A broadband high-gain 5g base station antenna based on metasurface

Abstract

The application relates to a broadband high-gain 5G base station antenna based on a metasurface, which comprises a system floor, a first low-frequency auxiliary unit, a second low-frequency auxiliary unit, a first high-frequency auxiliary unit, a second high-frequency auxiliary unit, a central unit and a feed network; the first low-frequency auxiliary unit, the second low-frequency auxiliary unit, the first high-frequency auxiliary unit and the second high-frequency auxiliary unit are array-distributed on a first surface of the system floor and surround the central unit; the central unit comprises a metasurface layer and a dual-polarization unit, the dual-polarization unit is arranged on the first surface of the system floor, and the metasurface layer is fixed on the dual-polarization unit; the feed network is arranged on a second surface of the system floor and is connected with the first low-frequency auxiliary unit, the second low-frequency auxiliary unit, the first high-frequency auxiliary unit, the second high-frequency auxiliary unit and the central unit through coaxial lines respectively. The antenna has the advantages of wide frequency band, high average gain, high aperture efficiency and high isolation.

Description

Technical Field

[0001] This invention belongs to the field of communication technology, specifically relating to a broadband high-gain 5G base station antenna based on metasurface. Background Technology

[0002] With the rapid development of 5G communication technology, countries around the world are accelerating the construction of 5G networks. 5G technology has gradually become one of the key technologies driving the intelligent era, the Internet of Things, and big data applications. 5G networks not only far surpass previous generations in speed, but their low latency and large connection capacity also make them promising for applications in autonomous driving, the industrial internet, and smart cities. To achieve efficient operation of 5G communication, base station antennas, as a core component of the wireless communication system, play a crucial role.

[0003] The performance of base station antennas directly impacts the signal coverage, transmission rate, connection stability, and network capacity of 5G networks. In 5G systems, spectrum resources are increasingly scarce, necessitating base station antennas with higher bandwidth, stronger gain, and more efficient beam control capabilities to cope with higher density device connections and more complex environmental challenges. While traditional antenna design methods perform well in some applications, they have limitations in terms of gain, bandwidth, and directivity at high frequencies. Especially in the high-frequency bands used in 5G network deployments, traditional antennas face a series of problems, including insufficient gain, narrow bandwidth, large size, and low power efficiency, making it difficult to meet the demands of high-performance 5G networks.

[0004] In January 2024, Y.-F. Lin, C.-C. Chang, C.-H. Chen, J.-Y. Xie, Y.-X.Zhuang, and H.-M. Chen proposed a dual-polarized spline-Loop antenna array suitable for 5G base stations in their paper "Dual-Polarized Spline-Loop Antenna Array With TiltAngle Radiation for 5G Base Stations." While this array partially meets the requirements of high-performance 5G networks, its operating bandwidth is only 2.74-3.91 GHz (21.1%), failing to fully cover the entire 5G-NR frequency band. This bandwidth limitation will impact data transmission rates and communication capacity when dealing with the ever-expanding spectrum resources and diverse application scenarios of future 5G networks. Furthermore, the antenna array has low gain and an aperture efficiency of only 30.306%, far below industrial application levels, potentially affecting the overall layout and cost-effectiveness of base stations.

[0005] In recent years, metasurface technology, as an emerging electromagnetic wave control technology, has been increasingly applied in antenna design. A metasurface is an artificially designed material or structure that can precisely adjust the propagation characteristics of electromagnetic waves, offering extremely high flexibility and functionality. By optimizing the geometry, material composition, and structural properties of metasurfaces, functions such as beamforming, gain enhancement, and bandwidth expansion can be achieved. These characteristics make metasurfaces an ideal choice for improving the performance of 5G base station antennas.

[0006] Patent CN119133857A discloses a dual-band common-aperture base station antenna array, which utilizes a composite decoupling structure to reduce high- and low-frequency interference. However, the antenna port isolation remains unsatisfactory, only reaching 15 dB within the 3.5-5.0 GHz operating frequency band. Furthermore, the antenna array exhibits low gain, averaging 11.5 dBi, and an aperture efficiency of only 24.879%. This results in a smaller coverage area and insufficient signal strength at the same radiated power. In base station construction, this may necessitate increasing the number of antennas or raising the transmit power to compensate, thereby increasing construction and operating costs. Moreover, in space-constrained base station environments, it can negatively impact the overall layout and resource utilization.

[0007] The patent with publication number CN110911805A discloses a miniaturized dual-band dual-polarization 5G base station antenna with high isolation and high harmonic suppression. It achieves high isolation and harmonic suppression by using a unique resonant patch, coupling slot and harmonic suppression stub design. However, the operating frequency band is narrow and only supports a small number of 5G-NR frequency bands. It cannot provide comprehensive support when facing diverse communication needs.

[0008] Patent CN106876982A discloses a metasurface for improving the performance of multi-antenna systems and a multi-antenna system using a metasurface. The metasurface design achieves certain results in reducing inter-antenna coupling, improving antenna gain, and increasing matching bandwidth, and can be applied to various antennas and communication systems. However, this solution has shortcomings in meeting the specific requirements of 5G base station antennas, failing to fully satisfy the high-efficiency signal transmission requirements of 5G base stations in specific frequency bands; furthermore, the metasurface design does not prioritize miniaturization, which will limit its practical application in space-constrained 5G base station deployment scenarios.

[0009] In summary, existing antennas suffer from drawbacks such as narrow operating frequency bands, low antenna gain, low aperture efficiency, and low isolation. Summary of the Invention

[0010] To address the aforementioned problems in the prior art, this invention provides a broadband high-gain 5G base station antenna based on a metasurface. The technical problem to be solved by this invention is achieved through the following technical solution:

[0011] This invention provides a broadband high-gain 5G base station antenna based on a metasurface, comprising: a system floor, a first low-frequency auxiliary unit, a second low-frequency auxiliary unit, a first high-frequency auxiliary unit, a second high-frequency auxiliary unit, a center unit, and a feed network, wherein...

[0012] The first low-frequency auxiliary unit, the second low-frequency auxiliary unit, the first high-frequency auxiliary unit, and the second high-frequency auxiliary unit are arranged in an array on the first surface of the system floor and surround the central unit. The first low-frequency auxiliary unit and the second low-frequency auxiliary unit are diagonally distributed, and the first high-frequency auxiliary unit and the second high-frequency auxiliary unit are diagonally distributed.

[0013] The central unit includes a metasurface layer and a dual-polarization unit, wherein the dual-polarization unit is disposed on the first surface of the system floor and the metasurface layer is fixed on the dual-polarization unit;

[0014] The power supply network is disposed on the second surface of the system floor and is connected to the first low-frequency auxiliary unit, the second low-frequency auxiliary unit, the first high-frequency auxiliary unit, the second high-frequency auxiliary unit and the central unit respectively via coaxial lines.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] The antenna of this invention achieves a wide operating frequency band by setting a metasurface layer in the central unit, which can integrate and utilize 5G-NR frequency band resources, ensuring seamless network connectivity and improving communication reliability and universality. It utilizes the electromagnetic properties of the metasurface to achieve high antenna gain and high aperture efficiency, enabling focused and enhanced signal transmission. At the same transmit power, the signal propagates further and with greater intensity, while achieving high aperture efficiency with a small area, reducing energy waste and scattering. The cross-array design, with low-frequency auxiliary units and high-frequency auxiliary units diagonally distributed, ensures high isolation, allowing signals to operate independently when multiple antennas are in operation, avoiding interference, and improving system capacity and reliability. Attached Figure Description

[0017] Figure 1 A three-dimensional structural schematic diagram of a broadband high-gain 5G base station antenna based on a metasurface provided in an embodiment of the present invention;

[0018] Figure 2 This is a three-dimensional structural diagram of the central unit provided in an embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of the planar structure of the metasurface layer in the central unit provided in an embodiment of the present invention;

[0020] Figures 4a-4cThis is a schematic diagram of a cross-shaped patch in a metasurface layer provided in an embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram of the three-dimensional structure of the dual-polarization unit in the central unit provided in an embodiment of the present invention;

[0022] Figure 6 This is a schematic diagram of the planar structure of the first reflective layer in the dual-polarization unit provided in an embodiment of the present invention;

[0023] Figure 7 This is a schematic diagram of the structure of the first feed balun in the dual-polarization unit provided in an embodiment of the present invention;

[0024] Figure 8 This is a three-dimensional structural diagram of the low-frequency auxiliary unit provided in an embodiment of the present invention;

[0025] Figure 9 This is a schematic diagram of the planar structure of the second reflective layer in the low-frequency auxiliary unit provided in an embodiment of the present invention;

[0026] Figure 10 This is a schematic diagram of the structure of the second feed balun in the low-frequency auxiliary unit provided in an embodiment of the present invention;

[0027] Figure 11 This is a three-dimensional structural diagram of the high-frequency auxiliary unit provided in an embodiment of the present invention;

[0028] Figure 12 This is a schematic diagram of the planar structure of the third reflective layer in the high-frequency auxiliary unit provided in an embodiment of the present invention;

[0029] Figure 13 This is a schematic diagram of the structure of the third feed balun in the high-frequency auxiliary unit provided in an embodiment of the present invention;

[0030] Figure 14 A schematic plan view of the power supply network provided in an embodiment of the present invention;

[0031] Figure 15 A side view of the broadband high-gain 5G base station antenna based on metasurface provided in an embodiment of the present invention;

[0032] Figure 16 This is a graph showing the antenna reflection coefficient of the present invention.

[0033] Figure 17 This is a graph showing the antenna port isolation of the present invention.

[0034] Figure 18 This is a graph showing the antenna gain of the present invention.

[0035] Figure 19 The radiation pattern of the antenna of this invention at a frequency of 3.6 GHz with Phi=90 is shown.

[0036] Figure 20 The radiation pattern of the antenna of this invention at the frequency of 3.6 GHz with Phi=0 is shown.

[0037] Figure 21 The radiation pattern of the antenna of this invention at a frequency of 4.8 GHz with Phi=90 is shown.

[0038] Figure 22 This is the radiation pattern of the antenna of the present invention at the frequency of 4.8 GHz with Phi=0. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0040] Example 1

[0041] Please see Figure 1 , Figure 1 This is a three-dimensional structural diagram of a broadband high-gain 5G base station antenna based on a metasurface, provided in an embodiment of the present invention.

[0042] This embodiment of the broadband high-gain 5G base station antenna based on metasurface includes a system floor 1, a first low-frequency auxiliary unit 2, a second low-frequency auxiliary unit 3, a first high-frequency auxiliary unit 4, a second high-frequency auxiliary unit 5, a central unit 6, and a feed network 7.

[0043] The first low-frequency auxiliary unit 2, the second low-frequency auxiliary unit 3, the first high-frequency auxiliary unit 4, and the second high-frequency auxiliary unit 5 are arranged in an array on the first surface of the system floor 1 and surround the central unit 6. The first low-frequency auxiliary unit 2 and the second low-frequency auxiliary unit 3 are arranged diagonally, as are the first high-frequency auxiliary unit 4 and the second high-frequency auxiliary unit 5. The central unit 6 includes a metasurface layer 61 and a dual-polarization unit. The dual-polarization unit is disposed on the first surface of the system floor 1, and the metasurface layer 61 is fixed on the dual-polarization unit. The power supply network 7 is disposed on the second surface of the system floor 1 and is connected to the microstrip power supply lines of the first low-frequency auxiliary unit 2, the second low-frequency auxiliary unit 3, the first high-frequency auxiliary unit 4, the second high-frequency auxiliary unit 5, and the central unit 6 respectively via coaxial lines.

[0044] Specifically, the first low-frequency auxiliary unit 2, the second low-frequency auxiliary unit 3, the first high-frequency auxiliary unit 4, and the second high-frequency auxiliary unit 5 are all fixed to the first surface of the system floor 1 via inserts, forming a 2×2 array. The first low-frequency auxiliary unit 2 and the second low-frequency auxiliary unit 3 are located on one diagonal of the array, and the first high-frequency auxiliary unit 4 and the second high-frequency auxiliary unit 5 are located on the other diagonal of the array. The central unit 6 is located at the center of the array. The power supply network 7 is printed on a dielectric substrate, which is fixed to the second surface of the system floor 1, and the printed power supply network 7 is located away from the second surface of the system floor 1. The first low-frequency auxiliary unit 2, the second low-frequency auxiliary unit 3, the first high-frequency auxiliary unit 4, and the second high-frequency auxiliary unit 5 are respectively connected to the power supply network 7 via coaxial lines penetrating the system floor.

[0045] In this embodiment of the invention, the first surface and the second surface are two opposing surfaces.

[0046] Specifically, the frequency bands of the first low-frequency auxiliary unit 2 and the second low-frequency auxiliary unit 3 are 3-4GHz, and the frequency bands of the first high-frequency auxiliary unit 4 and the second high-frequency auxiliary unit 5 are 4-5GHz. After forming an array, the frequency bands of all units are optimized to 3.3-5GHz, and the wavelength range corresponding to 3.3-5GHz is 60-90.9mm.

[0047] Specifically, in the first low-frequency auxiliary unit 2, the second low-frequency auxiliary unit 3, the first high-frequency auxiliary unit 4, and the second high-frequency auxiliary unit 5, the distance between the centers of two adjacent auxiliary units is 0.6 times the wavelength, and the distance between the center of each auxiliary unit and the center of the central unit 6 is 0.75 times the wavelength.

[0048] In this embodiment, the spacing between the centers of two adjacent auxiliary units is 0.6 times the wavelength, which effectively avoids grating lobes and ensures that the signal is mainly concentrated in the main lobe direction, improving signal directivity and energy concentration. The distance between the center of each auxiliary antenna and the center of the central unit 6 is 0.75 times the wavelength, used to adjust the electromagnetic coupling strength between the antenna unit and the central part, so that the mutual coupling between the low-frequency auxiliary antenna and the high-frequency auxiliary antenna is within a suitable range, avoiding signal interference caused by excessive coupling. At the same time, a certain coupling effect is used to optimize the performance of the entire antenna, thereby increasing bandwidth and improving signal stability.

[0049] This embodiment effectively increases bandwidth and reduces coupling interference between antenna elements by combining auxiliary antennas of different frequency bands, positioning the central element, and optimizing the spacing between elements.

[0050] Please see Figure 2 , Figure 2This is a three-dimensional structural diagram of the central unit provided in an embodiment of the present invention. The central unit 6 includes a metasurface layer 61 and a dual-polarization unit. The dual-polarization unit is disposed on the first surface of the system floor 1, and the metasurface layer 61 is fixed on the dual-polarization unit.

[0051] Specifically, the metasurface layer 61 is fixed directly above the dual-polarization unit by four long nylon studs 64, and the dual-polarization unit is fixed in the center of the system floor 1 by inserts.

[0052] Please see Figure 3 , Figure 3 This is a schematic diagram of the planar structure of the metasurface layer in the central unit provided in an embodiment of the present invention. The metasurface layer 61 includes a first dielectric substrate 611 and a plurality of cross-shaped patches 612, wherein the plurality of cross-shaped patches 612 are distributed in a cross array on the surface of the first dielectric substrate 611 away from the system floor 1. Exemplarily, the metasurface layer 61 is formed by the first dielectric substrate 611 and a 3×5 cross-shaped patch 612 in a cross array.

[0053] Please see Figures 4a-4c , Figures 4a-4c This is a schematic diagram of a cross-shaped patch in a metasurface layer provided in an embodiment of the present invention, wherein... Figure 4a This is a schematic diagram of the cross-shaped patch. Figure 4b This is a schematic diagram of the equivalent circuit of a cross-shaped surface mount device. Figure 4c for Figure 4b The circuit diagram represented by the square brackets.

[0054] Please see Figure 4a Each cross-shaped patch 612 is formed by a solid cross-shaped patch 6121 and four hollow symmetrical M-shaped patches 6122 connected to the four branch ends of the solid cross-shaped patch 6121. Each hollow symmetrical M-shaped patch 6122 has two mirror-symmetrical M-shaped units. Each M-shaped unit is formed by multiple bends of a microstrip line with a bending angle of 90°.

[0055] Please see Figure 4b and Figure 4c In the solid cross-shaped patch 6121, each branch is equivalent to an inductor, and the four branches can be equivalent to four inductors (L1, L2, L3, L4). In each M-shaped cell, the sub-microstrip line ML extending along the branches of the solid cross-shaped patch 6121 is equivalent to an inductor, and the blank portion between two sub-microstrip lines ML is equivalent to a capacitor, such as... Figure 4c As shown, Figure 4c for Figure 4bThe equivalent circuits between C1 and L4, L1 and C2, L2 and C3, and L3 and C4 are the same as those between C1 and L4. The blank areas between the two M-shaped units without surface mounts are equivalent to capacitors (C1, C2, C3, C4). The complete equivalent circuit of the entire hollowed-out symmetrical M-shaped surface mount 6122 is a capacitor (C5) and an inductor (L5) connected in series.

[0056] Please see Figure 5 , Figure 5 This is a three-dimensional structural diagram of the dual-polarization unit in the central unit provided in an embodiment of the present invention. The dual-polarization unit includes a first reflective layer 62 and a first feed balun 63, wherein the metasurface layer 61 is fixed to one side of the first reflective layer 62 by a plurality of long nylon studs 64; the first feed balun 63 is disposed on the other side of the first reflective layer 62 and fixed to the system floor 1 by inserts; the first feed balun 63 is connected to the feed network 7 by a coaxial line passing through the system floor 1.

[0057] Please see Figure 6 , Figure 6 This is a schematic diagram of the planar structure of the first reflective layer in a dual-polarization unit provided in an embodiment of the present invention. The first reflective layer 62 includes a second dielectric substrate 621 and four spindle-shaped patches 622, wherein the four spindle-shaped patches 622 are centrally symmetrically disposed on the surface of the second dielectric substrate 621 away from the system ground plane 1; each spindle-shaped patch 622 includes a first straight line segment 6221 and two first smooth curve segments 6222, the two first smooth curve segments 6222 extending from the two ends of the first straight line segment 6221 until they intersect to form a closed axisymmetric shape; the first straight line segments 6221 of the four spindle-shaped patches 622 are close to each other and opposite each other. It can be understood that in each spindle-shaped patch, the two ends of the first straight line segment 6221 are respectively connected to the ends of the two first smooth curve segments 6222, and the other ends of the two first smooth curve segments 6222 intersect, and the intersection is away from the center of the second dielectric substrate 621.

[0058] For example, Figure 6 In the first straight segment 6221, the second dielectric substrate 621 is square with a width W1 of 35 mm, the length W2 of the first straight segment 6221 is 3.25 mm, and the dimension W3 of the first smooth curve segment 6222 is 12.48 mm.

[0059] In this embodiment, four spindle-shaped patches are disposed on the second dielectric substrate to form a first reflective layer. The four spindle-shaped patches are the main electromagnetic radiation and reflection structures of the first reflective layer. The spindle shape and central symmetry layout can affect the amplitude and phase of the reflected signal, and perform targeted reflection of signals with different polarization directions to achieve optimized reflection of dual-polarized signals and improve the performance of the dual-polarization unit.

[0060] Please see Figure 7 , Figure 7 This is a schematic diagram of the structure of the first feed balun in the dual-polarization unit provided in an embodiment of the present invention. The first feed balun 63 includes a first central feed component 631 and a second central feed component 632 that are spatially perpendicularly intersecting.

[0061] The first central power supply assembly 631 includes a third dielectric substrate 6311, a first microstrip power supply line 6312, a first parasitic patch 6313, and a second parasitic patch 6314. The third dielectric substrate 6311 is fixed to the system floor 1 by inserts. The first microstrip power supply line 6312 is disposed on the first surface of the third dielectric substrate 6311 and connected to the power supply network 7 by a coaxial line. The first parasitic patch 6313 and the second parasitic patch 6314 are symmetrically distributed on the second surface of the third dielectric substrate 6311.

[0062] The second center-feed assembly 632 includes a fourth dielectric substrate 6321, a second microstrip feed line 6322, a third parasitic patch 6323, and a fourth parasitic patch 6324. The fourth dielectric substrate 6321 is fixed to the system ground plane 1 by inserts. The second microstrip feed line 6322 is disposed on the first surface of the fourth dielectric substrate 6321 and connected to the feed network 7 via a coaxial line. The third parasitic patch 6323 and the fourth parasitic patch 6324 are symmetrically distributed on the second surface of the fourth dielectric substrate 6321. The first microstrip feed line 6312 and the second microstrip feed line 6322 form an electromagnetic coupling structure in the intersection area, constituting the feed network of the dual-polarization unit.

[0063] Specifically, both the third dielectric substrate 6311 and the fourth dielectric substrate 6321 have two protrusions on their tops for insertion into the first reflective layer 62 to fix the first feeding balun 63. The third dielectric substrate 6311 has a gap at its bottom, and the fourth dielectric substrate 6321 has a gap at its top. The two dielectric substrates are inserted into their respective gaps, so that the planes on which the two dielectric substrates are located are orthogonal to each other.

[0064] Specifically, the first microstrip feed line 6312 is formed by connecting three microstrip lines a1, b1, and c1 with successively increasing widths. Microstrip lines a1 and b1 have lateral bending sections, and microstrip line c1 is used to connect to the coaxial line. The second microstrip feed line 6322 is formed by connecting three microstrip lines a2, b2, and c2 with successively increasing widths. Microstrip lines a2 and b2 have lateral bending sections, and microstrip line c2 is used to connect to the coaxial line. The height of the second microstrip feed line 6322 is less than the height of the first microstrip feed line 6312, so that the second microstrip feed line 6322 and the first microstrip feed line 6312 do not contact each other and form an electromagnetic coupling structure in the intersection area, together constituting the feed network of the dual-polarization unit.

[0065] Please see Figure 8 , Figure 8 This is a three-dimensional structural diagram of the low-frequency auxiliary unit provided in an embodiment of the present invention. The first low-frequency auxiliary unit 2 and the second low-frequency auxiliary unit 3 have the same structure, both including a second reflective layer 21 and a second feed balun 22 fixed between the second reflective layer 21 and the system floor 1. Specifically, the second feed balun 22 is fixed to the system floor 1 by inserts, and the second reflective layer 21 is fixed to the second feed balun 22.

[0066] Please see Figure 9 , Figure 9 This is a schematic diagram of the planar structure of the second reflective layer in the low-frequency auxiliary unit provided in an embodiment of the present invention. The second reflective layer 21 includes a fifth dielectric substrate 211, a hollow rhomboid patch 212, and four nested willow-leaf-shaped patches 213; the hollow rhomboid patch 212 and the four nested willow-leaf-shaped patches 213 are disposed on the surface of the fifth dielectric substrate 211 away from the system floor 1; the four nested willow-leaf-shaped patches 213 are centrally symmetrically arranged and located inside the hollow rhomboid patch 212; each nested willow-leaf-shaped patch 213 includes a nested inner ring 2131 and an outer ring 2132, and the inner ring 2131 and the outer ring 2132 have the same shape.

[0067] Specifically, the hollow rhombus patch 212 is located at the center of the entire structure. The outer ring of the nested willow leaf patch 213 is located inside the hollow rhombus patch 212 and is adjacent to it; the inner ring 2131 is located inside the outer ring 2132 and is a distance away from the outer ring 2132. From the overall layout, with the hollow rhombus patch 212 as the center, inwardly there are the outer ring 2132 of the nested willow leaf patch 213 and the inner ring 2131 of the nested willow leaf patch 213.

[0068] Furthermore, the outer ring 2132 includes a second straight line segment 21321 and two second smooth curve segments 21322. The two smooth curve segments 21322 extend from the two ends of the second straight line segment 21321 until they intersect at the inner corner of the hollow rhombus patch 212, forming a closed axisymmetric figure. The second straight line segments 21321 of the four outer rings 2132 are close to each other and opposite each other. The inner ring 2131 includes a third straight line segment 21311 and two third smooth curve segments 21312. The two smooth curve segments 21312 extend from the two ends of the third straight line segment 21311 until they intersect, forming a closed axisymmetric figure; the third straight line segments 21311 of the four inner rings 2131 are parallel to the second straight line segments 21321 of the corresponding outer rings.

[0069] For example, the fifth dielectric substrate 211 is square with a width W4 of 35 mm, the second straight segment 21321 of the outer ring 2132 in the nested willow leaf-shaped patch 213 has a length W5 of 3.25 mm, the second smooth curve segment 21322 has a size W6 of 13.51 mm, and the hollow rhombus patch 212 has a width W7 of 23 mm.

[0070] The second reflective layer in this embodiment includes a hollow rhombus patch and four nested willow leaf patches. The hollow rhombus patch and the nested willow leaf patches can enhance the radiation efficiency of the antenna and adjust the reflection characteristics of electromagnetic waves.

[0071] Please see Figure 10 , Figure 10 This is a schematic diagram of the structure of the second feed balun in the low-frequency auxiliary unit provided in an embodiment of the present invention. The second feed balun 22 includes a first low-frequency feed assembly 221 and a second low-frequency feed assembly 222 that are spatially perpendicularly intersecting. The first low-frequency feed assembly 221 includes a sixth dielectric substrate 2211, a third microstrip feed line 2212, a fifth parasitic patch 2213, and a sixth parasitic patch 2214; the sixth dielectric substrate 2211 is fixed to the system floor 1 by inserts, the third microstrip feed line 2212 is disposed on the first surface of the sixth dielectric substrate 2211 and connected to the feed network 7 by a coaxial line, and the fifth parasitic patch 2213 and the sixth parasitic patch 2214 are symmetrically distributed on the second surface of the sixth dielectric substrate 2211. The second low-frequency feed assembly 222 includes a seventh dielectric substrate 2221, a fourth microstrip feed line 2222, a seventh parasitic patch 2223, and an eighth parasitic patch 2224. The seventh dielectric substrate 2221 is fixed to the system ground plane 1 by inserts. The fourth microstrip feed line 2222 is disposed on the first surface of the seventh dielectric substrate 2221 and connected to the feed network 7 via a coaxial line. The seventh parasitic patch 2223 and the eighth parasitic patch 2224 are symmetrically distributed on the second surface of the seventh dielectric substrate 2221. The third microstrip feed line 2212 and the fourth microstrip feed line 2222 form an electromagnetic coupling structure in the intersection area, together constituting the radiation network of the low-frequency auxiliary unit.

[0072] Specifically, both the sixth dielectric substrate 2211 and the seventh dielectric substrate 2221 have two protrusions on their tops for insertion into the second reflective layer 21 to fix the second feed balun 22. The sixth dielectric substrate 2211 has a gap at its bottom, and the seventh dielectric substrate 2221 has a gap at its top. The two dielectric substrates are inserted into their respective gaps, so that the planes on which the two dielectric substrates are located are orthogonal to each other.

[0073] Specifically, the third microstrip feed line 2212 is formed by connecting three microstrip lines a3, b3, and c3 with successively increasing widths. Microstrip lines a3 and b3 have lateral bending sections, and microstrip line c3 is used to connect to the coaxial line. The fourth microstrip feed line 2222 is formed by connecting three microstrip lines a4, b4, and c4 with successively increasing widths. Microstrip lines a4 and b4 have lateral bending sections, and microstrip line c4 is used to connect to the coaxial line. The height of the fourth microstrip feed line 2222 is less than the height of the third microstrip feed line 2212, so that the fourth microstrip feed line 2222 and the third microstrip feed line 2212 do not contact each other and form an electromagnetic coupling structure in the intersection area, together constituting a radiation network.

[0074] In this embodiment, the fifth, sixth, seventh, and eighth parasitic patches interact with the main radiating structure (hollow rhombus patch and nested willow leaf patch) to improve impedance matching, increase bandwidth, and adjust the radiation direction. The third and fourth microstrip feed lines effectively transmit external radio frequency energy to the radiating structure (hollow rhombus patch and nested willow leaf patch) of the antenna element, ensuring that the energy can accurately excite the antenna element to generate the required electromagnetic radiation. At the same time, they participate in impedance matching adjustment to a certain extent, reduce energy reflection, and improve energy transmission efficiency.

[0075] Please see Figure 11 , Figure 11 This is a three-dimensional structural diagram of the high-frequency auxiliary unit provided in an embodiment of the present invention. The first high-frequency auxiliary unit 4 and the second high-frequency auxiliary unit 5 have the same structure, both including a third reflective layer 41 and a third feed balun 42 fixedly disposed between the third reflective layer 41 and the system floor 1. Specifically, the third feed balun 42 is fixed to the system floor 1 by inserts, and the third reflective layer 41 is fixed to the third feed balun 42.

[0076] Please see Figure 12 , Figure 12 This is a schematic diagram of the planar structure of the third reflective layer in the high-frequency auxiliary unit provided in an embodiment of the present invention. The third reflective layer 41 includes an eighth dielectric substrate 411 and four windmill blade-shaped patches 412, which are centrally symmetrically disposed on the surface of the eighth dielectric substrate 411.

[0077] For example, four windmill blade-shaped patches 412 are arranged in pairs opposite each other on the same straight line and located on the diagonal of the eighth dielectric substrate 411, with an included angle of 90° between the center lines of two adjacent windmill blade-shaped patches 412. The ends of the four windmill blade-shaped patches 412 that are close to each other are all provided with a 45° chamfer. The eighth dielectric substrate 411 is square in shape, with a width W8 of 34 mm. Each windmill blade-shaped patch 412 has a length W9 of 17 mm and a width W10 of 4.2 mm.

[0078] In this embodiment, the four windmill-blade-shaped patches interact with the surrounding electromagnetic field, determining the radiation characteristics of the antenna element and achieving effective radiation and reception of high-frequency signals.

[0079] Please see Figure 13 , Figure 13 This is a schematic diagram of the structure of the third feed balun in the high-frequency auxiliary unit provided in an embodiment of the present invention. The third feed balun 42 includes a first high-frequency feed assembly 421 and a second high-frequency feed assembly 422 that are spatially perpendicularly intersecting. The first high-frequency feed assembly 421 includes a ninth dielectric substrate 4211, a fifth microstrip feed line 4212, a ninth parasitic patch 4213, and a tenth parasitic patch 4214; the ninth dielectric substrate 4211 is fixed to the system ground plane 1 by inserts, the fifth microstrip feed line 4212 is disposed on the first surface of the ninth dielectric substrate 4211 and connected to the feed network 7 by a coaxial line, and the ninth parasitic patch 4213 and the tenth parasitic patch 4214 are symmetrically distributed on the second surface of the ninth dielectric substrate 4211. The second high-frequency power supply assembly 422 includes a tenth dielectric substrate 4221, a sixth microstrip feed line 4222, an eleventh parasitic patch 4223, and a twelfth parasitic patch 4224. The tenth dielectric substrate 4221 is fixed to the system ground plane 1 by inserts. The sixth microstrip feed line 4222 is disposed on the first surface of the tenth dielectric substrate 4221 and connected to the power supply network 7 via a coaxial line. The eleventh parasitic patch 4223 and the twelfth parasitic patch 4224 are symmetrically distributed on the second surface of the tenth dielectric substrate 4221. The fifth microstrip feed line 4212 and the sixth microstrip feed line 4222 form an electromagnetic coupling structure in the intersection area, constituting the power supply network of the high-frequency auxiliary unit.

[0080] Specifically, a gap is provided at the bottom of the ninth dielectric substrate 4211 and a gap is provided at the top of the tenth dielectric substrate 4221. The two dielectric substrates are inserted into the corresponding gaps, so that the planes on which the two dielectric substrates are located are orthogonal to each other, forming a vertical cross structure. Thus, the two dielectric substrates and the microstrip feed lines and parasitic patches on them constitute a spatially orthogonal radiation and feeding network, thereby realizing the directional transmission and impedance matching function of high-frequency signals.

[0081] Specifically, the fifth microstrip feeder 4212 is formed by connecting three microstrip lines a5, b5, and c5, with microstrip line a5 having a lateral bend, and microstrip line c5 used to connect to the coaxial line. The sixth microstrip feeder 4222 is formed by connecting three microstrip lines a6, b6, and c6, with microstrip line a6 having a lateral bend, and microstrip line c6 used to connect to the coaxial line. The lateral bends of the fifth microstrip feeder 4212 and the sixth microstrip feeder 4222 are interleaved, so that the fifth microstrip feeder 4212 and the sixth microstrip feeder 4222 do not contact each other and form an electromagnetic coupling structure in the intersection area, together constituting the feeder network.

[0082] Specifically, the ninth parasitic patch 4213 and the tenth parasitic patch 4214 form opposite L-shapes and each has a protrusion at the top; the eleventh parasitic patch 4223 and the twelfth parasitic patch 4224 form opposite L-shapes and each has a protrusion at the top. The third feed balun 42 is fixed by inserting the four protrusions into the third reflective layer 41.

[0083] The ninth, tenth, eleventh, and twelfth parasitic patches in this embodiment can serve as auxiliary radiators, coupled with the main radiating element (windmill blade-shaped patch), to change the current distribution of the antenna element, increase the operating bandwidth, and improve matching performance.

[0084] Please see Figure 14 , Figure 14 This is a schematic plan view of a power supply network provided in an embodiment of the present invention. The power supply network 7 includes a first sub-network 71 and a second sub-network 72. The first sub-network 71 is used to connect microstrip feed lines with a first polarization angle, including a first Wilkinson power divider WPD1, a second Wilkinson power divider WPD2, a first T-type power divider T1, and a second T-type power divider T2. The input terminal of the first Wilkinson power divider WPD1 serves as the first external port P1 of the feed network 7, the first output terminal is connected to the input terminal of the second Wilkinson power divider WPD2, and the second output terminal is connected to the input terminal of the first T-type power divider T1. The first output terminal of the first T-type power divider T1 serves as the first output port H1 of the feed network 7, and the second output terminal is connected to the input terminal of the second T-type power divider T2. The first and second output terminals of the second T-type power divider T2 serve as the second output port H2 and the third output port H3 of the feed network 7, respectively. The first and second output terminals of the second Wilkinson power divider WPD2 serve as the fourth output port H4 and the fifth output port H5 of the feed network 7, respectively.

[0085] The second sub-network 72 is used to connect microstrip feed lines with a second polarization angle, including a third Wilkinson power divider WPD3, a fourth Wilkinson power divider WPD4, a third T-type power divider T3, and a fourth T-type power divider T4; the input terminal of the third Wilkinson power divider WPD3 serves as the second external port P2 of the feed network 7, the first output terminal is connected to the input terminal of the fourth Wilkinson power divider WPD4, and the second output terminal is connected to the input terminal of the third T-type power divider T3; the first output terminal of the third T-type power divider T3 serves as the sixth output port H6 of the feed network 7, and the second output terminal is connected to the input terminal of the fourth T-type power divider T4; the first and second output terminals of the fourth T-type power divider T4 serve as the seventh output port H7 and the eighth output port H8 of the feed network 7, respectively; the first and second output terminals of the fourth Wilkinson power divider WPD4 serve as the ninth output port H9 and the tenth output port H10 of the feed network 7, respectively.

[0086] The central unit 6 is connected to the first output port H1 and the sixth output port H6 via two coaxial cables; the first low-frequency auxiliary unit 2 is connected to the second output port H2 and the seventh output port H7 via two coaxial cables; the second low-frequency auxiliary unit 3 is connected to the third output port H3 and the eighth output port H8 via two coaxial cables; the first high-frequency auxiliary unit 4 is connected to the fourth output port H4 and the ninth output port H9 via two coaxial cables; and the second high-frequency auxiliary unit 5 is connected to the fifth output port H5 and the tenth output port H10 via two coaxial cables.

[0087] Please see Figure 15 , Figure 15 This is a side view of the broadband high-gain 5G base station antenna based on a metasurface according to an embodiment of the present invention. The central unit 6 has coaxial lines 11a and 11b, the first low-frequency auxiliary unit 2 has coaxial lines 11c and 11d, the second low-frequency auxiliary unit 3 has coaxial lines 11e and 11f, the first high-frequency auxiliary unit 4 has coaxial lines 11g and 11h, and the second high-frequency auxiliary unit 5 has coaxial lines 11i and 11j. Each coaxial line has an inner conductor, an isolation layer, and an outer conductor. All coaxial lines pass through the system floor 1, and the outer conductors of all coaxial lines are connected to the system floor 1, while the inner conductors are connected to the output port of the feed network 7.

[0088] It should be noted that the first output port H1, the second output port H2, the third output port H3, the fourth output port H4, and the fifth output port H5 of the first sub-network 71 are connected to microstrip feed lines with a first polarization angle, and the sixth output port H6, the seventh output port H7, the eighth output port H8, the ninth output port H9, and the tenth output port H10 of the second sub-network 72 are connected to microstrip feed lines with a second polarization angle. For example, the microstrip feed lines in the first low-frequency auxiliary unit 2, the second low-frequency auxiliary unit 3, the first high-frequency auxiliary unit 4, the second high-frequency auxiliary unit 5, and the central unit 6 are all dual-polarized microstrip feed lines, one with a polarization angle of +45° and the other with a polarization angle of -45°. Then, the output ports of the first sub-network 71 are all connected to the microstrip feed line with a polarization angle of +45°, and the output ports of the second sub-network 72 are all connected to the microstrip feed line with a polarization angle of -45°. Alternatively, the output ports of the first sub-network 71 are all connected to the microstrip feed line with a polarization angle of -45°, and the output ports of the second sub-network 72 are all connected to the microstrip feed line with a polarization angle of +45°.

[0089] Specifically, in the central unit 6, the polarization angle of the first microstrip feed line 6312 of the first feed balun 63 is +45° and the polarization angle of the second microstrip feed line 6322 is -45°. The inner conductor of the coaxial line 11a is connected to the bottom of the first microstrip feed line 6312 and passes through the system floor 1 to connect to the first output port H1 of the feed network 7; the inner conductor of the coaxial line 11b is connected to the bottom of the second microstrip feed line 6322 and passes through the system floor 1 to connect to the sixth output port H6 of the feed network 7.

[0090] In the first low-frequency auxiliary unit 2, the polarization angle of the third microstrip feed line 2212 of the second feed balun 22 is +45° and the polarization angle of the fourth microstrip feed line 2222 is -45°. The inner conductor of the coaxial line 11c is connected to the bottom of the third microstrip feed line 2212 and passes through the system floor 1 to connect to the second output port H2 of the feed network 7. The inner conductor of the coaxial line 11d is connected to the bottom of the fourth microstrip feed line 2222 and passes through the system floor 1 to connect to the seventh output port H7 of the feed network 7.

[0091] In the second low-frequency auxiliary unit 3, the inner conductor of coaxial line 11e is connected to the bottom of the microstrip feed line with a polarization angle of +45° in the second low-frequency auxiliary unit 3, and passes through the system floor 1 to connect to the third output port H3 of the feed network 7; the inner conductor of coaxial line 11f is connected to the bottom of the microstrip feed line with a polarization angle of -45° in the second low-frequency auxiliary unit 3, and passes through the system floor 1 to connect to the eighth output port H8 of the feed network 7.

[0092] In the first high-frequency auxiliary unit 4, the polarization angle of the fifth microstrip feed line 4212 of the third feed balun 42 is +45° and the polarization angle of the sixth microstrip feed line 4222 is -45°. The inner conductor of the coaxial line 11g is connected to the bottom of the fifth microstrip feed line 4212 and passes through the system floor 1 to connect to the fourth output port H4 of the feed network 7; the inner conductor of the coaxial line 11h is connected to the bottom of the sixth microstrip feed line 4222 and passes through the system floor 1 to connect to the ninth output port H9 of the feed network 7.

[0093] In the second high-frequency auxiliary unit 5, the inner conductor of coaxial line 11i is connected to the bottom of the microstrip feed line with a polarization angle of +45° in the second high-frequency auxiliary unit 5, and passes through the system floor 1 to connect to the fifth output port H5 of the feed network 7; the inner conductor of coaxial line 11j is connected to the bottom of the microstrip feed line with a polarization angle of -45° in the second high-frequency auxiliary unit 5, and passes through the system floor 1 to connect to the tenth output port H10 of the feed network 7.

[0094] In the antenna array of this invention, P1 and P2 are external ports of the antenna array, which can be external input ports or external output ports.

[0095] In this embodiment, the system floor 1 is made of aluminum. The first dielectric substrate 611, the second dielectric substrate 621, the third dielectric substrate 6311, the fourth dielectric substrate 6321, the fifth dielectric substrate 211, the sixth dielectric substrate 2211, the seventh dielectric substrate 2221, the eighth dielectric substrate 411, the ninth dielectric substrate 4211, and the tenth dielectric substrate 4221 are all made of FR-4 material. The relative permittivity of FR-4 material is 4.3, the dielectric loss is 0.016, and the thickness of each substrate is 0.8 mm. The characteristic impedance of the coaxial cable is 50 ohms.

[0096] The following section describes the effect of the broadband high-gain 5G base station antenna based on metasurface in this embodiment, based on simulation results.

[0097] Please see Figure 16 , Figure 16 This is a graph showing the antenna reflection coefficient of the present invention, where |S 11 |S represents the reflection coefficient of antenna port P1, which operates in the frequency band of 3.3GHz-5.0GHz; 22 | represents the reflection coefficient of antenna port P2, which operates in the frequency band of 3.3 GHz to 5.0 GHz.

[0098] Figure 16 In terms of operating bandwidth, the relative bandwidth of the antenna described in this invention is 40.96%.

[0099] The relative bandwidth of the antenna proposed in the article "Dual-Polarized Spline-Loop Antenna Array With Tilt AngleRadiation for 5G Base Stations" by Y.-F. Lin, C.-C. Chang, C.-H. Chen, J.-Y. Xie, Y.-X. Zhuang, and H.-M. Chen is 35.19%. In comparison, the relative bandwidth of the antenna described in this invention is increased by 16.39%.

[0100] Compared to the antenna proposed in CN119133857A, which has a relative bandwidth of 21.1%, the antenna of this invention has a relative bandwidth that is 89.57% higher and can cover the N77 (3.3GHz-4.2GHz), N78 (3.3GHz-3.8GHz), and N79 (4.4GHz-5.0GHz) frequency bands of 5G-NR.

[0101] Compared to the antenna proposed in CN106876982A, which has an operating bandwidth of 8.9%, the antenna described in this invention has an operating bandwidth that is 360.22% higher and can cover the N77 (3.3GHz-4.2GHz), N78 (3.3GHz-3.8GHz), and N79 (4.4GHz-5.0GHz) frequency bands of 5G-NR.

[0102] Please see Figure 17 , Figure 17 This is a graph showing the antenna port isolation of the present invention, where |S 21 | is the forward transmission coefficient from antenna port P1 to port P2. Obviously, in the operating frequency band of 3.3GHz-5.0GHz, the isolation between port P1 and port P2 is less than -20.78dB.

[0103] The article "Dual-Polarized Spline-Loop Antenna Array With Tilt AngleRadiation for 5G Base Stations" by Y.-F. Lin, C.-C. Chang, C.-H. Chen, J.-Y. Xie, Y.-X. Zhuang, and H.-M. Chen describes an antenna with an isolation of 15 dB. In comparison, the antenna described in this invention achieves an isolation improvement of 38.53%.

[0104] Compared to the antenna proposed in CN119133857A, which has an isolation of 15dB, the antenna of this invention has an improved isolation of 38.53%.

[0105] Please see Figure 18 , Figure 18 This is a graph showing the antenna gain of the present invention. Figure 18 Regarding antenna gain, the antenna described in this invention has an average gain of 13.76 dBi in the 3.3 GHz-5.0 GHz frequency band.

[0106] The average gain of the antenna proposed in the article "Dual-Polarized Spline-Loop Antenna Array With Tilt AngleRadiation for 5G Base Stations" by Y.-F. Lin, C.-C. Chang, C.-H. Chen, J.-Y. Xie, Y.-X. Zhuang, and H.-M. Chen is 11 dBi. In comparison, the average gain of the antenna described in this invention is improved by 38.53%.

[0107] The average gain of the prior art CN119133857A is 11.5dBi. In comparison, the average gain of the antenna of the present invention is increased by 20%, and the peak gain reaches 15.64dBi (at 4.0GHz).

[0108] The average gain of the prior art CN106876982A is 6.5dBi. In comparison, the average gain of the antenna of the present invention is increased by 111.69%, and the peak gain reaches 15.64dBi (at 4.0GHz).

[0109] Regarding aperture efficiency, the aperture efficiency of the antenna described in this invention is 74.33% according to the formula.

[0110] The aperture efficiency of the antenna proposed in the article "Dual-Polarized Spline-Loop Antenna Array With Tilt AngleRadiation for 5G Base Stations" by Y.-F. Lin, C.-C. Chang, C.-H. Chen, J.-Y. Xie, Y.-X. Zhuang, and H.-M. Chen is 25.56%. In comparison, the aperture efficiency of the antenna described in this invention is improved by approximately 190.73%.

[0111] Compared to the aperture efficiency of CN119133857A (24.879%), the aperture efficiency of the antenna of this invention is improved by approximately 198.77%.

[0112] Since the antenna size of the comparative scheme CN106876982A is not explicitly given, it is estimated to be about 30mm×60mm based on the relevant description and actual application scenario. The aperture efficiency calculated from this is 66%. In comparison, the aperture efficiency of the antenna of the present invention is improved by about 12.64%.

[0113] The comparison results of the broadband high-gain 5G base station antenna based on metasurface in this embodiment with the articles "Dual-PolarizedSpline-Loop Antenna Array With Tilt Angle Radiation for 5G Base Stations" by Y.-F. Lin, C.-C. Chang, C.-H. Chen, J.-Y. Xie, Y.-X. Zhuang, and H.-M. Chen, CN119133857A, and CN106876982A are shown in Tables 1, 2, and 3.

[0114] Table 1

[0115]

[0116] Table 2

[0117]

[0118] Table 3

[0119]

[0120] As can be seen from Tables 1, 2 and 3, the antenna in this embodiment has the advantages of wide operating frequency band, high average gain, high aperture efficiency and high isolation.

[0121] Please see Figure 19 , Figure 19 The image shows the radiation pattern of the antenna of this invention at a frequency of 3.6 GHz with Phi=90°, where Phi is the angle, Theta is the horizontal angle unit, deg is the vertical angle unit, and dBi is the gain unit. The main lobe in the image is clear and prominent, exhibiting good energy concentration, which is beneficial for directional signal transmission. The sidelobe levels are low, effectively suppressing interference in other directions. The radiation pattern shape is relatively regular, and the radiation characteristics are stable, showing good consistency at different angles.

[0122] Please see Figure 20 , Figure 20 This is the radiation pattern of the antenna of the present invention at a frequency of 3.6 GHz with Phi=0. The main lobe is prominent and concentrated, with good energy focusing effect, which is beneficial for directional communication; the sidelobe level is low, with little interference to other directions and high signal purity; the overall shape of the radiation pattern is regular, the radiation characteristics are stable, and the consistency at different angles is good, which can provide stable and reliable signal coverage for communication.

[0123] Please see Figure 21 , Figure 21 The image shows the radiation pattern of the antenna of this invention at a frequency of 4.8 GHz with Phi=90. The main lobe is relatively obvious, and the energy concentration is high, which is conducive to directional signal transmission. The side lobe level is relatively low, which can effectively reduce interference to other directions and ensure signal quality. The overall pattern is regular, the radiation characteristics are stable, and it has good consistency at different angles.

[0124] Please see Figure 22 , Figure 22 The image shows the radiation pattern of the antenna of this invention at a frequency of 4.8 GHz with Phi=0. The antenna in the image has good directivity, with a narrow and strong main lobe that can concentrate energy radiation; low sidelobe level, which can reduce interference; good front-to-back ratio, which avoids energy leakage to the back; symmetrical and stable horizontal radiation characteristics, and excellent overall performance.

[0125] Therefore, the antenna in this embodiment has the advantages of wide operating frequency band, high average gain, high aperture efficiency, and high isolation.

[0126] Regarding operating frequency bands, this embodiment, through the design of a metasurface layer, effectively integrates and utilizes multiple 5G-NR frequency band resources, achieving an operating bandwidth of 40.96%, enabling stable and efficient signal transmission. In complex and ever-changing communication environments, it ensures seamless network connectivity for users, greatly improving the reliability and versatility of communication and meeting the diverse communication application scenarios required in the 5G era.

[0127] Regarding average gain and aperture efficiency, leveraging the electromagnetic properties of metasurfaces, the antenna in this embodiment can efficiently focus and enhance signals, significantly improving antenna gain to achieve an average gain of 13.76 dBi. At the same transmit power, the signal can propagate over a longer distance while maintaining stronger intensity, effectively overcoming the signal attenuation problem of traditional antennas. Simultaneously, it achieves higher aperture efficiency (74.33%) within a smaller footprint. This means that in limited space, the antenna aperture can be utilized more effectively for radiating and receiving signals, reducing energy waste and scattering, further enhancing the overall performance of the antenna and providing a strong guarantee for efficient communication transmission.

[0128] Regarding isolation, in the complex operating environment of multi-antenna systems, this invention ensures high isolation between antennas, exceeding 20.78 dB, through a clever cross-array design. Even when multiple antennas operate simultaneously and signal transmission is frequent, the signals from different antennas maintain a high degree of independence, effectively avoiding mutual interference and greatly improving the capacity and reliability of the communication system.

[0129] In summary, the antenna in this embodiment achieves a wide operating frequency band by setting a metasurface layer in the central unit, integrating and utilizing 5G-NR frequency band resources, ensuring seamless network connectivity, and improving communication reliability and versatility. It leverages the electromagnetic properties of the metasurface to achieve high antenna gain and high aperture efficiency, focusing and enhancing signals, allowing signals to propagate further and with greater intensity at the same transmit power. Simultaneously, it achieves high aperture efficiency with a small area, reducing energy waste and scattering. The use of a cross-array design with diagonally distributed low-frequency auxiliary units and diagonally distributed high-frequency auxiliary units ensures high isolation, enabling independent signal operation when multiple antennas are in operation, avoiding interference, and improving system capacity and reliability.

[0130] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A broadband high-gain 5G base station antenna based on metasurface, characterized in that, include: The system comprises a floor (1), a first low-frequency auxiliary unit (2), a second low-frequency auxiliary unit (3), a first high-frequency auxiliary unit (4), a second high-frequency auxiliary unit (5), a central unit (6), and a power supply network (7), wherein, The first low-frequency auxiliary unit (2), the second low-frequency auxiliary unit (3), the first high-frequency auxiliary unit (4) and the second high-frequency auxiliary unit (5) are arranged in an array on the first surface of the system floor (1) and around the central unit (6). The first low-frequency auxiliary unit (2) and the second low-frequency auxiliary unit (3) are arranged diagonally, and the first high-frequency auxiliary unit (4) and the second high-frequency auxiliary unit (5) are arranged diagonally. The central unit (6) is located in the center of the system floor (1) and includes a metasurface layer (61) and a dual polarization unit. The dual polarization unit is located on the first surface of the system floor (1) and the metasurface layer (61) is fixed on the dual polarization unit. The dual-polarization unit, the first low-frequency auxiliary unit (2), the second low-frequency auxiliary unit (3), the first high-frequency auxiliary unit (4), and the second high-frequency auxiliary unit (5) all include a reflective layer and a feed balun disposed between the reflective layer and the system floor (1); The first reflective layer (62) in the dual polarization unit includes a second dielectric substrate (621) and four spindle-shaped patches (622), which are centrally symmetrically disposed on the surface of the second dielectric substrate (621) away from the system floor (1). The second reflective layer (21) in the first low-frequency auxiliary unit (2) and the second low-frequency auxiliary unit (3) includes a fifth dielectric substrate (211), a hollow rhombus patch (212), and four nested willow leaf patches (213); the hollow rhombus patch (212) and the four nested willow leaf patches (213) are disposed on the surface of the fifth dielectric substrate (211) away from the system floor (1); the four nested willow leaf patches (213) are centrally symmetrically arranged and located inside the hollow rhombus patch (212); The third reflective layer (41) in the first high-frequency auxiliary unit (4) and the second high-frequency auxiliary unit (5) includes an eighth dielectric substrate (411) and four windmill blade-shaped patches (412), which are centrally symmetrically arranged on the surface of the eighth dielectric substrate (411). The frequency bands of the first low-frequency auxiliary unit (2) and the second low-frequency auxiliary unit (3) are 3-4 GHz, and the frequency bands of the first high-frequency auxiliary unit (4) and the second high-frequency auxiliary unit (5) are 4-5 GHz. After forming the array, the distance between the centers of two adjacent auxiliary units is 0.6 times the wavelength, the distance between the center of each auxiliary unit and the center of the central unit (6) is 0.75 times the wavelength, and each auxiliary unit and the central unit (6) generate electromagnetic coupling, and the low-frequency auxiliary unit and the high-frequency auxiliary unit are coupled to each other. The coupling effect is used to optimize the frequency band of all units to 3.3-5 GHz. The antenna can simultaneously cover the N77, N78 and N79 frequency bands of 5G-NR. The power supply network (7) is disposed on the second surface of the system floor (1) and is connected to the first low-frequency auxiliary unit (2), the second low-frequency auxiliary unit (3), the first high-frequency auxiliary unit (4), the second high-frequency auxiliary unit (5) and the central unit (6) respectively via coaxial lines; the power supply network (7) includes a first sub-network (71) and a second sub-network (72), the first sub-network (71) is used to connect microstrip feed lines with a first polarization angle, and the second sub-network (72) is used to connect microstrip feed lines with a second polarization angle. Both the first sub-network (71) and the second sub-network (72) include two Wilkinson power dividers and two T-type power dividers.

2. The broadband high-gain 5G base station antenna based on metasurface according to claim 1, characterized in that, The metasurface layer (61) includes a first dielectric substrate (611) and a plurality of cross-shaped patches (612), wherein, The plurality of cross-shaped patches (612) are distributed in a cross array on the surface of the first dielectric substrate (611) away from the system floor (1); Each cross-shaped patch (612) is formed by a solid cross-shaped patch (6121) and four hollow symmetrical M-shaped patches (6122) connected to the four ends of the solid cross-shaped patch (6121). Each hollow symmetrical M-shaped patch (6122) has two mirror-symmetrical M-shaped units, and each M-shaped unit is formed by bending microstrip lines.

3. The broadband high-gain 5G base station antenna based on metasurface according to claim 2, characterized in that, Each branch of the solid cross-shaped patch (6121) is equivalent to an inductor; In each M-shaped unit, each sub-microstrip line extending along the branch of the solid cross-shaped patch (6121) is equivalent to an inductor, and the blank portion between two microstrip lines is equivalent to a capacitor; the blank portion between two M-shaped units is equivalent to a capacitor. The equivalent circuit of the hollowed-out symmetrical M-shaped patch (6122) is a capacitor and an inductor connected in series.

4. The broadband high-gain 5G base station antenna based on metasurface according to claim 1, characterized in that, The dual-polarization unit includes a first reflective layer (62) and a first feed balun (63), wherein, The metasurface layer (61) is fixed to one side of the first reflective layer (62) by a plurality of studs (64); The first power supply balun (63) is disposed on the other side of the first reflective layer (62) and fixed to the first surface of the system floor (1) by means of a tab; The first feed balun (63) is connected to the feed network (7) via a coaxial line.

5. The broadband high-gain 5G base station antenna based on metasurface according to claim 1, characterized in that, Each spindle-shaped patch (622) includes a first straight line segment (6221) and two first smooth curve segments (6222), the two first smooth curve segments (6222) extending from the two ends of the first straight line segment (6221) until they intersect to form a closed axisymmetric figure; the first straight line segments (6221) of the four spindle-shaped patches (622) are close to each other and opposite each other.

6. The broadband high-gain 5G base station antenna based on metasurface according to claim 4, characterized in that, The first feed balun (63) includes a first center feed assembly (631) and a second center feed assembly (632) that are spatially perpendicularly intersecting, wherein, The first central power supply assembly (631) includes a third dielectric substrate (6311), a first microstrip power supply line (6312), a first parasitic patch (6313), and a second parasitic patch (6314); the third dielectric substrate (6311) is fixed on the system floor (1) by inserts, the first microstrip power supply line (6312) is disposed on the first surface of the third dielectric substrate (6311) and connected to the power supply network (7) by a coaxial line, and the first parasitic patch (6313) and the second parasitic patch (6314) are symmetrically distributed on the second surface of the third dielectric substrate (6311); The second center power supply assembly (632) includes a fourth dielectric substrate (6321), a second microstrip power supply line (6322), a third parasitic patch (6323), and a fourth parasitic patch (6324); the fourth dielectric substrate (6321) is fixed to the system floor (1) by inserts, the second microstrip power supply line (6322) is disposed on the first surface of the fourth dielectric substrate (6321) and connected to the power supply network (7) by a coaxial line, and the third parasitic patch (6323) and the fourth parasitic patch (6324) are symmetrically distributed on the second surface of the fourth dielectric substrate (6321); The first microstrip feed line (6312) and the second microstrip feed line (6322) form an electromagnetic coupling structure in the intersection area, constituting the power supply network of the dual-polarization unit.

7. The broadband high-gain 5G base station antenna based on metasurface according to claim 1, characterized in that, The first low-frequency auxiliary unit (2) and the second low-frequency auxiliary unit (3) have the same structure, both including a second reflective layer (21) and a second feed balun (22) fixed between the second reflective layer (21) and the system floor (1), wherein, Each nested willow leaf-shaped patch (213) in the second reflective layer (21) includes a nested inner ring (2131) and an outer ring (2132), and the inner ring (2131) and the outer ring (2132) have the same shape; The second feed balun (22) includes a first low-frequency feed component (221) and a second low-frequency feed component (222) that are spatially vertically intersected; The first low-frequency power supply assembly (221) includes a sixth dielectric substrate (2211), a third microstrip power supply line (2212), a fifth parasitic patch (2213), and a sixth parasitic patch (2214); the sixth dielectric substrate (2211) is fixed on the system floor (1) by inserts, the third microstrip power supply line (2212) is disposed on the first surface of the sixth dielectric substrate (2211) and connected to the power supply network (7) by a coaxial line, and the fifth parasitic patch (2213) and the sixth parasitic patch (2214) are symmetrically distributed on the second surface of the sixth dielectric substrate (2211); The second low-frequency power supply assembly (222) includes a seventh dielectric substrate (2221), a fourth microstrip power supply line (2222), a seventh parasitic patch (2223), and an eighth parasitic patch (2224); the seventh dielectric substrate (2221) is fixed on the system floor (1) by inserts, the fourth microstrip power supply line (2222) is disposed on the first surface of the seventh dielectric substrate (2221) and connected to the power supply network (7) by a coaxial line, and the seventh parasitic patch (2223) and the eighth parasitic patch (2224) are symmetrically distributed on the second surface of the seventh dielectric substrate (2221); The third microstrip feed line (2212) and the fourth microstrip feed line (2222) form an electromagnetic coupling structure in the intersection area, constituting the radiation network of the low-frequency auxiliary unit.

8. The broadband high-gain 5G base station antenna based on metasurface according to claim 1, characterized in that, The first high-frequency auxiliary unit (4) and the second high-frequency auxiliary unit (5) have the same structure, both including a third reflective layer (41) and a third feed balun (42) fixedly disposed between the third reflective layer (41) and the system floor (1), wherein, The third feed balun (42) includes a first high-frequency feed assembly (421) and a second high-frequency feed assembly (422) that are spatially vertically intersected; The first high-frequency power supply assembly (421) includes a ninth dielectric substrate (4211), a fifth microstrip power supply line (4212), a ninth parasitic patch (4213), and a tenth parasitic patch (4214); the ninth dielectric substrate (4211) is fixed on the system floor (1) by inserts, the fifth microstrip power supply line (4212) is disposed on the first surface of the ninth dielectric substrate (4211) and connected to the power supply network (7) by a coaxial line, and the ninth parasitic patch (4213) and the tenth parasitic patch (4214) are symmetrically distributed on the second surface of the ninth dielectric substrate (4211); The second high-frequency power supply assembly (422) includes a tenth dielectric substrate (4221), a sixth microstrip power supply line (4222), an eleventh parasitic patch (4223), and a twelfth parasitic patch (4224); the tenth dielectric substrate (4221) is fixed on the system floor (1) by inserts, the sixth microstrip power supply line (4222) is disposed on the first surface of the tenth dielectric substrate (4221) and connected to the power supply network (7) by a coaxial line, and the eleventh parasitic patch (4223) and the twelfth parasitic patch (4224) are symmetrically distributed on the second surface of the tenth dielectric substrate (4221); The fifth microstrip feed line (4212) and the sixth microstrip feed line (4222) form an electromagnetic coupling structure in the intersection area, constituting the power supply network of the high-frequency auxiliary unit.

9. The broadband high-gain 5G base station antenna based on metasurface according to claim 1, characterized in that, The power supply network (7) includes a first sub-network (71) and a second sub-network (72), wherein, The first sub-network (71) is used to connect a microstrip feeder with a first polarization angle, including a first Wilkinson power divider (WPD1), a second Wilkinson power divider (WPD2), a first T-type power divider (T1), and a second T-type power divider (T2); the input terminal of the first Wilkinson power divider (WPD1) serves as the first external port (P1) of the feeder network (7), the first output terminal is connected to the input terminal of the second Wilkinson power divider (WPD2), and the second output terminal is connected to the input terminal of the first T-type power divider (T1); the first The first output terminal of the T-type power divider (T1) serves as the first output port (H1) of the power supply network (7), and the second output terminal is connected to the input terminal of the second T-type power divider (T2); the first and second output terminals of the second T-type power divider (T2) serve as the second output port (H2) and the third output port (H3) of the power supply network (7), respectively; the first and second output terminals of the second Wilkinson power divider (WPD2) serve as the fourth output port (H4) and the fifth output port (H5) of the power supply network (7), respectively. The second sub-network (72) is used to connect microstrip feed lines with a second polarization angle, including a third Wilkinson power divider (WPD3), a fourth Wilkinson power divider (WPD4), a third T-type power divider (T3), and a fourth T-type power divider (T4); the input terminal of the third Wilkinson power divider (WPD3) serves as the second external port (P2) of the feed network (7), the first output terminal is connected to the input terminal of the fourth Wilkinson power divider (WPD4), and the second output terminal is connected to the input terminal of the third T-type power divider (T3); the third T... The first output terminal of the T-type power divider (T3) serves as the sixth output port (H6) of the power supply network (7), and the second output terminal is connected to the input terminal of the fourth T-type power divider (T4); the first and second output terminals of the fourth T-type power divider (T4) serve as the seventh output port (H7) and the eighth output port (H8) of the power supply network (7), respectively; the first and second output terminals of the fourth Wilkinson power divider (WPD4) serve as the ninth output port (H9) and the tenth output port (H10) of the power supply network (7), respectively. The central unit (6) is connected to the first output port (H1) and the sixth output port (H6) via two coaxial lines respectively; the first low-frequency auxiliary unit (2) is connected to the second output port (H2) and the seventh output port (H7) via two coaxial lines respectively; the second low-frequency auxiliary unit (3) is connected to the third output port (H3) and the eighth output port (H8) via two coaxial lines respectively; the first high-frequency auxiliary unit (4) is connected to the fourth output port (H4) and the ninth output port (H9) via two coaxial lines respectively; and the second high-frequency auxiliary unit (5) is connected to the fifth output port (H5) and the tenth output port (H10) via two coaxial lines respectively.

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