5 mm, and d = 0.7 mm.

[0046] The technical effects of the present invention will be further explained below with reference to simulation experiments: Simulation conditions and content: The array monostatic scattering under active voltage standing wave ratio and cross-polarized plane wave incidence was simulated and calculated using the commercial simulation software ANSYS 2024 R1. The results are as follows: Figure 11 and Figure 12 As shown.

[0047] Simulation Result Analysis: Figure 11 This is a graph showing the active voltage standing wave ratio (VSWR) of the array under equal amplitude and in-phase excitation at all ports of the present invention. Figure 11The horizontal axis represents frequency, and the vertical axis represents the active voltage standing wave ratio (VSWR). The VSWR curves for different ports are distinguished by curves marked with different symbols. Figure 11 As can be seen, the active voltage standing wave ratio of all ports in this invention is less than 2.5 in the frequency range of 8 to 14 GHz, realizing broadband radiation and greatly expanding the bandwidth of the metasurface and antenna integrated structure.

[0048] Figure 12 This is a single-station scattering curve of the array of the present invention under cross-polarized wave incident conditions. Figure 12 In the graph, the horizontal axis represents frequency, and the vertical axis represents monostatic scattering. The curves marked with squares are the monostatic scattering curves of the antenna array after removing the loss layer, under cross-polarized wave incidence. The curves marked with circles are the monostatic scattering curves of the array under cross-polarized wave incidence. Figure 12 As can be seen, the antenna and metasurface integrated array of the present invention achieves a single-station scattering reduction of more than 5 dB in the frequency range of 2 ~ 8 GHz and 12.5 ~ 14.0 GHz compared with the antenna array without metasurface under cross-polarized wave incident conditions.

[0049] The simulation results above show that the present invention can have good periodicity within a limited space, can retain broadband radiation characteristics while achieving RCS reduction, greatly broadens the bandwidth of the metasurface and antenna integrated structure, and exhibits low profile characteristics, thus meeting the practical application needs of broadband antenna systems.

[0050] In summary, this invention is a low-scattering array based on an integrated metasurface and Vivaldi antenna, which can reduce the RCS of the antenna system while retaining broadband radiation characteristics to meet the stealth requirements of broadband antenna systems. It consists of N × N units (N=4), each unit including a loss layer, an antenna radiator, an air layer between the antenna radiator and the loss layer, and a ground plane. The loss layer is based on a dielectric substrate, with resonators printed on both the upper and lower surfaces. Each resonator is composed of a sub-unit with 0° as the reference, rotated 90°, 180°, and 270° counterclockwise or clockwise around the center of the square dielectric substrate. The antenna radiator is also based on the dielectric substrate, with a metal patch of the radiating structure printed on the first surface and a feed network composed of sequentially connected impedance-transformer microstrip lines and fan-shaped microstrip lines printed on the second surface. The ground plane is a metal plate with a rectangular slot. This invention significantly broadens the bandwidth of the metasurface and antenna integration structure and exhibits low-profile characteristics, meeting the practical application needs of broadband antenna systems.

[0051] The above description is merely an embodiment of the present invention and does not constitute any limitation on the present invention. Obviously, those skilled in the art, after understanding the content and principles of the present invention, may make various modifications and changes in form and details without departing from the principles and structure of the present invention. However, these modifications and changes based on the ideas of the present invention are still within the protection scope of the claims of the present invention.

Claims

1. A low-scattering array based on a penetration-absorbing metasurface integrated with a Vivaldi antenna, comprising N × N units, each unit including a loss layer, an antenna radiator, an air layer between the antenna radiator and the loss layer, and a ground plane (4), wherein the loss layer and the ground plane (4) constitute a penetration-absorbing metasurface, and the antenna radiator and the ground plane (4) constitute a broadband antenna, characterized in that: The antenna radiator is a Vivaldi antenna, including a radiating patch (71) printed on the first surface of the antenna dielectric substrate (3). The two sides of the center line of the radiating patch (71) are respectively formed by a first exponentially gradient slot line (711) and a second exponentially gradient slot line (712) with different curvatures. The beginning of the first exponentially gradient slot line (711) and the second exponentially gradient slot line (712) are respectively engraved with circular grooves, and the end is a cross-toe coupling gap (713). The feed network (72) is disposed on the second surface of the antenna dielectric substrate (3).

2. The low-scattering array based on the integrated penetration-absorbing metasurface and Vivaldi antenna as described in claim 1, characterized in that: The loss layer includes resonators (2) symmetrically printed on the upper and lower surfaces of the first dielectric substrate (1), the first dielectric substrate (1) being perpendicular to the antenna dielectric substrate (3); the resonator (2) is composed of sub-units (31) with 0° as the reference, which are rotated 90°, 180° and 270° in a counterclockwise or clockwise direction with the center of the first dielectric substrate (1) as the rotation center.

3. The low-scattering array based on the integrated penetration-absorbing metasurface and Vivaldi antenna as described in claim 2, characterized in that: The subunit (31) includes a long strip metal patch (311), a short rectangular metal patch (312), a chip resistor (313), and a long rectangular metal patch (314). The long strip metal patch (311) is a bent metal strip structure formed along a right-angle bending path, with its starting center located at reference 0°. The short rectangular metal patch (312) is connected to the end of the long strip metal patch (311), with its center on the central symmetry line of the first dielectric substrate (1), and its length direction is perpendicular to the central symmetry line of the first dielectric substrate (1). The long rectangular metal patch (314) and the short rectangular metal patch (312) are connected through the patch resistor (313). The center of the long rectangular metal patch (314) is on the central symmetry line of the first dielectric substrate (1), and its length direction is perpendicular to the central symmetry line of the first dielectric substrate (1).

4. The low-scattering array based on the integrated penetration-absorbing metasurface and Vivaldi antenna as described in claim 3, characterized in that: The resistance of the chip resistor (313) is R, 200Ω ≤ R ≤ 800Ω.

5. The low-scattering array based on the integration of a penetration-absorbing metasurface and a Vivaldi antenna according to claim 1, characterized in that: The floor (4) is a metal plate with a rectangular gap, parallel to the first dielectric substrate (1) of the loss layer.

6. The low-scattering array based on the integration of a penetration-absorbing metasurface and a Vivaldi antenna according to claim 1, characterized in that: The curvature of the first exponentially gradient slotted line (711) is less than the curvature of the second exponentially gradient slotted line (712). The first exponentially gradient slotted line (711) is closer to the center line of the radiating patch (71), and the second exponentially gradient slotted line (712) is farther away from the center line of the radiating patch (71). Two first exponential gradient slot lines (711) are distributed on both sides of the center line of the radiating patch (71) to form a first exponential gradient slot. The beginning of the first exponential gradient slot is connected to the first circular slot through a rectangular slot. Four second-index gradient slot lines (712) are distributed on both sides of the center line of the radiation patch (71), forming two symmetrical second-index gradient slots. The beginning of each second-index gradient slot is connected to a second circular slot. The radius of the first circular groove is greater than the radius of the second circular groove.

7. The low-scattering array based on the integration of a penetration-absorbing metasurface and a Vivaldi antenna according to claim 1 or 6, characterized in that: The curvatures of the first exponentially gradient slotted line (711) and the second exponentially gradient slotted line (712) are VR1 and VR2, respectively, 0.1 ≤ VR1 ≤ 0.8, 0.8 ≤ VR2 ≤ 1.8, and VR1 and VR2 do not both take the value of 0.

8.

8. The low-scattering array based on the integration of a penetration-absorbing metasurface and a Vivaldi antenna according to claim 1 or 6, characterized in that: The feed network (72) includes an impedance transformation microstrip line (722) and a fan-shaped microstrip line (721) connected in sequence. The beginning of the impedance transformation microstrip line (722) is connected to the center of the fan-shaped microstrip line (721), and the end is connected to the lumped port of the antenna element.

9. The low-scattering array based on the integration of a penetration-absorbing metasurface and a Vivaldi antenna according to claim 8, characterized in that: The impedance transformation microstrip line (722) consists of three segments connected in sequence, the second segment being an L-shaped structure bent at 90°.

10. The low-scattering array based on the integration of a penetration-absorbing metasurface and a Vivaldi antenna according to claim 8 or 9, characterized in that: The radius of the fan-shaped microstrip line (721) is r3, the central angle is deg, 0.8mm ≤ r3 ≤ 2 mm, and 60° ≤ deg < 180°.

Images