A rectangular beam lens antenna

Abstract

The present application relates to the technical field of rectangular beam antenna, and particularly relates to a rectangular beam lens antenna. The lens antenna comprises a feed source and a lens; the feed source comprises at least one radiation unit; the lens is a sandwich type multilayer structure, comprising: a middle dielectric layer and super surface layers symmetrically arranged on both sides of the middle dielectric layer; the equivalent dielectric constant of the super surface layer is smaller than the dielectric constant of the middle dielectric layer, and the farther the distance from the middle dielectric layer, the smaller the equivalent dielectric constant of the super surface layer; gaps are arranged between adjacent super surface layers, and the layer spacing is maintained through a support structure. The rectangular beam lens antenna of the present application replaces the traditional complex array or multilayer gradient refractive index lens through the composite structure of the dielectric substrate and the super surface, so as to realize the rectangular beam with steep drop characteristics through the simplified process design, and at the same time, the miniaturization of the antenna volume is realized.

Description

Technical Field

[0001] This invention relates to the field of rectangular beam antenna technology, and more particularly to a rectangular beam lens antenna. Background Technology

[0002] With the large-scale deployment of mobile communication networks in high-density hotspot areas such as stadiums, convention centers, and transportation hubs, traditional 65° directional base station antennas have revealed problems such as blurred coverage boundaries, severe interference from neighboring cells, and low frequency reuse efficiency in these scenarios. To solve these problems, the industry typically uses rectangular beamforming antennas (also known as square beamforming antennas). By making the main beam present an approximately rectangular cross-sectional shape in the horizontal and / or vertical planes, and by causing the lobes outside the half-power angle to drop rapidly, the venue is divided into multiple rectangular sectors. This results in clear coverage boundaries, controllable overlapping areas, reduced interference from neighboring cells on the same frequency, and improved network capacity.

[0003] To achieve rectangular beams, the two existing typical technical solutions are as follows: The first type of solution uses an array antenna to achieve rectangular beamforming. For example, patent document CN109273828A discloses a 5×5 array scheme. However, this scheme has a complex feeding network, and the radiating elements in the array use the principle of reverse cancellation, which has a significant impact on the antenna's radiation efficiency. For array antenna schemes, existing implementations usually rely on large-scale radiating element arrays and complex multi-stage feeding networks, resulting in a high overall antenna profile, difficulty in controlling assembly tolerances, and limited antenna radiation efficiency due to long feeding paths and high losses, leading to high material and processing costs.

[0004] The second approach involves using lens antennas to achieve rectangular beams. Spherical or cylindrical lenses can generate narrow beams through appropriate feed arrangements, and are also used in stadium settings. However, due to the narrow beam of a single lens, a multi-beam lens antenna solution is usually required to cover the required sector of the stadium, resulting in a large number of components and high system costs. Furthermore, the high profile of spherical / cylindrical lenses contradicts the stadium's requirement for low-profile antennas and concealed installation. For multi-beam lens antenna solutions, existing lenses mostly use spherical or cylindrical structures. Their internal structure requires complex gradient refractive index design (i.e., the dielectric constant gradually changes from the inner to the outer layer) to achieve beam focusing, which is difficult to manufacture. Additionally, the spherical or cylindrical geometry results in a large antenna size and windward area, making construction and installation extremely inconvenient in stadiums with limited installation space or strict requirements for load-bearing and wind resistance.

[0005] For the reasons mentioned above, the present invention provides a rectangular beam antenna to solve the problems of complex array feeding / low efficiency, complex lens structure / large size / high cost, and high manufacturing difficulty in rectangular beam implementation when existing rectangular beam antennas are used to achieve coverage in special scenarios such as large venues and transportation hubs. Summary of the Invention

[0006] The rectangular beam lens antenna provided by the present invention is used to solve at least one of the above-mentioned technical problems.

[0007] A rectangular beam lens antenna includes: a feed source and a lens; The feed source includes at least one radiating element; The lens includes: an intermediate dielectric layer and metasurface layers symmetrically disposed on both sides of the intermediate dielectric layer; The metasurface layer includes multiple metasurface units arranged according to a predetermined pattern, and at least one metasurface layer is provided on one side of the intermediate dielectric layer. The equivalent dielectric constant of each of the metasurface layers is less than the dielectric constant of the intermediate dielectric layer.

[0008] Furthermore, the dielectric constant of the intermediate dielectric layer is 1.5 to 2.5.

[0009] Furthermore, the metasurface unit is a patterned metal patch; when multiple metasurface layers are provided on one side of the intermediate dielectric layer, a layer spacing is provided between adjacent metasurface layers, and the layer spacing is maintained by a support structure.

[0010] Furthermore, the metasurface layer farther away from the intermediate dielectric layer has a smaller equivalent dielectric constant; the geometric dimensions of the metal patch in the metasurface layer closer to the intermediate dielectric layer are larger than the geometric dimensions of the metal patch in the metasurface layer farther away from the intermediate dielectric layer.

[0011] Furthermore, it also includes a metasurface layer closest to the intermediate dielectric layer, which is formed by attaching a metal patch to the surface of the intermediate dielectric layer.

[0012] Furthermore, the support structure includes a plurality of spaced plastic support members, the metasurface layer also includes a dielectric film, and the metal patch is disposed on the dielectric film and is integrally supported and mounted on both sides of the intermediate dielectric layer through the support structure.

[0013] Furthermore, the support structure is a dielectric support layer, and the dielectric constant of the dielectric support layer is not greater than 1.5.

[0014] Furthermore, the metal patch includes a metal foil, which is attached to the surface of the intermediate dielectric layer or the surface of the dielectric support layer by means of adhesion.

[0015] Furthermore, when the number of radiating units is one, the top view profile of the lens is a square or a circle; when the number of radiating units is greater than or equal to two, the top view profile of the lens is an N-sided polygon, where N is a positive integer greater than 3.

[0016] A method for forming a rectangular beam of a rectangular beam lens antenna, employing the rectangular beam lens antenna; the method for forming the rectangular beam includes: Step S1: Determine the number of feed sources, the shape and dielectric constant of the intermediate dielectric layer, the number of metasurface layers, the distance between metasurface layers, and the equivalent dielectric constant of each metasurface layer; Step S2: Select the pattern of the metasurface unit of the metasurface layer, simulate each metasurface layer, and determine the specific geometric dimensions and arrangement rules of the metasurface unit of each metasurface layer; Step S3: Construct the rectangular beam lens antenna based on the simulation results; the feed source is used to radiate electromagnetic waves, and the electromagnetic waves are modulated by the lens to form a rectangular beam with steep drop characteristics in the far field.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. The rectangular beam lens antenna of this invention utilizes a composite structure consisting of a dielectric substrate and a metasurface layer. It achieves a high-performance rectangular beam with only a single-layer dielectric substrate and a double-sided metasurface. Compared to traditional 5×5 array antennas, it eliminates the complex power divider network and numerous radiating elements, significantly improving radiation efficiency. Compared to traditional spherical lenses, it greatly reduces the profile height, facilitating concealed installation within venues and significantly lowering manufacturing costs. This rectangular beam lens antenna can replace traditional complex arrays or multi-layered gradient refractive index lenses, achieving a rectangular beam with steep-drop characteristics through simplified process design, while simultaneously miniaturizing the antenna size.

[0018] 2. The rectangular beam lens antenna of the present invention provides a simplified rectangular beamforming scheme. By optimizing the lens body structure through structural and parameter design, the longitudinal dimension and overall volume of the antenna are effectively reduced while ensuring the steep descent characteristics of the rectangular beam. This reduces the difficulty of manufacturing and the complexity of construction and installation, thereby overcoming the defects of existing technologies such as complex structure, low efficiency, large size, and high cost. Compared with the existing array and lens approaches for achieving rectangular beams, this invention can simultaneously meet the requirements of steep descent characteristics, high efficiency, low profile, miniaturization, and low cost. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the rectangular beam lens antenna in Embodiment 1 of the present invention; Figure 2 This is a side view schematic diagram of the rectangular beam lens antenna in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the metasurface layer structure of the rectangular beam lens antenna in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the lens structure and its interaction with the intermediate dielectric layer in the rectangular beam lens antenna of Embodiment 1 of the present invention. Figure 5 This is one of the schematic diagrams of the metasurface unit of the metasurface layer of the rectangular beam lens antenna in Embodiment 1 of the present invention; Figure 6 This is a second schematic diagram of the metasurface unit pattern of the metasurface layer of the rectangular beam lens antenna in Embodiment 1 of the present invention; Figure 7 This is the third schematic diagram of the metasurface unit pattern of the metasurface layer of the rectangular beam lens antenna in Embodiment 1 of the present invention; Figure 8 A schematic diagram illustrating the method for determining the interlayer spacing and equivalent dielectric constant of metasurface layers; Figure 9 This is a horizontal plane orientation pattern of the rectangular beam formed by the rectangular beamforming method of Embodiment 2 of the present invention; Figure 10 This is a vertical plane orientation diagram of the rectangular beam formed by the rectangular beamforming method of Embodiment 2 of the present invention.

[0021] Figure label: 10-Feed source; 20-Lens; 21-Intermediate dielectric layer; 22-Metasurface layer; 221-First metasurface layer; 222-Second metasurface layer; 223-Third metasurface layer; 2201-Transverse metal sheet; 2202-Extended metal sheet; 2203-T-shaped metal sheet; 2204-Chamfered metal sheet. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0023] Example 1 One specific embodiment of the present invention provides a rectangular beam lens antenna, such as... Figures 1-4 As shown, the system includes a feed source 10 and a lens 20. The feed source 10 contains at least one radiating element. The lens 20 has a "sandwich" multilayer structure, including an intermediate dielectric layer 21 and metasurface layers 22 symmetrically arranged on both sides of the intermediate dielectric layer. The metasurface layer 22 includes periodically arranged metasurface units, and at least one layer of the metasurface layer 22 is disposed on one side of the intermediate dielectric layer 21. The equivalent dielectric constant of the metasurface layer 22 is smaller than that of the intermediate dielectric layer 21, and the equivalent dielectric constant of the metasurface layer 22 is smaller the farther away from the intermediate dielectric layer 21. There is a gap between adjacent metasurface layers 22, and the interlayer spacing is maintained by a support structure.

[0024] In this embodiment, the feed source 10 is used to transmit or receive electromagnetic wave signals; the lens 20 is disposed on the electromagnetic wave radiation path of the feed source 10 and is used to perform wavefront modulation on the spherical wave radiated by the feed source 10 so that it forms a rectangular far-field radiation pattern on a specific plane (such as a horizontal plane or a vertical plane).

[0025] In one specific embodiment of the present invention, the dielectric constant of the intermediate dielectric layer is between 1.5 and 2.5.

[0026] In this embodiment, as Figure 2As shown, the lens 20 adopts a "sandwich" multi-layer planar structure, specifically including an intermediate dielectric layer 21 and a pair of metasurface layers 22 disposed on both sides of the intermediate dielectric layer 21. In this embodiment, the core design point of the rectangular beam lens antenna is the positional relationship and parameter design of the intermediate dielectric layer 21 and the metasurface layers 22; specifically, the intermediate dielectric layer 21 is located at the center of the lens 20, serving as mechanical support and preliminary impedance matching. The intermediate dielectric layer 21 is made of a low-loss dielectric substrate with a dielectric constant between 1.5 and 2.5. This dielectric constant range ensures sufficient mechanical strength while reducing electromagnetic wave reflection loss inside the lens. The intermediate dielectric layer 21 not only serves as a carrier for electromagnetic wave propagation but also as a rigid support for the two metasurface layers 22, simplifying the complex support structure of traditional lenses.

[0027] Furthermore, metasurface layers 22 are distributed in pairs on both sides of the intermediate dielectric layer 21 (i.e., the inner side facing the feed and the outer side facing away from the feed), and each side contains at least one metasurface layer; artificial electromagnetic metasurfaces are used to realize the focusing function of the lens.

[0028] In this embodiment, the effective dielectric constant distribution principle of the metasurface layer 22 is as follows: the magnitude of the dielectric constant varies with the distance of the metasurface layer 22 from the intermediate dielectric layer 21. Specifically, the metasurface layer 22 farther from the intermediate dielectric layer 21 has a smaller effective dielectric constant. This distribution of the effective dielectric constant, which decreases from the center to the edge of the lens 20, simulates the refractive index distribution of a traditional Luneburg lens, enabling the conversion of spherical waves into plane waves.

[0029] In one specific embodiment of the present invention, the metasurface unit is a patterned metal patch.

[0030] Furthermore, the metasurface layer 22 is composed of periodically arranged metasurface units. The metasurface units are metal patches used to form rectangular beams, and the patterns of the metasurface units can adopt Jerusalem cross, cross shape and / or square ring structure.

[0031] Specifically, such as Figure 5 As shown, when the shape of the metal patch is a Jerusalem cross, it includes a central cross-shaped metal piece, a horizontal metal piece 2201, and an extended metal piece 2202; the horizontal metal piece 2201 is arranged perpendicular to the cross-shaped metal piece and its end is connected to the extended metal piece 2202; preferably, the angle between the extended metal piece 2202 and the horizontal metal piece 2201 is set to 30° to 45°.

[0032] Specifically, such as Figure 6 As shown, the metal patch is formed by four T-shaped metal pieces 2203 arranged symmetrically at the center.

[0033] Specifically, such as Figure 7As shown, the pattern of the metal patch can be changed by reducing the size of the cross-shaped metal patch and opening a metal chamfer 2204 at the end of the patch.

[0034] In this embodiment, when the metasurface unit has multiple layers, metal patches with different patterns are used as metasurface units to facilitate the differentiation of metasurface units between different layers and to ensure the accuracy of lens structure installation.

[0035] In this embodiment, the metasurface units of the multilayer metasurface layer 22 adopt a size gradient design: the metasurface units of the metasurface layer 22 closer to the intermediate dielectric layer 21 have larger geometric dimensions to provide a higher equivalent dielectric constant; the metasurface units of the metasurface layer 22 further away from the intermediate dielectric layer 21 (i.e. located on the outermost side) have smaller geometric dimensions to provide a lower equivalent dielectric constant.

[0036] Furthermore, the processing technology of the metasurface unit is as follows: the metal pattern of the metasurface layer 22 can be printed on the PCB and supported and fixedly connected with the intermediate dielectric layer through the support structure; or a metal sheet (such as copper foil) can be formed by etching or stamping and directly bonded to the surface of the intermediate dielectric layer 21 to form the innermost metasurface layer 22.

[0037] In one specific embodiment of the present invention, such as Figure 1 , Figure 3 As shown, when there is only one radiating element, the top view profile of the lens 20 is preferably square or circular. A single feed combined with a square lens is beneficial for obtaining symmetrical rectangular beams in both the E-plane and H-plane. When there are two or more radiating elements (e.g., forming a linear array or area array), the top view profile of the lens 20 can be adjusted to a rectangle or other polygon, depending on the number of radiating elements, to meet the requirements of multi-beam combining or beam broadening in a specific direction.

[0038] Specifically, when the number of radiation units is one, the top view profile of the lens is either angular or circular; and the radiation unit is positioned coaxially with the central axis of the lens.

[0039] Specifically, when the number of radiating elements is greater than or equal to two, the multiple radiating elements are arranged in a linear array or a surface array; when the radiating elements are arranged in a linear array, the top view profile of the lens is rectangular, and the aspect ratio of the rectangle is determined according to the number of radiating elements; when the radiating elements are arranged in a surface array, the top view profile of the lens 20 is set to be a polygon, preferably a regular polygon, and the number of sides of the polygon is determined according to the arrangement of the radiating elements.

[0040] The rectangular beam lens antenna of this invention features a matching rule for the feed and lens profiles: When there is one radiating element, the lens's top-view profile is square / circular, suitable for single-beam rectangular coverage; when there are two or more radiating elements, the lens's top-view profile is rectangular, suitable for multi-beam / wide-sector rectangular coverage. Compared to traditional lenses, which often have fixed profiles and require different lens specifications for single / multi-feed scenarios, resulting in poor versatility, this invention, through a single lens architecture design, can flexibly adapt to the different sector division requirements of a venue. It eliminates the need for redesigning the mold, enabling the electromagnetic waves radiated from the feed to form a rectangular beam with steep descent characteristics in the far field after being modulated by the lens.

[0041] In one specific embodiment of the present invention, the metal patch is adhered to the surface of the intermediate dielectric layer to form a metasurface layer closest to the intermediate dielectric layer. Alternatively, it can be spaced apart by a support structure. Further, adjacent metasurface layers 22 are spaced apart by a support structure.

[0042] like Figure 4 As shown, when a single-sided metasurface layer 22 has three layers, namely a first metasurface layer 221, a second metasurface layer 222, and a third metasurface layer 223, adjacent metasurface layers 22 are spaced apart by a support structure. That is to say, in this embodiment, interlayer supports and air gaps are provided between the multiple metasurface layers 22: adjacent metasurface layers are not completely tightly fitted, but are spaced apart according to actual electromagnetic performance requirements.

[0043] In this embodiment, one method of supporting the metasurface layer is discrete support: discrete plastic support columns or multiple support walls are used as the support structure to maintain the interlayer gap of the metasurface layer 22. Further, the support structure consists of discretely arranged plastic support members, and the metal patches are printed on the dielectric film using a printed circuit board process. The dielectric film and the metal patches on its surface form a whole, which is supported and installed on both sides of the intermediate dielectric layer by the support structure. To reduce disturbance to the electromagnetic wave phase distribution, the volume of the plastic support members should be as small as possible, and preferably made of a low dielectric constant material (such as nylon or PP), and should avoid the central region of the antenna aperture surface.

[0044] In this embodiment, one of the second methods of supporting the metasurface layer is continuous support: a whole layer of low dielectric constant dielectric material is used as the dielectric support layer to fill the gaps. Foam material with extremely low dielectric constant or an air layer is preferred. Using foam material ensures structural stability while maintaining a low equivalent dielectric constant, reducing negative impacts on the radiation pattern. Specifically, when the support structure is a dielectric support layer, the dielectric constant of the dielectric support layer is no greater than 1.5; the metal patch is attached to the surface of the intermediate dielectric layer or the dielectric support layer using a metal foil bonding method.

[0045] The working principle of the rectangular beam lens antenna of the present invention: When the electromagnetic wave emitted by the feed 10 passes through the lens 20, the propagation speed of the electromagnetic wave varies in different regions due to the gradient distribution of the equivalent dielectric constant of the metasurface layer 22. The wave speed is slower near the middle dielectric layer 21 and faster at the edge. By simulating the design of the size and arrangement of the metasurface units of each metasurface layer 22, rays from different paths emitted from the feed reach the exit surface with the same phase, thus forming in-phase plane waves. The rectangular beam lens antenna of this invention has a simple structure and can achieve equivalent dielectric constant matching by adjusting the number of layers, spacing, and pattern arrangement of the metasurface layers 22. Compared with traditional array antennas or single multilayer metasurface lens antennas, it can significantly reduce the size and cost of the lens antenna.

[0046] In this embodiment, an integrated low-profile planar lens structure is formed by an intermediate dielectric layer 21 with the same dielectric constant and paired metasurface layers 22 on both sides, with the intermediate dielectric layer 21 also serving as a support for the metasurface layer 22. This eliminates the complex dielectric configuration required by traditional spherical / cylindrical lenses, where the dielectric constant gradually changes from the inside to the outside, and also eliminates the multi-level network + multi-radiative unit architecture of array schemes. It solves the problems of traditional gradient lenses, which require the fabrication of multiple layers of dielectric materials with different formulations or complex doped structures, resulting in high process difficulty; and the array scheme, which has many feeding network layers, high loss, and low radiation efficiency.

[0047] The rectangular beam lens antenna of this invention uses only one homogeneous dielectric substrate with a dielectric constant of 1.5~2.5 as the core layer, with symmetrically attached / printed metasurface layers on both sides (only the metasurface layers are gradient). The intermediate dielectric layer 21 simultaneously undertakes the functions of electromagnetic wave matching transmission and metasurface mechanical support. The overall structure is simplified to a "sandwich" planar configuration, achieving a low profile design, eliminating the need for complex power divider networks, reducing assembly difficulty, and providing radiation efficiency superior to array solutions of the same specifications, while significantly reducing costs.

[0048] Example 2 A specific embodiment of the present invention provides a rectangular beamforming method for a rectangular beam lens antenna, employing the rectangular beam lens antenna described in Embodiment 1; the rectangular beamforming method includes: Step S1: Determine the number of feed sources, the shape and dielectric constant of the intermediate dielectric layer, the number of metasurface layers, the distance between metasurface layers, and the equivalent dielectric constant of each metasurface layer; Step S2: Select the pattern of the metasurface unit of the metasurface layer, simulate each metasurface layer, and determine the specific geometric dimensions and arrangement rules of the metasurface unit of each metasurface layer; Step S3: Construct the rectangular beam lens antenna based on the simulation results; the feed source is used to radiate electromagnetic waves, and the electromagnetic waves are modulated by the lens to form a rectangular beam with steep drop characteristics in the far field.

[0049] In this embodiment, the equivalent dielectric constant from the intermediate dielectric layer 21 to the multilayer metasurface layer 22 decreases sequentially according to the distance from the intermediate dielectric layer 21.

[0050] In step S1, the methods for determining the distance between the multiple metasurface layers 22 and the equivalent dielectric constant of each metasurface layer 22 include: Method 1: Set the multilayer metasurface layers 22 to have equal dielectric constant intervals, and assign equivalent dielectric constant values ​​to the multilayer metasurface layers 22 in a stepped distribution with equal intervals; for example, select values ​​from the dielectric constant intervals of 2, 1.8, 1.6, 1.4, and 1.2; determine the distance between different metasurface layers 22 based on the values ​​of the equivalent dielectric constant, and construct an equivalent lens accordingly, such as... Figure 8 As shown in (a) and (c) in the figure.

[0051] Method 2: A defined spacing is established between the multiple metasurface layers 22; by fixing the distance between the multiple metasurface layers 22, and aiming to achieve a lens effect, the equivalent dielectric constant is determined; for example... Figure 8 As shown in (b) and (d) in the figure.

[0052] It is worth noting that in this embodiment, when using the equal-interval dielectric constant value method, it is not required that the dielectric constant of the intermediate dielectric layer 21 and the equivalent dielectric constant of the multilayer metasurface layer 22 be distributed "equally"; when using the equal-interval value method, it is not required that the thickness of the intermediate dielectric layer 21 and the spacing distance of the multilayer metasurface layer 22 be distributed "equally".

[0053] In step S2, after determining the equivalent dielectric constant of the metasurface layer 22, the metasurface is simulated: the metasurface unit is modeled as an "infinite period array" in the simulation software, the area parameter S is extracted, and then the equivalent impedance Z and equivalent refractive index n of the metasurface layer 22 are calculated by the parameter inversion method. Finally, the equivalent dielectric constant of the metasurface layer 22 is obtained according to the formula ε=n / Z. By matching the equivalent dielectric constant obtained by simulation with the equivalent dielectric constant determined in step S1, the arrangement and geometric parameters of the metasurface unit can be determined in reverse.

[0054] In this embodiment, the gradient rule and implementation method of the equivalent dielectric constant of the metasurface layer 22 are as follows: the farther away from the intermediate dielectric layer 21, the smaller the equivalent dielectric constant. The gradient of different metasurface layers 22 is achieved through the shape and size of the metal patch of the metasurface unit, without changing the dielectric constant of the dielectric material itself. The distribution of the equivalent dielectric constant of the metasurface layer 22 simulates the refractive index distribution of a traditional Luneburg lens, but it is not achieved by adjusting the dielectric material formula. Instead, it is achieved by the gradual change of the geometric size of the metasurface unit: the metasurface unit closer to the intermediate dielectric layer 21 is larger and corresponds to a higher equivalent dielectric constant; the metasurface unit farther away from the intermediate dielectric layer 21 is smaller and corresponds to a lower equivalent dielectric constant.

[0055] In this embodiment, by optimizing the arrangement of the metasurface layer, the beamwidth in the two vertical planes is controlled, ultimately achieving a rectangular beam with steep edges, such as... Figure 9 , Figure 10 As shown.

[0056] Compared with the prior art, the rectangular beam lens antenna in this embodiment has at least one of the following beneficial effects: 1. This invention achieves gradient control simply by adjusting the size of the metasurface unit using conventional PCB printing processes, exhibiting strong process compatibility and high consistency. Combined with a flat panel configuration, it enables the steep descent characteristics of a rectangular beam, adapting to the neighboring-area interference suppression requirements of stadium scenarios. It overcomes the shortcomings of traditional gradient lenses, which require customized dielectric substrates with different formulations for layer-by-layer lamination to achieve gradual changes in dielectric constant, resulting in poor consistency and low yield. Compared to conventional metasurface lenses, it overcomes the need for complex bias feeding or tunable structures to achieve beamforming.

[0057] 2. The gaps between adjacent metasurface layers 22 or between metasurface layer 22 and intermediate dielectric layer 21 in this invention employ two low-impact support schemes: ① discretely arranged small-volume plastic supports are used as the support structure, avoiding the central region of the antenna aperture surface; ② the entire layer is filled with foam / low dielectric constant dielectric material with a dielectric constant ≤1.5 to achieve support. If there is no interlayer support between adjacent metasurface layers 22 or between metasurface layer 22 and intermediate dielectric layer 21, the multilayer structure will be prone to deformation and tolerance control will be difficult. If conventional large-volume supports or high dielectric constant dielectric materials are used, the phase distribution of electromagnetic waves will be interfered with, leading to pattern distortion and deterioration of the rectangular beam's steep drop characteristics. The support scheme of this invention ensures the mechanical stability of the planar lens while minimizing interference with the pattern, guaranteeing the performance consistency of the rectangular beam.

[0058] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, it should be noted that if terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," or "outer" indicate orientation or positional relationships based on the orientation or positional relationships shown in the figures, or the orientation or positional relationships commonly used when the product is in use, they are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, if terms such as "first" or "second" appear in the description of this invention, they are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0059] Furthermore, the use of terms such as "horizontal" and "vertical" in the description of this invention does not imply that the components are required to be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A rectangular beam lens antenna, characterized in that, include: Feed source and lens; The feed source includes at least one radiating element; The lens includes: an intermediate dielectric layer and metasurface layers symmetrically disposed on both sides of the intermediate dielectric layer; The metasurface layer includes multiple metasurface units arranged according to a predetermined pattern, and at least one metasurface layer is provided on one side of the intermediate dielectric layer. The equivalent dielectric constant of each of the metasurface layers is less than the dielectric constant of the intermediate dielectric layer.

2. The rectangular beam lens antenna according to claim 1, characterized in that, The dielectric constant of the intermediate dielectric layer is 1.5 to 2.

5.

3. The rectangular beam lens antenna according to claim 2, characterized in that, The metasurface unit is a patterned metal patch; when multiple metasurface layers are provided on one side of the intermediate dielectric layer, there is a layer spacing between adjacent metasurface layers, and the layer spacing is maintained by a support structure.

4. The rectangular beam lens antenna according to claim 3, characterized in that, The farther the metasurface layer is from the intermediate dielectric layer, the smaller its equivalent dielectric constant; the geometric dimensions of the metal patch in the metasurface layer closer to the intermediate dielectric layer are larger than the geometric dimensions of the metal patch in the metasurface layer farther from the intermediate dielectric layer.

5. The rectangular beam lens antenna according to any one of claims 1-3, characterized in that, It also includes a metasurface layer closest to the intermediate dielectric layer, which is formed by attaching a metal patch to the surface of the intermediate dielectric layer.

6. The rectangular beam lens antenna according to claim 2, characterized in that, The support structure includes multiple spaced plastic support members, the metasurface layer also includes a dielectric film, and the metal patch is disposed on the dielectric film and is integrally supported and installed on both sides of the intermediate dielectric layer through the support structure.

7. The rectangular beam lens antenna according to any one of claims 3-5, characterized in that, The supporting structure is a dielectric support layer, and the dielectric constant of the dielectric support layer is not greater than 1.

5.

8. The rectangular beam lens antenna according to claim 7, characterized in that, The metal patch includes a metal foil, which is attached to the surface of the intermediate dielectric layer or the surface of the dielectric support layer by means of adhesion.

9. The rectangular beam lens antenna according to claim 8, characterized in that, When the number of radiating elements is 1, the top view profile of the lens is a square or a circle; when the number of radiating elements is greater than or equal to 2, the top view profile of the lens is an N-sided polygon, where N is a positive integer greater than 3.

10. A method for forming a rectangular beam of a rectangular beam lens antenna, characterized in that, The rectangular beamforming method employs the rectangular beam lens antenna according to any one of claims 1 to 9, comprising: Step S1: Determine the number of feed sources, the shape and dielectric constant of the intermediate dielectric layer, the number of metasurface layers, the distance between metasurface layers, and the equivalent dielectric constant of each metasurface layer; Step S2: Select the pattern of the metasurface unit of the metasurface layer, simulate each metasurface layer, and determine the specific geometric dimensions and arrangement rules of the metasurface unit of each metasurface layer; Step S3: Construct the rectangular beam lens antenna based on the simulation results; the feed source is used to radiate electromagnetic waves, and the electromagnetic waves are modulated by the lens to form a rectangular beam with steep drop characteristics in the far field.

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