Multi-band array base station antenna

Abstract

The invention provides a multi-band array base station antenna. The multi-band array base station antenna comprises a reflection bottom plate, two columns of low-frequency radiation units, high-frequency radiation units, reflection side plates, isolation strips and a dielectric plate, the high-frequency radiation units are located between two columns of the low-frequency radiation units, the isolating bars are arranged between the adjacent low-frequency radiation units and the high-frequency radiation units and comprise first folded plates, connecting plates and second folded plates which are connected in sequence, and the first folded plates are closest to the low-frequency radiation units and incline towards the low-frequency radiation units; the included angle between the first folded plate and the connecting plate is 60 degrees, and the height of the first folded plate is slightly smaller than 0.5 times of the height of the low-frequency radiation unit. The included angle between the second folded plate and the connecting plate is 90 degrees, and the height of the second folded plate is slightly smaller than 0.5 times of the height of the high-frequency radiation unit. And the two dielectric plates are respectively suspended above the two columns of high-frequency radiation units close to the low-frequency radiation units in parallel. The antenna provided by the invention can effectively solve the problem of beam distortion of a multi-band antenna.

Description

Technical Field

[0001] This application relates to the field of antenna technology, and in particular to a multi-band array base station antenna. Background Technology

[0002] With the development of communication technology, multi-band nested common-aperture antennas have become a mainstream requirement for operators in order to reduce costs and make efficient use of base station space. Multi-band nested common-aperture antennas integrate multi-band arrays into a single aperture, thereby reducing size, lowering costs, and saving base station space.

[0003] However, operators have strict requirements regarding the windward surface, which compresses the layout space of each frequency band array within a multi-band array base station antenna, often placing high-frequency band arrays close to low-frequency band arrays. Due to the mutual coupling between frequency bands, the strong electromagnetic field of the low-frequency band array can interfere with the adjacent high-frequency band array, distorting its electromagnetic field and disrupting beamforming. This leads to distortion problems such as beam shift and increased sidelobes in the high-frequency signal. Beam distortion, in turn, causes bandwidth divergence and energy dispersion in the high-frequency signal, reducing the signal quality in the target area and increasing the risk of interference, ultimately limiting the performance of multi-band array base station antennas.

[0004] It is important to note that the techniques described in this section are not necessarily those previously conceived or adopted. Unless otherwise specified, no technique described in this section should be assumed to be prior art simply because it is included in this section. Similarly, unless otherwise specified, the issues mentioned in this section should not be considered to be recognized in any prior art. Summary of the Invention

[0005] This application provides a multi-band array base station antenna, which aims to solve the technical problem of low-frequency array interference causing severe beam distortion and bandwidth divergence due to high-frequency array interference.

[0006] This application provides a multi-band array base station antenna, the multi-band array base station antenna comprising:

[0007] Reflective base plate, including mounting plate surface;

[0008] Two rows of low-frequency radiating units are disposed on the mounting plate surface;

[0009] Multiple rows of high-frequency radiating units are disposed on the mounting plate, with the multiple rows of high-frequency radiating units located between two rows of low-frequency radiating units;

[0010] Two reflective side plates are connected to the mounting plate surface on one side respectively. The two reflective side plates are located on the side of the two rows of low-frequency radiation units away from the high-frequency radiation units. The angle between the reflective side plates and the mounting plate surface is 90±9°.

[0011] An isolation strip is disposed between adjacent rows of the low-frequency radiation units and the high-frequency radiation units. The isolation strip includes a first folding plate, a connecting plate, and a second folding plate connected in sequence. One side of the connecting plate is connected to the mounting plate. The first folding plate is closer to the low-frequency radiation unit than the second folding plate. The first folding plate is inclined towards the low-frequency radiation unit, and the angle between the first folding plate and the connecting plate is 60±6°. The height of the first folding plate is 0.4 to 0.5 times the height of the low-frequency radiation unit. The angle between the second folding plate and the connecting plate is 90±9°, ​​and the height of the second folding plate is 0.4 to 0.5 times the height of the high-frequency radiation unit.

[0012] Two dielectric plates are respectively suspended above the two rows of high-frequency radiation units near the low-frequency radiation unit. The high-frequency radiation units are located on the side of the high-frequency radiation unit that is away from the mounting plate. The angle between the dielectric plate and the mounting plate is 0 to 1°.

[0013] Optionally, the height of the first folding plate is 12-16 mm, and the height of the second folding plate is 6-9 mm.

[0014] Optionally, in the direction parallel to the mounting plate surface, the shortest distance between the first folding plate and the second folding plate is less than or equal to 10 mm.

[0015] Optionally, the thickness of the isolation strip is 1±0.1mm, and the isolation strip is made of at least one of the following: metal material, metal-dielectric composite material, and microwave absorbing material.

[0016] Optionally, the two ends of the isolation strip are located at the first and last two low-frequency radiation units in the same column, and the two ends of the isolation strip are located at the first and last two high-frequency radiation units in the same column.

[0017] Optionally, the offset distance between the center line of the dielectric substrate and the center line of the high-frequency radiation unit below it is 0 to 1 mm.

[0018] Optionally, the column spacing of any two adjacent columns of the high-frequency radiation units is equal, the column spacing is A, where A is 0.5 to 0.8 times the wavelength of the high-frequency radiation unit, the width of the dielectric substrate is 1A to 2A, the thickness of the dielectric substrate is 1 to 2 mm, and the shortest distance between the dielectric substrate and the mounting plate is A.

[0019] Optionally, A is 50-80 mm.

[0020] Optionally, the dielectric constant of the dielectric substrate is 3 to 5.

[0021] Optionally, the two ends of the dielectric plate are located at the first and last two low-frequency radiation units in the same column, and the two ends of the dielectric plate are located at the first and last two high-frequency radiation units in the same column.

[0022] This application's multi-band array base station antenna optimizes the layout of high-frequency and low-frequency radiating elements by introducing dielectric substrates and isolation strips. It precisely controls the positions and parameters of the dielectric substrates and isolation strips. The dielectric substrate adjusts the electromagnetic field distribution, and the isolation strips block energy crosstalk. This combination effectively suppresses beam distortion and narrowing of the high-frequency signal caused by the low-frequency radiating elements, significantly improving beam efficiency. Specifically, because the height of the multi-band array base station antenna's radome is limited by the size of the low-frequency radiating elements, the horizontal beamwidth of the high-frequency radiating elements is generally narrow, averaging only about 60°, due to the excessive height of the radome. The dielectric substrate acts as a simulated radome, adjusting the horizontal beamwidth of the high-frequency radiating elements to an average of 65°. Due to the overall size limitations of multi-band array base station antennas, the layout space for different frequency band arrays is relatively small. Because of the mutual coupling between frequency bands, especially the severe beam distortion in the high-frequency radiating elements near the low-frequency radiating elements, the beamwidth of the high-frequency radiating elements diverges, with an actual measured value of 65±20°. The specially designed isolation strip can reduce the influence between two frequency bands and decrease beam distortion. The tilted setting of the isolation strip can converge the beamwidth to within 65±10°. Furthermore, the compact structural design of the components of the multi-band array base station antenna in this application significantly reduces the antenna area and material consumption, aligning with the development trend of green and lightweight multi-band array base station antennas.

[0023] It should be understood that the description in this section is not intended to identify key or important features of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0024] The accompanying drawings exemplify embodiments and form part of the specification, working together with the textual description to explain exemplary implementations of the embodiments. The drawings shown are for illustrative purposes only and do not limit the scope of the claims. Throughout the drawings, the same reference numerals refer to similar but not necessarily identical elements.

[0025] Figure 1 A three-dimensional representation of a multi-band array base station antenna according to this application Figure 1 ;

[0026] Figure 2 for Figure 1 The three-dimensional embodiment shown Figure 2 ;

[0027] Figure 3 for Figure 1 A cross-sectional view of the embodiment shown.

[0028] Explanation of reference numerals in the attached figures:

[0029] Figure Labels name Figure Labels name 100 Multi-band array base station antenna 110 Reflective base plate 120 Low-frequency radiation unit 130 High-frequency radiation unit 140 Reflector side plate 150 isolation strip 151 First folding plate 152 Connecting plate 153 Second folding plate 160 medium board 170 isolation structure 180 Support column Detailed Implementation

[0030] To make the inventive objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0032] In the description of the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. The term "multiple" means two or more, unless otherwise explicitly specified. The term "comprising" indicates the presence of the described feature, whole, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or sets thereof. The term "and / or" describes the relationship between related objects, indicating that three relationships may exist. For example, A and / or B may include three cases: A existing alone, A and B existing simultaneously, and B existing alone. The character " / " generally indicates that the related objects before and after are in an "or" relationship.

[0033] Unless otherwise defined, all technical terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art; the terms used in the embodiments of this application are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "comprising" and "having" and any variations thereof in the specification, claims and foregoing description of the drawings of this application are intended to cover non-exclusive inclusion.

[0034] Furthermore, terms such as "exemplary," "for example," and "optional" are used to indicate illustrative purposes. Any technical solution described by the above terms in the embodiments of this application should not be construed as being more preferred or advantageous than other technical solutions. Specifically, these terms are intended to present the relevant technical concepts in terms of specific implementation methods.

[0035] This application provides a multi-band array base station antenna, which includes a reflective base plate, two columns of low-frequency radiating elements, multiple columns of high-frequency radiating elements, two reflective side plates, an isolation strip, and two dielectric substrates. The reflective base plate includes a mounting surface. The two columns of low-frequency radiating elements are disposed on the mounting surface. The multiple columns of high-frequency radiating elements are disposed on the mounting surface, located between the two columns of low-frequency radiating elements. One side of each of the two reflective side plates is connected to the mounting surface, and the two reflective side plates are respectively located on the side of the two columns of low-frequency radiating elements away from the high-frequency radiating elements. The angle between the reflective side plates and the mounting surface is 90±9°. An isolation strip is positioned between adjacent rows of low-frequency and high-frequency radiating units. The isolation strip comprises a first folding plate, a connecting plate, and a second folding plate connected sequentially. One side of the connecting plate connects to the mounting plate. The first folding plate is closer to the low-frequency radiating unit than the second folding plate, and is inclined towards the low-frequency radiating unit. The angle between the first folding plate and the connecting plate is 60±6°, and the height of the first folding plate is 0.4 to 0.5 times the height of the low-frequency radiating unit. The angle between the second folding plate and the connecting plate is 90±9°, ​​and the height of the second folding plate is 0.4 to 0.5 times the height of the high-frequency radiating unit. Two dielectric plates are suspended above the two rows of high-frequency radiating units closest to the low-frequency radiating units. The area above the high-frequency radiating units is the side of the high-frequency radiating unit facing away from the mounting plate. The angle between the dielectric plate and the mounting plate is 0 to 1°.

[0036] This application's multi-band array base station antenna optimizes the layout of high-frequency and low-frequency radiating elements by introducing dielectric substrates and isolation strips. It precisely controls the positions and parameters of the dielectric substrates and isolation strips. The dielectric substrate adjusts the electromagnetic field distribution, and the isolation strips block energy crosstalk. This combination effectively suppresses beam distortion and narrowing of the high-frequency signal caused by the low-frequency radiating elements, significantly improving beam efficiency. Specifically, because the height of the multi-band array base station antenna's radome is limited by the size of the low-frequency radiating elements, the horizontal beamwidth of the high-frequency radiating elements is generally narrow, averaging only about 60°, due to the excessive height of the radome. The dielectric substrate acts as a simulated radome, adjusting the horizontal beamwidth of the high-frequency radiating elements to an average of 65°. Due to the overall size limitations of multi-band array base station antennas, the layout space for different frequency band arrays is relatively small. Because of the mutual coupling between frequency bands, especially the severe beam distortion in the high-frequency radiating elements near the low-frequency radiating elements, the beamwidth of the high-frequency radiating elements diverges, with an actual measured value of 65±20°. The specially designed isolation strip can reduce the influence between two frequency bands and decrease beam distortion. The tilted setting of the isolation strip can converge the beamwidth to within 65±10°. Furthermore, the compact structural design of the components of the multi-band array base station antenna in this application significantly reduces the antenna area and material consumption, aligning with the development trend of green and lightweight multi-band array base station antennas.

[0037] Please combine Figures 1 to 3 The specific structure of the multi-band array base station antenna 100 of this application is described below.

[0038] As described above, the multi-band array base station antenna 100 of this application includes a reflective base plate 110, which includes a mounting surface. The mounting surface is the side of the reflective base plate 110 used for mounting other structures. The reflective base plate 110 is used to reflect the electromagnetic waves radiated by the multi-band array base station antenna 100, causing the electromagnetic waves to propagate in a specific direction, enhancing the directivity and gain of the multi-band array base station antenna 100, and reducing the scattering and loss of electromagnetic waves in other directions. The material of the reflective base plate 110 usually has high reflectivity, such as aluminum or copper in metallic materials, which have good conductivity and reflection performance. The reflective base plate 110 can be planar, with a simple structure, and is easy to process and install. This application does not specifically limit the thickness of the reflective base plate 110.

[0039] As described above, the multi-band array base station antenna 100 of this application includes low-frequency radiating elements 120, which can be arranged in two columns on a mounting plate. The low-frequency radiating elements 120 are key components in the multi-band array base station antenna 100 system for transmitting and receiving low-frequency electromagnetic waves. The low-frequency radiating elements 120 mainly operate in lower frequency bands, such as the bands of 2G networks, typically from several hundred MHz to several GHz. Due to the longer wavelength of low-frequency electromagnetic waves, the size of the low-frequency radiating elements 120 is relatively large, based on the relationship between the size of the multi-band array base station antenna 100 and the wavelength. The column spacing of the two columns of low-frequency radiating elements 120 can be 0.5 to 0.8 times the low-frequency wavelength, thereby balancing gain, beamwidth, and sidelobe level. The connection method between the low-frequency radiating elements 120 and the mounting plate depends on the structural type of the low-frequency radiating elements 120 and the material of the reflector plate 110; the connection can be achieved through bracket fixing or mechanical fixing. The low-frequency radiating elements 120 can be integrated modularly, allowing for rapid installation onto the mounting plate.

[0040] As described above, the multi-band array base station antenna 100 of this application includes multiple rows of high-frequency radiating elements 130, which are disposed on a mounting plate. The high-frequency radiating elements 130 are key components in the multi-band array base station antenna 100 system for transmitting and receiving high-frequency electromagnetic waves. The high-frequency radiating elements 130 typically operate in higher frequency bands, such as 1427MHz-2690MHz, to meet the demand for high-frequency spectrum resources in mobile communications and other fields. Because high-frequency electromagnetic waves have shorter wavelengths, the high-frequency radiating elements 130 are relatively smaller than the low-frequency radiating elements 120. The connection method between the high-frequency radiating elements 130 and the mounting plate also depends on the structural type of the high-frequency radiating elements 130 and the material of the reflector plate 110. A plate-like isolation structure 170 can be provided between the rows of high-frequency radiating elements 130 to reduce mutual interference between adjacent rows of high-frequency radiating elements 130.

[0041] Multiple rows of high-frequency radiating units 130 are located between two rows of low-frequency radiating units 120. The low-frequency radiating units 120 are responsible for covering lower operating frequency bands, forming multi-band coverage capability with the high-frequency radiating units 130 located between them. The two rows of low-frequency radiating units 120 are symmetrically distributed on both sides of the high-frequency radiating units 130, which helps to form a symmetrical radiation pattern and reduce pattern distortion. Placing the low-frequency radiating units 120 on the outer sides and the smaller high-frequency radiating units 130 in the middle makes full use of space.

[0042] As described above, the multi-band array base station antenna 100 of this application includes two reflective side plates 140. One side of each of the two reflective side plates 140 is connected to a mounting plate, and the reflective side plates 140 and the reflective base plate 110 can be integrally formed. The two reflective side plates 140 are located on the side of the two rows of low-frequency radiating elements 120 away from the high-frequency radiating elements 130. The two reflective side plates 140 can be connected to opposite sides of the reflective base plate 110, and the angle between the reflective side plate 140 and the mounting plate can be 90±9°, ​​that is, the reflective side plate 140 is substantially perpendicular to the reflective base plate 110. The reflective side plates 140 are located outside the two rows of low-frequency radiating elements 120 (on the side of the low-frequency radiating elements 120 away from the high-frequency radiating elements 130). Therefore, the reflective side plates 140 can reflect outwardly diffused low-frequency electromagnetic waves back to the main radiation direction and block external electromagnetic waves from entering the low-frequency radiating element 120 area, while also preventing low-frequency energy leakage from interfering with other equipment. The reflective side plate 140 can be made of aluminum alloy or galvanized steel sheet, thus achieving a balance between conductivity and mechanical strength. This application also does not specify a particular thickness for the reflective side plate 140.

[0043] As described above, the multi-band array base station antenna 100 of this application includes an isolation strip 150, which is disposed between adjacent low-frequency radiating elements 120 and high-frequency radiating elements 130. The isolation strip 150 includes a first folded plate 151, a connecting plate 152, and a second folded plate 153 connected in sequence. One side of the connecting plate 152 is connected to a mounting plate. The connection between the connecting plate 152 and the mounting plate can be made by screws, riveting, welding, or adhesive bonding, etc., without specific limitations. The first folded plate 151 is closer to the low-frequency radiating element 120 than the second folded plate 153. The first folded plate 151 is inclined toward the low-frequency radiating element 120, and the angle between the first folded plate 151 and the connecting plate 152 is 60±6°. The height of the first folded plate 151 is 0.4 to 0.5 times the height of the low-frequency radiating element 120. The angle between the second folding plate 153 and the connecting plate 152 is 90±9°, ​​and the height of the second folding plate 152 is 0.4 to 0.5 times the height of the high-frequency radiating unit 130. The specially designed isolation strip 151 can reduce the influence between the two frequency bands and decrease beam distortion. The tilted setting of the isolation strip 151 can converge the beamwidth to within 65±10°. Specifically, the isolation strip 150 can suppress interference between high-frequency and low-frequency signals. When the low-frequency radiating unit 120 and the high-frequency radiating unit 130 are close together, electromagnetic coupling will occur, affecting their respective radiation performance. The isolation strip 150 can reduce this mutual coupling by reflecting, absorbing, or changing the field distribution. The isolation strip 150 can also reduce signal crosstalk between units of different frequency bands, improving the isolation index between the low-frequency port and the high-frequency port and reducing mutual influence. The isolation strip 150 can also reduce the load effect of adjacent radiating units on the feed network, helping both the high-frequency radiating unit 130 and the low-frequency radiating unit 120 to operate in a well-matched state. Preferably, the height of the first folding plate 151 is 0.45 to 0.5 times the height of the low-frequency radiation unit 120, and the height of the second folding plate 152 is 0.45 to 0.5 times the height of the high-frequency radiation unit 130. More preferably, the height of the first folding plate 151 is slightly less than 0.5 times the height of the low-frequency radiation unit 120, and the height of the second folding plate 152 is slightly less than 0.5 times the height of the high-frequency radiation unit 130.

[0044] The first folding plate 151, the connecting plate 152, and the second folding plate 153 can be integrally formed. The material of the isolation strip 150 is mainly determined according to its functional requirements (such as electromagnetic shielding, structural support, lightweighting, etc.) and usage scenarios (such as frequency band, environmental conditions, etc.). The isolation strip 150 can be made of at least one of the following: metallic materials, metal-dielectric composite materials, and wave-absorbing materials. Metallic materials (such as aluminum alloys, copper, stainless steel, etc.) have high conductivity, which can effectively reflect and absorb electromagnetic waves, block the spatial coupling path between the high-frequency radiation unit 130 and the low-frequency radiation unit 120, and significantly improve the isolation. Metallic materials have high mechanical strength, which can stably maintain key dimensions such as fold height and spacing, and are not easily deformed even under environments such as vibration and temperature changes, thereby ensuring the consistency of isolation performance. Metallic materials can guide the surface current to flow along a preset path, avoiding current crossflow between the high-frequency radiation unit 130 and the low-frequency radiation unit 120, thereby reducing impedance mismatch and radiation pattern distortion caused by current coupling. The metal-based isolation strip 150 can be mass-produced using mature processes such as stamping and bending, ensuring easy precision control. It is also easy to connect to the metal mounting plate via welding or riveting, forming an integrated conductive structure that further enhances shielding effectiveness. Specifically, aluminum alloys are lightweight and possess good conductivity and machinability, making them suitable for most civilian and commercial multi-band array base station antennas; copper / brass offers excellent conductivity and good isolation, making it suitable for scenarios with stringent isolation requirements; galvanized steel is low-cost, high-strength, and corrosion-resistant, making it suitable for outdoor or harsh environments. Metal-dielectric composite materials combine the electromagnetic properties of metals with the structural characteristics of dielectrics, making them more suitable for scenarios requiring specific mechanical properties. Metal-plated plastics, with copper, aluminum, or other metals plated on the plastic substrate, balance lightweight design and isolation, making them suitable for complex-shaped isolation strips 150. Metal mesh / metal foil and foam composite materials are lightweight yet possess a certain level of isolation capability, making them suitable for weight-sensitive multi-band array base station antennas 100. For high-frequency or strongly coupled scenarios, absorbing materials can be used to create isolating strips 150, which absorb electromagnetic energy and reduce interference. Ferrites have good absorption properties for high-frequency electromagnetic waves and are commonly used in the microwave band. Carbon fiber composite materials combine conductivity and absorption properties with high strength and light weight, making them suitable for high-end multi-band array base station antenna designs.

[0045] The angle between the first folding plate 151 and the connecting plate 152 is approximately 60°. This angle design allows for more precise control of the electromagnetic coupling path and more effectively guides the edge current flow near the low-frequency radiation unit 120, reducing interference to the adjacent high-frequency radiation unit 130. The tilted structure can form a barrier-like field distribution, extending the propagation path of electromagnetic waves between the high-frequency radiation unit 130 and the low-frequency radiation unit 120 without significantly increasing the volume, thus reducing the energy coupling strength. By finely adjusting the angle (allowing ±6°), both the feasibility of mass production and stable isolation performance can be ensured.

[0046] The second folding plate 153 maintains a 90±9° angle with the connecting plate 152 (nearly perpendicular), which strengthens the electromagnetic barrier on the high-frequency side within the overall isolation strip 150 structure. This more directly blocks the electromagnetic wave diffusion from the high-frequency radiation unit 130 to the low-frequency radiation unit 120, especially effectively isolating high-frequency (shorter wavelength) electromagnetic waves and reducing the penetration of high-frequency energy into the low-frequency region. The second folding plate 153 also guides the surface current on the mounting plate to flow vertically, preventing the formation of a continuous current path between the high-frequency radiation unit 130 and the low-frequency radiation unit 120, thereby reducing electromagnetic coupling conducted through the reflective base plate 110.

[0047] The first folding plate 151 is inclined towards the low-frequency radiation unit 120, and the second folding plate 153 is perpendicular to the high-frequency radiation unit 130. This inclined-vertical gradient structure can form differentiated blocking for the propagation characteristics of electromagnetic waves in different frequency bands (longer wavelengths for low frequencies and shorter wavelengths for high frequencies), thus improving the isolation effect over a wide frequency range. The above design also takes into account structural stability. Compared with the first folding plate 151 (inclined towards the connecting plate 152), the second folding plate 153 (designed perpendicular to the connecting plate 152) can provide better mechanical support, reducing the deformation of the isolation strip 150 during processing or use.

[0048] In the direction perpendicular to the mounting plate, the height of the first folding plate 151 is 12–16 mm. The first folding plate 151 is close to the low-frequency radiation unit 120, and its higher height can more effectively block the propagation of low-frequency electromagnetic waves into the high-frequency region, thereby reducing coupling between high and low-frequency signals. Preferably, the height of the first folding plate 151 is 14.5–15.5 mm. More preferably, the height of the first folding plate 151 is approximately 15 mm. A height of approximately 15 mm typically corresponds to a relatively small proportion of the low-frequency wavelength (for example, in the several hundred MHz band, λ / 4 might be around 200 mm, while 15 mm is only around λ / 13), but by adjusting the tilt angle (60°±6°), maximum isolation effect can be achieved within a limited height.

[0049] In the direction perpendicular to the mounting plate, the height of the second folding plate 153 is 6–9 mm. The second folding plate 153 is close to the high-frequency radiating unit 130; its lower height provides some lateral isolation while ensuring normal high-frequency signal radiation, avoiding excessive obstruction of the high-frequency radiation pattern. Preferably, the height of the second folding plate 153 is 7.5–8.5 mm. More preferably, the height of the second folding plate 153 is approximately 8 mm. A height of approximately 8 mm may be close to λ / 20–λ / 40 for high-frequency bands (e.g., 2–6 GHz), providing isolation without significantly affecting the impedance bandwidth and gain of the high-frequency radiating unit 130.

[0050] In the direction parallel to the mounting plate, the shortest distance between the first folding plate 151 and the second folding plate 153 is less than or equal to 10 mm, that is, the width of the connecting plate 152 is less than or equal to 10 mm. Preferably, the shortest distance between the first folding plate 151 and the second folding plate 153 is 5 to 10 mm. More preferably, the shortest distance between the first folding plate 151 and the second folding plate 153 is 10 mm. The 10 mm distance can form an "electromagnetic groove" between the first folding plate 151 and the second folding plate 153, effectively blocking the surface wave coupling between the high-frequency radiating unit 130 and the low-frequency radiating unit 120. A suitable distance allows the high-frequency radiation pattern to form a cleaner "recess" on the side pointing towards the low-frequency radiating unit 120, reducing the influence of the low-frequency beam on the shape of the high-frequency beam. This is crucial for maintaining stable coverage of the multi-band array base station antenna 100 in a wide frequency band.

[0051] The thickness of the isolation strip 150 is 1 ± 0.1 mm. A thickness of approximately 1 mm is sufficient for the isolation strip 150 to form an effective electromagnetic barrier, reducing field coupling between the high-frequency radiating unit 130 and the low-frequency radiating unit 120. 1 mm is a commonly used sheet metal thickness, facilitating stamping and bending. Too thin (<0.9 mm) may deform during installation and transportation, affecting dimensional accuracy; too thick (>1.1 mm) increases weight and bending difficulty. The aforementioned thickness, along with the height of the first folding plate 151, the height of the second folding plate 153, and the spacing between the first folding plate 151 and the second folding plate 153, collectively affects the overall isolation performance of the isolation strip 150.

[0052] The two ends of the isolation strip 150 are located at the first and last low-frequency radiating elements 120 in the same column, and the two ends of the isolation strip 150 are located at the first and last high-frequency radiating elements 130 in the same column. In other words, the two ends of the isolation strip 150 are aligned with the first and last low-frequency radiating elements 120 in the same column, and also with the first and last high-frequency radiating elements 130 in the same column. This design allows the isolation strip 150 to form a continuous electromagnetic barrier along the entire length of the array of high- and low-frequency radiating elements 120 and low-frequency radiating elements 120, avoiding "gaps" at the ends of the array, thereby preventing electromagnetic waves from diffracting from the ends and causing coupling. The ends of the multi-band array base station antenna 100 array typically have stronger edge currents and field distortions, and the fully covered isolation strip 150 can effectively suppress this effect. At the same time, the aligned ends ensure the symmetry of the structure on both sides of the array, which helps to form a symmetrical horizontal radiation pattern and reduce beam offset.

[0053] The multi-band array base station antenna 100 of this application includes two dielectric substrates 160. The two dielectric substrates 160 are suspended above two rows of high-frequency radiating elements 130 near the low-frequency radiating element 120. The side of the high-frequency radiating element 130 facing away from the mounting plate is above the dielectric substrate 130. The angle between the two dielectric substrates 160 and the mounting plate is 0±1°, meaning the dielectric substrates 160 are essentially horizontal with the mounting plate. Because the height of the outer casing of the multi-band array base station antenna 100 is limited by the size of the low-frequency radiating element 120, the height of the outer casing for the high-frequency radiating element 130 is too high, resulting in a generally narrow horizontal beamwidth, averaging only about 60°. The dielectric substrates 160 act as a simulated outer casing, adjusting the horizontal beamwidth of the high-frequency radiating element 130 to an average of 65°. Specifically, the dielectric substrate 160 can suppress the mutual coupling between the high-frequency and low-frequency radiating elements 120 and the low-frequency radiating element 120, effectively blocking or changing the coupling path of electromagnetic waves in the two frequency bands and improving port isolation. The dielectric substrate 160 can adjust the shape of the high-frequency beam, improve the front-to-back ratio and sidelobe characteristics, and especially reduce the influence of low-frequency radiation on the high-frequency radiation pattern. It can also reduce surface wave interference, cut off the propagation of high-frequency signals on the surface of the mounting plate, and reduce surface wave loss and radiation pattern distortion. The multi-band array base station antenna 100 of this application includes multiple support columns 180, which suspend and support the two dielectric substrates 160 above the high-frequency radiating element 130.

[0054] The center lines of the high-frequency radiation units 130 in the same row are basically coincident. The distance between the center line of the dielectric substrate 160 and the center line of the high-frequency radiation unit 130 below it is 0 to 1 mm. That is, the dielectric substrate 160 and the high-frequency radiation unit 130 below it are basically directly opposite each other. This enables the dielectric substrate 160 to accurately control the high-frequency beam.

[0055] The column spacing of any two adjacent columns of high-frequency radiating units 130 is equal, defined as A, where A is 0.5 to 0.8 times the wavelength of the high-frequency radiating unit 130. In some embodiments, A is 50 to 80 mm. Preferably, A is 60 to 70 mm. More preferably, A is approximately 65 mm. The width of the dielectric plate 160 is 1A to 2A, that is, in some preferred embodiments, the width of the dielectric plate 160 is approximately 65 to 130 mm. The dielectric plate 160 with a width of 1A to 2A can symmetrically cover the two columns of high-frequency radiating units 130, avoiding pattern distortion caused by uneven local shielding. The dielectric plate 160 can precisely cover the core radiation area of ​​the two columns of high-frequency radiating units 130, uniformly suppressing mutual coupling between units. The dielectric plate 160 can block the diffusion of high-frequency energy to the low-frequency radiating unit 120 without interfering with low-frequency radiation due to excessive width. The width of the dielectric substrate 160 is designed in proportion to the A-value (the column spacing between two adjacent columns of high-frequency radiating units 130), which can accommodate high-frequency arrays with different A-values. If the A-value needs to be changed due to frequency band adjustment, only the size of the dielectric substrate 160 needs to be scaled proportionally, without the need to redesign the overall layout, thus reducing modification costs. Preferably, the width of the dielectric substrate 160 can be 1.5A to 2A. More preferably, the width of the dielectric substrate 160 can be 1.8A to 2A.

[0056] The thickness of the dielectric substrate 160 is 1–2 mm, thus enabling it to function effectively while occupying minimal space. Preferably, the thickness of the dielectric substrate 160 is 1.5–2 mm. More preferably, the thickness of the dielectric substrate 160 is 2 mm. The 2 mm thickness of the dielectric substrate 160 provides sufficient mechanical strength and stability, forming a reasonable thickness ratio with the isolation strip 150 (approximately 1 mm thick), and avoiding excessive obstruction.

[0057] The shortest distance between the dielectric substrate 160 and the mounting plate is A. By unifying the spatial position of the dielectric substrate 160 with the dimensional reference of the electrical layout of the high-frequency radiation unit 130, local suppression imbalances at the electrical level are avoided, the impact of mechanical deviations is reduced, and the frequency band expansion requirements are accommodated, thus achieving the design goal of uniform suppression effect of the dielectric substrate 160 on the high-frequency radiation unit 130.

[0058] The dielectric substrate 160 is made of a material with a dielectric constant of 3 to 5, that is, the dielectric constant of the dielectric substrate 160 is 3 to 5. Preferably, the dielectric substrate 160 is made of a material with a dielectric constant of 4 to 4.8. More preferably, the dielectric substrate 160 is made of FR4 material with a dielectric constant of 4.4. The matching relationship between the various parameters of the dielectric substrate 160 and the A value (the column spacing between two adjacent columns of high-frequency radiating elements 130) can partially offset the influence of the dielectric constant variation.

[0059] The two ends of the dielectric substrate 160 are located at the first and last low-frequency radiating units 120 in the same column, and the two ends of the dielectric substrate 160 are located at the first and last high-frequency radiating units 130 in the same column. In other words, the two ends of the dielectric substrate 160 are aligned with the positions of the first and last low-frequency radiating units 120 in the same column, and at the same time, these two ends are also aligned with the positions of the first and last high-frequency radiating units 130 in the same column. That is, the dielectric substrate 160 covers the entire length of the high-frequency radiating units 130 and the low-frequency radiating units 120 from beginning to end, forming a continuous barrier. The shielding dielectric substrate 160 completely covers the array length of the high-frequency radiating units 130 and the low-frequency radiating units 120, avoiding "field leakage" at both ends of the array and preventing high-frequency energy diffracting from the ends and affecting low-frequency performance. The end alignment design ensures that the electrical environment at both ends of the high-frequency radiating unit 130 and the low-frequency radiating unit 120 array is consistent, which helps to form a symmetrical horizontal radiation pattern and reduce beam tilt. The dielectric substrate 160 is uniformly distributed throughout the array length of the high-frequency radiation unit 130 and the low-frequency radiation unit 120, so that the high-frequency and low-frequency isolation at each position is consistent and "edge hot spots" are avoided.

[0060] The above embodiments are only used to illustrate the present application and are not intended to limit it. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included within the protection scope of the present application.

Claims

1. A multi-band array base station antenna, characterized in that, The multi-band array base station antenna includes: Reflective base plate, including mounting plate surface; Two rows of low-frequency radiating units are disposed on the mounting plate surface; Multiple rows of high-frequency radiating units are disposed on the mounting plate, with the multiple rows of high-frequency radiating units located between two rows of low-frequency radiating units; Two reflective side plates are connected to the mounting plate surface on one side respectively. The two reflective side plates are located on the side of the two rows of low-frequency radiation units away from the high-frequency radiation units. The angle between the reflective side plates and the mounting plate surface is 90±9°. An isolation strip is disposed between adjacent rows of the low-frequency radiation units and the high-frequency radiation units. The isolation strip includes a first folding plate, a connecting plate, and a second folding plate connected in sequence. One side of the connecting plate is connected to the mounting plate. The first folding plate is closer to the low-frequency radiation unit than the second folding plate. The first folding plate is inclined towards the low-frequency radiation unit, and the angle between the first folding plate and the connecting plate is 60±6°. The height of the first folding plate is 0.4 to 0.5 times the height of the low-frequency radiation unit. The angle between the second folding plate and the connecting plate is 90±9°, ​​and the height of the second folding plate is 0.4 to 0.5 times the height of the high-frequency radiation unit. Two dielectric plates are suspended above the two rows of high-frequency radiation units near the low-frequency radiation unit. The high-frequency radiation units are located on the side of the high-frequency radiation unit that is away from the mounting plate. The angle between the dielectric plate and the mounting plate is 0 to 1°.

2. The multi-band array base station antenna according to claim 1, characterized in that, The height of the first folding plate is 12-16 mm, and the height of the second folding plate is 6-9 mm.

3. The multi-band array base station antenna according to claim 1, characterized in that, In the direction parallel to the mounting plate surface, the shortest distance between the first folding plate and the second folding plate is less than or equal to 10 mm.

4. The multi-band array base station antenna according to claim 1, characterized in that, The isolation strip has a thickness of 1±0.1mm and is made of at least one of the following: metal material, metal-dielectric composite material, and microwave absorbing material.

5. The multi-band array base station antenna according to claim 1, characterized in that, The two ends of the isolation strip are located at the first and last two low-frequency radiation units in the same column, and the two ends of the isolation strip are located at the first and last two high-frequency radiation units in the same column.

6. The multi-band array base station antenna according to claim 1, characterized in that, The offset distance between the center line of the dielectric plate and the center line of the high-frequency radiation unit below it is 0 to 1 mm.

7. The multi-band array base station antenna according to claim 1, characterized in that, The column spacing between any two adjacent columns of the high-frequency radiation units is equal, and the column spacing is A, where A is 0.5 to 0.8 times the wavelength of the high-frequency radiation unit. The width of the dielectric substrate is 1A to 2A, the thickness of the dielectric substrate is 1 to 2 mm, and the shortest distance between the dielectric substrate and the mounting plate is A.

8. The multi-band array base station antenna according to claim 7, characterized in that, A is 50-80 mm.

9. The multi-band array base station antenna according to claim 1, characterized in that, The dielectric constant of the dielectric substrate is 3 to 5.

10. The multi-band array base station antenna according to claim 1, characterized in that, The two ends of the dielectric plate are located at the first and last two low-frequency radiation units in the same column, and the two ends of the dielectric plate are located at the first and last two high-frequency radiation units in the same column.

Images