EP4087057B1

EP4087057B1 - Array antenna

Info

Publication number: EP4087057B1
Application number: EP20909313.7A
Authority: EP
Inventors: Peitao Liu; Mingchao Li; Litao CHEN; Qinyuan WANG; Jianjun YOU
Original assignee: Comba Telecom Technology Guangzhou Ltd
Current assignee: Comba Telecom Technology Guangzhou Ltd
Priority date: 2019-12-31
Filing date: 2020-08-20
Publication date: 2025-07-02
Anticipated expiration: 2040-08-20
Also published as: WO2021135266A1; EP4087057C0; CN111063997A; CN111063997B; EP4087057A1; EP4087057A4

Description

TECHNICAL FIELD

The present application relates to the field of mobile communication technology, and in particular, to an array antenna.

BACKGROUND

5G mobile communication technology has already accumulated after several years of development. 5G antenna generally uses large-scale array antenna with multiple signal channels, so the number of corresponding components, such as RF component and radiation unit, is also further increased. The current main 5G large-scale array antenna mainly uses sheet metal, die-casting, or PCB oscillator as radiation unit, and is fed by PCB board. In addition, additional RF component (such as RF component) is welded and installed on the back of the antenna to achieve the corresponding antenna index.
Several necessary components of the existing antenna are generally assembled separately, and finally assembled into the whole machine by screws and rivets. Because there are many components of the array antenna, the assembly way of existing antenna is not only complex, but also leads to the large size and weight of the whole antenna.
Chinese patent application published No. CN110323556A discloses an active antenna unit for a base station, wherein the active antenna unit comprises a filter component comprising a plurality of filter units. The base station antenna includes an antenna substrate and N sets of antenna element groups. The N sets of antenna element groups are arranged in an array on the first main surface of the antenna substrate, and the base station antenna is disposed above the filter component. Each set of the antenna element groups is connected to the corresponding filter unit through the same power dividing line.
Chinese patent application published No. CN110011072A discloses an integrated Massive MIMO antenna including a reflector, one side of which is provided with a power distribution network PCB board, and the other side of the reflector is provided with a calibration network PCB board, a power distribution network PCB board, a reflection board, and a calibration network PCB. The document further describes antenna performance test points, filter performance test points and antenna performance test points for the integrated Massive MIMO antenna.

SUMMARY

Based on this, it is necessary to provide an array antenna with light weight.
An array antenna comprises:

an antenna oscillator module including a dielectric substrate, a feed network line layer formed on a surface of the dielectric substrate and a plurality of radiation units disposed on one side of the dielectric substrate and fed by the feed network line layer;
a shielding cavity formed on one side of the dielectric substrate facing away from the radiation unit;
a plurality of dielectric filter modules disposed within the shielding cavity, and each shielding cavity housing at least two of the dielectric filter modules, an output of each of the dielectric filter modules being electrically connected to the feed network line layer;
- a reflective plate affixed to one side of the dielectric substrate facing away from the radiation unit; and
- a shield with an opening on one side, wherein, the shield is provided on a surface of the reflective plate facing away from the antenna oscillator module and cooperating with the reflective plate to form the shielding cavity,
- wherein, an inner wall of the shield is provided with a conductive foam abutting against the dielectric filter module.

In one embodiment, the dielectric substrate comprises a feed substrate and a radiation substrate disposed on one side of the feed substrate and integrally formed with the feed substrate, wherein, the feed network line layer is formed on a surface of the feed substrate, the radiation substrate is coated with a metal layer on a surface to form the radiation unit.
In one embodiment, the feed network line layer is disposed on a surface of the feed substrate facing away from the radiation unit.
Alternatively, the feed network line layer is disposed on a surface of the feed substrate facing the radiation unit.
In one embodiment, the array antenna further comprises a circuit board, wherein, the plurality of dielectric filter modules are integrated in the circuit board, and the outputs of the plurality of dielectric filter modules are electrically connected to the feed network line layer through the circuit board.
In one embodiment, the circuit board is provided with RF connectors and feed pins corresponding to the plurality of dielectric filter modules on opposite sides, wherein, the feed network line layer is formed with feed holes, the feed pins are inserted in the feed holes to electrically connect the plurality of dielectric filter modules to the feed network line layer.
In one embodiment, the dielectric substrate is formed with raised ribs on a surface toward the reflective plate, and the ribs are abutted against the reflective plate.
In one embodiment, the shield is coated with a conductive adhesive on an end surface of the opening.
In the above array antenna, the feed network line layer can be formed on the surface of the dielectric substrate by means of coating, etc. Therefore, it is equivalent to integrating the feed network and radiation unit of the conventional antenna on the dielectric substrate. When assembling, there is no need to weld and screw the feed network, which helps to simplify the structure. Further, the shielding cavity provides shielding to the dielectric filter module inside, so multiple dielectric filter modules with the shielding cavity can be functionally equivalent to the traditional multiple dielectric filters. Moreover, each shielding cavity houses at least two dielectric filter modules, so the number of shielding cavities can be much less than the number of dielectric filter module. Compared with the traditional way of directly mounting dielectric filters, more metal shielding cavities can be omitted. Therefore, the above array antenna can achieve light weight.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG 1 is a schematic diagram of the structure of the array antenna in the preferred embodiment of the present invention.
FIG 2 is an exploded view of one angle of the array antenna shown in FIG 1.
FIG 3 is an exploded view of another angle of the array antenna shown in FIG 1.
FIG 4 is a schematic diagram of the structure of one surface of the antenna oscillator module in one embodiment of the present invention.
FIG 5 is a schematic diagram of the structure of another surface of the antenna oscillator module shown in FIG 4.
FIG 6 is a schematic diagram of the structure of one surface of the antenna oscillator module in another embodiment of the present invention.
FIG 7 is a schematic diagram of the structure of the shield in the array antenna shown in FIG 1.

DETAILED DESCRIPTION

In order to facilitate the understanding of the present application, the present application will be more fully described below with reference to the relevant accompanying drawings. Preferred embodiments of the present application are given in the accompanying drawings. However, the application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided for the purpose of providing a more thorough and comprehensive understanding of the disclosure of the present application.
It is noted that when an element is considered to be "fixed" to another element, it may be directly on the other element or there may also be a centered element. When an element is considered to be "attached" to another element, it can be directly attached to another element or there may also be a centered element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are used for illustrative purposes only.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art of the application. The terms used herein in the specification of the present application are for the purpose of describing specific embodiments only and are not intended to limit the application. The term "and/or" as used herein includes any and all combinations of one or more of the relevant listed items.
Referring to FIGS. 1, 2, and 3, an array antenna 10 in the preferred embodiment of the present application includes an antenna oscillator module 100, a shielding cavity 200, and a dielectric filter module 300.
Referring to FIGS. 4 and 5, the antenna oscillator module 100 includes a dielectric substrate 110, a feed network line layer 120, and a radiation unit 130. The antenna oscillator module 100 generally has multiple signal channels. For example, there are common 32 channels, 64 channels. Each signal channel contains at least one radiation unit 130. As shown in FIGS. 2 and 3, in the embodiment, the number of radiation unit 130 is 96, and each signal channel contains three radiation units 130. Therefore, the array antenna 10 is a 32-channel antenna.
The dielectric substrate 110 is a one-piece structure, and its material can be plastic, resin, etc. Usually, the dielectric substrate 110 is molded in one piece by injection molding. The feed network line layer 120 is formed on the surface of the dielectric substrate 110. The feed network line layer 120 can integrate functional circuit such as divider circuit, filter circuit, etc., which can be used to feed the radiation unit 120, and is therefore equivalent to a conventional feed network. Specifically, the feed network line layer 120 can be formed on the surface of the dielectric substrate 110 by means of selective plating, LDS (laser direct forming technology) and other surface metal forming, and can be made of copper, silver and other good conductors.
The radiation unit 130 is used for receiving and radiating electromagnetic wave signals outward, generally using a dual-polarized radiation unit. The radiation unit 130 is provided on one side of the dielectric substrate 110, and is fed by the feed network line layer 120. Among them, the feed network line layer 120 can be directly fed to the radiation unit 130, can also be coupled to the radiation unit 130 for feed. Specifically, when the feed network line layer 120 is formed, a feed structure line layer 140 may also be formed on the dielectric substrate 110 at the same time, and the feed structure line layer 140 is supported by the dielectric substrate 110, which is equivalent to the traditional feed balun and feed column.
Each array antenna 10 may include only one antenna oscillator module 100, that is, multiple radiation units 130 are disposed on the same dielectric substrate 110; may also include a plurality of antenna oscillator module 100, that is, the plurality of radiation units 130 are disposed on different dielectric substrate 110 and then joined together. As shown in FIGS. 2 and 3, specifically in this embodiment, each array antenna 10 includes 8 antenna oscillator modules 100, and each dielectric substrate 110 is provided with 12 radiation units 130. 8 dielectric substrate 110 are joined each other, thereby forming an antenna oscillator module 100 with 96 radiation units 130.
The radiation unit 130 can be in the form of metal oscillator structure, PCB oscillator structure, plastic metallization oscillator and metal laminate structure. Referring again to FIGS. 4 and 5, in one embodiment, the dielectric substrate 110 includes a feed substrate 111 and a radiation substrate 113 located on one side of the feed substrate 111 and integrally formed with the feed substrate 111. The feed network line layer 120 is formed on the surface of the feed substrate 111, and the surface of the radiation substrate 113 is coated with a metal layer (not marked in the figure) to form the radiation unit 130.
Specifically, the metal layer can also be formed by means of selective plating, LDS (laser direct forming technology) and other surface metal forming way. The radiation substrate 113 supports the metal layer, and forms the radiation unit 130 together with the metal layer together. At this time, the radiation unit 130 and the dielectric substrate 110 constitute a one-piece structure. In other words, the traditional radiation unit and feed network can be integrated on the dielectric substrate 110, so the structure of the antenna oscillator module 100 can be simplified, and its volume and weight can be significantly reduced.
The radiation substrate 113 can be a hollow column-shaped projection formed by a local recess from the feed substrate 111. The metal layer forming the radiation unit 130 is attached to the outer surface of the column-shaped projection. Specifically, the hollow column-shaped projection may be cube-shaped or cylindrical, i.e., its cross-section is rectangular or circular. Wherein, the feed structure line layer 140 may be supported by the inner wall of the column-shaped projection and extend along the inner wall toward the radiation unit 130. By making a local recess in the feed substrate 111 to form the support structure of the radiation unit 130, the structure of the dielectric substrate 110 can be made more reasonable and the yield rate of injection molding is better.
Further, the feed network line layer 120 can be located either on the same or different side of the dielectric substrate 110 as the radiation unit 130. As shown in FIGS. 4 and 5, in one embodiment, the feed network line layer 120 is located on the surface of the feed substrate 111 facing away from the radiation unit 130. Meanwhile, the feed network line layer 120 may be integrally formed with the feed structure line layer 140.
As shown in FIG 6, in another embodiment, the feed network line layer 120 is disposed on a surface of the feed substrate 111 toward the radiation unit 130. Meanwhile, the feed network line layer 120 may be electrically connected to the feed structure line layer 140 by opening a metallized perforation.
Referring again to FIGS. 1 to 3, a shielding cavity 200 is formed on one side of the dielectric substrate 110 facing away from the radiation unit 130. The shielding cavity 200 may be a closed cavity structure mounted on one side of the dielectric substrate 110 by welding, screwing, etc.; the shielding cavity 200 may also be a cavity structure with a shielding function obtained by forming integrally with the dielectric substrate 110 and metallizing the surface; the shielding cavity 200 may also be a closed cavity structure formed by a semi-closed structure cooperating with the dielectric substrate 110. The shielding cavity 200 can play the role of electrostatic shielding, equivalent to the metal shielding cavity of traditional dielectric filter.
In this embodiment, the array antenna 10 also includes a reflective plate 500, the reflective plate 500 is affixed to the side of the dielectric substrate 110 facing away from the radiation unit 130.
Specifically, the reflective plate 500 is generally a metal reflective plate, which can reflect the electromagnetic wave signal several times, thus enhancing the efficiency of signal transmitting and receiving of the radiation unit 130. The surface profile of the reflective plate 500 is generally substantially the same as the surface profile of the dielectric substrate 110, and the surfaces of both are disposed opposite each other. The reflective plate 500 can be screwed, welded and other ways to achieve installation with the dielectric substrate 110.
Referring again to FIG 6, in one embodiment, a raised rib 1112 is formed on the surface of the dielectric substrate 110 facing the reflective plate 500, and the rib 1112 abuts the reflective plate 500.
Specifically, the rib 1112 is formed on the feed substrate 111. The rib 1112 may be distributed in a circular pattern on the surface of the feed substrate 111 or may extend in a straight line on the surface of the feed substrate 111. On the one hand, the rib 1112 may serve to strengthen the mechanical strength of the feed substrate 111. On the other hand, the rib 1112 may support the reflective plate 500 so as to maintain a stable gap between the reflective plate 500 and the feed substrate 111. When the feed network line layer 120 is located on the side of the feed substrate 111 facing away from the radiation unit 130, it can ensure the isolation of the feed network line layer 120 from the reflective plate 500.
Further, in this embodiment, the array antenna 10 also includes a shield 600 with an opening on one side, and the shield 600 is covered on the surface of the reflector plate 500 facing away from the antenna oscillator module 100 and cooperates with the reflective plate 500 to form the shielding cavity 200.
Specifically, the shield 600 can be in the shape of a cube, a hemisphere or a semi-cylindrical shape, etc., with an opening on one side. The shield 600 can be formed directly from the metal material; or it can be formed by the dielectric material first, and then the surface of the dielectric material can be metallized. The shield 600 is generally fastened to the reflective plate 500 by screws. At this time, the reflective plate 500 acts as a sidewall of the shielding cavity 200. Therefore, the shield 600 can also omit a sidewall compared with the conventional metal shielding cavity, so the weight can be further reduced.
Referring together to FIG 7, specifically in this embodiment, the end surface of the opening of the shield 600 is covered with a conductive adhesive 610. The conductive adhesive 610 can make good contact with the edge of the opening of the shield 600, thus ensuring the shielding effect of the shielding cavity 200.
The dielectric filter module 300 is equivalent to the filter body structure after the traditional dielectric filter omitting the metal shielding cavity. There are multiple dielectric filter modules 300, and the output of each dielectric filter module 300 is electrically connected to the feed network line layer 120. The dielectric filter module 300 is used to filter the electromagnetic wave signal received or radiated by each radiation unit 130. Thus, the dielectric filter modules 300 correspond to the number of signal channels of the array antenna 10. For example, if the array antenna 10 shown in FIG 1 has 32 signal channels, the number of dielectric filter modules 300 is 32.
Further, a plurality of dielectric filter modules 300 are provided in the shielding cavity 200, and each shielding cavity 200 houses at least two dielectric filter modules 300. Depending on the size of the antenna, one or more shielding cavities 200 may be included in each array antenna 10. For example, the array antenna 10 shown in FIG 1 includes two shielding cavities 200, each shielding cavity 200 contains 16 filter modules 300.
In other words, one shielding cavity 200 can provide electrostatic shielding effect on a plurality of dielectric filter modules 300, so the number of shielding cavities 200 can be much less than the number of dielectric filter modules 300. In conventional technology, for 32-channel antenna, 32 filters need to be installed, and each filter has a metal shielding cavity. In this scheme, for 32-channel array antenna 10, only two shielding cavities 200 need to be installed. Therefore, compared with the traditional way, the array antenna 100 can omit more metal shielding cavities, thus simplifying the installation operation and reducing the weight.
Referring again to FIG 7, specifically in this embodiment, the inner wall of the shield 600 is provided with a conductive foam 620 that abuts the dielectric filter module 300.
The conductive foam 620 extends along the length of the shield 600, thus covering all the dielectric filter modules 300 in the shielding cavity 200. Thus, the conductive foam 620 connects the shield 600 to the surface of each dielectric filter module 300, so that each dielectric filter module 300 is well grounded, thus suppressing high frequency clutter caused by surface current radiation.
In this embodiment, the array antenna 10 also includes a circuit board 400, a plurality of dielectric filter modules 300 are integrated in the circuit board 400, and the outputs of the plurality of dielectric filter modules 300 are electrically connected to the feed network line layer 120 through the circuit board 400.
The plurality of dielectric filter modules 300 can be positioned and soldered on the circuit board 400 first, and then the circuit board 400 integrated with the dielectric filter modules 300 as a whole is connected to the feed network line layer 120. Therefore, it is only necessary to align the circuit board 400 as a whole with the feed network line layer 12, instead of repeating the positioning of each dielectric filter module 300, so it can make the assembly more convenient. Among them, the number of circuit boards 400 can be the same as the number of shielding cavities 200, or all dielectric filter modules 300 can be integrated on the same circuit board 400.
The array antenna 10 shown in FIGS 1 to 3 has 2 circuit boards 400, and each circuit board 400 has 16 dielectric filter modules 300 integrated thereon. The shielding cavity 200 holds the corresponding circuit board 400 on the reflective plate 500.
Further, in this embodiment, the circuit board 400 is provided with a RF connector 410 and a feed pin 420 on opposite sides, and the RF connector 410 and feed pin 420 correspond to the plurality of dielectric filter modules 300 one by one. The feed network line layer 120 is formed with feed holes (not shown), and the feed pin 420 is inserted in the feed hole to electrically connect the plurality of dielectric filter modules 300 to the feed network line layer 120.
Specifically, the RF connector 410 and the feed pin 420 are connected to the input and output of the corresponding dielectric filter module 300, respectively. The feed hole on the feed network line layer 120 may be metallized via hole that is electrically conductive. Moreover, the position of the feed hole corresponds to the position of the feed pin 420. The reflective plate 500 is provided with avoidance hole for avoidance of the feed pin 420 (not shown). Upon assembling, the feed pin 420 is inserted into the corresponding feed hole, the positioning and installation of the board 400 is quickly realized, so the assembly is more convenient.
The RF connector 410 can be used with the plug interface of the coaxial feed to facilitate the connection between the dielectric filter module 300 and the signal transceiver device of the base station. Among them, the RF connector 410 generally protrudes to the outside of the shielding cavity 200, and the side wall of the shielding cavity 200 is opened with a through hole 210 for RF connector 410 to pass through.
The array antenna 10 described above, the feed network line layer 120 may be formed on the surface of the dielectric substrate 110 by means of coating, etc. Therefore, it is equivalent to integrating the feed network and radiation unit 130 of the conventional antenna on the dielectric substrate 110. When assembling, there is no need to weld and screw the feed network and other operations, which helps to simplify the structure. Further, the shielding cavity 200 provides shielding to the dielectric filter module 300 inside, so the plurality of dielectric filter modules 300 with the shielding cavity 200 can be functionally equivalent to the traditional multiple dielectric filters. Moreover, each shielding cavity 200 houses at least two dielectric filter modules 300, so the number of shielding cavities 200 can be much less than the number of dielectric filter modules 300. Compared with the traditional way of directly mounting dielectric filters, a larger number of metal shielding cavities can be omitted. As a result, the above array antenna 10 can achieve light weight.
Each technical feature of the above described embodiment can be combined in any way, for the sake of concise description, not all possible combinations of each technical feature of the above described embodiment are described. However, as long as the combination of these technical features are not contradictory, it should be considered as the scope of this description.
The above described embodiments express only several embodiments of the present application with more specific and detailed descriptions, but they are not to be construed as a limitation of the scope of the application. It should be noted that for a person of ordinary skilled in the art, a number of deformations and improvements can be made without departing from the scope of the present application. Therefore, the scope of protection of the present application shall be subject to the attached claims.

Claims

An array antenna (10), comprising:
an antenna oscillator module (100) including a dielectric substrate (110), a feed network line layer (120) formed on a surface of the dielectric substrate (110) and a plurality of radiation units (130) disposed on one side of the dielectric substrate (110) and fed by the feed network line layer (120);

a shielding cavity (200) formed on one side of the dielectric substrate (110) facing away from the radiation unit (130); and

a plurality of dielectric filter modules (300) disposed within the shielding cavity (200), and each shielding cavity (200) housing at least two of the dielectric filter modules (300), an output of each of the dielectric filter modules (300) being electrically connected to the feed network line layer (120);

a reflective plate (500) affixed to one side of the dielectric substrate (110) facing away from the radiation unit (130);

a shield (600) with an opening on one side, wherein, the shield (600) is provided on a surface of the reflective plate (500) facing away from the antenna oscillator module (100) and cooperating with the reflective plate (500) to form the shielding cavity (200);

wherein, an inner wall of the shield (600) is provided with a conductive foam (620) abutting against the dielectric filter module (300).
The array antenna (10) according to claim 1, wherein, the dielectric substrate (110) comprises a feed substrate (111) and a radiation substrate (113) disposed on one side of the feed substrate (111) and integrally formed with the feed substrate (111), wherein, the feed network line layer (120) is formed on a surface of the feed substrate (111), the radiation substrate (113) is coated with a metal layer on a surface to form the radiation unit (130).
The array antenna (10) according to claim 2, wherein, the feed network line layer (120) is disposed on a surface of the feed substrate (111) facing away from the radiation unit (130),
or, the feed network line layer (120) is disposed on a surface of the feed substrate (111) facing the radiation unit (130).
The array antenna (10) according to claim 1, further comprising: a circuit board (400), wherein, the plurality of dielectric filter modules (300) are integrated in the circuit board (400), and the outputs of the plurality of dielectric filter modules (300) are electrically connected to the feed network line layer (120) through the circuit board (400).
The array antenna (10) according to claim 4, wherein, the circuit board (400) is provided with RF connectors (410) and feed pins (420) corresponding to the plurality of dielectric filter modules (300) one by one on opposite sides, wherein, the feed network line layer (120) is formed with feed holes, the feed pins (420) are inserted in the feed holes to electrically connect the plurality of dielectric filter modules (300) to the feed network line layer (120).
The array antenna (10) according to claim 1, wherein, the dielectric substrate (110) is formed with raised ribs (1112) on a surface toward the reflective plate (500), and the ribs are abutted against the reflective plate (500).
The array antenna (10) according to claim 1, wherein, the shield (600) is coated with a conductive adhesive (610) on an end surface of the opening.