CN113644409A - A small base station broadband antenna - Google Patents

Abstract

Translated fromChinese

本申请提供一种小基站宽频天线，包括天线单元和金属载体，天线单元设置在金属载体的边缘位置。其中，天线单元包括：辐射体、电路板以及电流路径枝节。辐射体连接电路板，以通过电路板设置在金属载体上；电流路径枝节为连接辐射体金属片结构，电流路径枝节平行于金属载体；所述电流路径枝节上流通馈电电流形成构造电流，使所述辐射体上馈电电流分布路径与所述金属载体上靠近中心一侧的地电流方向相反；以及形成抵消所述辐射体上的反向电流的补偿电流路径。本申请通过构造天线补偿辐射电流的方式，改善辐射圆度，且结构简单，性能稳定，安装方便，解决现有宽频天线的辐射圆度差的问题。

The present application provides a small base station broadband antenna, which includes an antenna unit and a metal carrier, and the antenna unit is arranged at the edge of the metal carrier. Wherein, the antenna unit includes: a radiator, a circuit board and a current path branch. The radiator is connected to the circuit board so as to be set on the metal carrier through the circuit board; the branch of the current path is a metal sheet structure connecting the radiator, and the branch of the current path is parallel to the metal carrier; the feeding current flows on the branch of the current path to form a structural current, so that the The feeding current distribution path on the radiator is opposite to the ground current on the side of the metal carrier near the center; and a compensation current path is formed to cancel the reverse current on the radiator. The present application improves the radiation circularity by constructing the antenna to compensate the radiation current, and has the advantages of simple structure, stable performance and convenient installation, and solves the problem of poor radiation circularity of the existing broadband antenna.

Description

Broadband antenna of small base station

The present application claims priority of the chinese patent application having application number 202010346285.X entitled "a small base station wideband antenna" filed by the chinese patent office on 27/4/2020, which is incorporated herein by reference in its entirety.

Technical Field

The application relates to the technical field of antennas, in particular to a broadband antenna for a small base station.

Background

The small base station, also called a micro base station, is a base station device with low transmitting power and small coverage, and can share the load of the macro base station and improve the network problems of signal blind spots, weak coverage and the like. In order to be compatible with 3G, 4G and 5G network systems, the small base station antenna requires wideband, i.e. can support multiple frequency bands.

To further increase the transmission rate, a Multiple-antenna (MIMO) technique is applied to the small base station. Because high isolation between adjacent bands in the antenna needs to be ensured, interference between adjacent antenna radiation units is avoided, and diversity gain and system channel capacity are improved, the small base station omnidirectional antenna is usually placed at the edge of a metal carrier (rectangular or circular), but the distribution of antenna reference ground current is asymmetric, so that the signal radiation quality is affected by the current distribution disorder of a broadband antenna at high frequency, the radiation roundness of the antenna at high frequency is deteriorated, and the realization of large-scale coverage is not facilitated.

In order to improve the radiation roundness of the broadband antenna, the prior art can optimize the broadband roundness by changing the antenna structure or the coupling feeding manner. For example, chinese patent publication No. CN107925151A discloses a method of improving roundness by using a coupled feeding mode and making current distribution of a metal carrier ground relatively symmetrical through an asymmetrical antenna structure; chinese patent publication No. CN106941213A discloses a method for adjusting radiation directivity of an antenna radiation unit by adjusting positions of a plurality of paired feed points and ground points on a sheet-shaped radiator; and chinese patent publication No. CN109216917A, which discloses a method for generating an omnidirectional radiation pattern in a wide bandwidth range by the center-fed tapered ground broadband planar inverted-F antenna described in the patent.

However, the above methods all improve the complexity of the radiator or the circuit structure, are not suitable for the environment of the small base station, and easily affect the radiation area and the radiation quality of the signal. Meanwhile, the radiation roundness problem is not solved fundamentally in the above modes, so that the radiation roundness improvement effect is not obvious.

Disclosure of Invention

The application provides a broadband antenna of a small base station, which aims to solve the problem of poor radiation roundness of the existing broadband antenna.

The application provides a broadband antenna of a small base station, which comprises a metal carrier and at least one antenna unit arranged on the metal carrier; the antenna unit is arranged at the edge position of the metal carrier; wherein the antenna unit includes: the radiator, the circuit board and the current path branch;

the radiator is connected with the circuit board so as to be arranged on the metal carrier through the circuit board; the current path branch is connected with the radiator metal sheet structure and is parallel to the metal carrier; feeding current flows through the current path branch to form structural current, so that the direction of a feeding current distribution path on the radiator is opposite to the direction of ground current on one side, close to the center, of the metal carrier; and forming a compensating current path that cancels a reverse current on the radiator.

Optionally, the antenna unit further includes a feeding pin; the radiator is of a metal sheet structure; the radiator is connected with the circuit board through the feed pin and parallel to the metal carrier.

Optionally, the antenna unit further includes a ground pin; the circuit board is provided with a grounding layer, and the radiator is connected with the grounding layer on the circuit board through the grounding pin.

Optionally, the antenna unit includes two radiators and two current path branches; the two radiators and the two current path branches form a rectangular frame structure parallel to the metal carrier.

Optionally, the radiator is a rod-shaped radiation arm disposed on the metal carrier; one end of the radiator is connected with the metal carrier through the circuit board, and the other end of the radiator is vertically connected with the current path branch.

Optionally, the current path stub is of a U-shaped metal sheet structure, and an opening of the current path stub faces to the center of the metal carrier; the radiator is connected with the middle position of the bottom edge of the branch of the current path.

Optionally, the current path branch is of a hollow rectangular frame structure.

Optionally, the radiator and the current path stub are of an integrated structure.

Optionally, the metal carrier is a rectangular metal plate, and four antenna units are respectively arranged at four corners of the metal carrier.

Optionally, the circuit board is a PCB board which is attached to the edge of the metal carrier.

According to the technical scheme, the broadband antenna for the small base station comprises the antenna unit and the metal carrier, wherein the antenna unit is arranged at the edge of the metal carrier. Wherein, the antenna unit includes: radiator, circuit board and current path stub. The radiator is connected with the circuit board so as to be arranged on the metal carrier through the circuit board; the current path branch is of a structure connected with a radiator metal sheet and is parallel to the metal carrier; feeding current flows through the current path branch to form structural current, so that the direction of a feeding current distribution path on the radiator is opposite to the direction of ground current on one side, close to the center, of the metal carrier; and forming a compensating current path that cancels a reverse current on the radiator. This application improves radiation circularity through the mode of constructing antenna compensation radiation current, and simple structure, the stable performance, simple to operate solves the poor problem of radiation circularity of current wide band antenna.

Drawings

In order to more clearly explain the technical solution of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious to those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of a dipole;

fig. 2 is a schematic view of a current path structure when the radiator is disposed at a central position of the metal carrier;

fig. 3 is a radiation diagram of a radiation field in a horizontal direction when the radiator is disposed at a central position of the metal carrier;

fig. 4 is a schematic view of a current path structure when the radiator is disposed at an edge of the metal carrier;

fig. 5 is a radiation diagram of a radiation field in a horizontal direction when the radiator is disposed at an edge position of the metal carrier;

fig. 6 is a schematic structural diagram of a broadband antenna of a small base station according to the present application;

fig. 7 is a schematic structural diagram of an antenna unit according to the present application;

fig. 8 is a schematic structural diagram of a current path constructed when the radiator of the present application is disposed at a corner of a metal carrier;

fig. 9 is a schematic structural diagram of a current path constructed when the radiator is disposed at an edge of a metal carrier according to the present application;

FIG. 10 is a schematic diagram of the present application when reverse current is present;

FIG. 11 is a schematic structural diagram of a current path constructed when the relative bandwidth of the present application reaches 40% -50%;

FIG. 12 is a schematic diagram of a current path branch structure of the hollow rectangular frame structure of the present application;

FIG. 13 shows the current distribution of the antenna unit of the present application at 1.7 GHz;

FIG. 14 shows the current distribution of the antenna unit of the present application at 2.7 GHz;

fig. 15 shows the current distribution of the antenna unit of the present application at 3.6 GHz.

Detailed Description

Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following examples do not represent all embodiments consistent with the present application. But merely as exemplifications of systems and methods consistent with certain aspects of the application, as recited in the claims.

According to the technical scheme, the broadband antenna of the small base station can improve the radiation roundness of the whole antenna. In practice, the conventional omni-directional antenna usually places the antenna unit at the center of the metal carrier (reference ground), as shown in fig. 1. According to the mirror image principle, a dipole can be constructed, and the antenna radiation field can be obtained.

Wherein the directional pattern function:

it can be seen that the current distribution on the metal carrier is centrosymmetric, and the current directions on both sides of the radiator are opposite, so that far-field radiation can be cancelled out without radiation, as shown in fig. 2. Accordingly, the radiation pattern of the total radiation field in the horizontal direction is shown in fig. 3.

But for small base stations the radiator needs to be placed at the edge of the metal carrier, as there is not enough space to place the radiator, as shown in fig. 4. As the boundary condition on the reference ground changes, the current distribution is asymmetric, and a far-field horizontal directional pattern can be obtained through the radiation principle, as shown in fig. 5, that is, the radiation roundness is affected in a certain direction of the radiator, so that the directional pattern shows a deep concave point, and the roundness is deteriorated.

In order to improve the radiation roundness of the antenna, the application provides a broadband antenna of a small base station. Fig. 6 is a schematic structural diagram of a broadband antenna of a small base station according to the present application.

As shown in fig. 6, the small base station broadband antenna provided by the present application includes anantenna unit 1 and ametal carrier 2. Theantenna unit 1 is used for generating and receiving wireless electromagnetic waves to realize the transmission and reception of signals. Theantenna unit 1 can select a monopole antenna, a microstrip patch antenna, a Loop antenna, a PIFA antenna, a dipole antenna, etc. according to different practical application scenarios. Themetal carrier 2 is a metal plate structure, which can provide support and perform grounding process to serve as a reference ground for signal transmission.

In practical applications, a plurality ofantenna units 1 may be disposed on thesame metal carrier 2. Limited by the narrow installation space of the small base station, theantenna unit 1 is arranged at the edge position of themetal carrier 2. The plurality ofantenna elements 1 may be disposed on themetal carrier 2 in different arrangements, for example, in a uniform distribution along the edge of themetal carrier 2. Theantenna unit 1 may be disposed on themetal carrier 2 near the edge or near the corner according to different application scenarios. For example, in the scheme corresponding to fig. 6, the whole small base station antenna includes ametal carrier 2 and fourantenna elements 1. Themetal carrier 2 is a rectangular metal plate, and fourantenna units 1 are respectively arranged at four corners of themetal carrier 2. The arrangement of a plurality ofantenna elements 1 on ametal carrier 2 can improve the signal transmission rate of the antenna in the radiation direction.

Since in the technical solution provided in the present application, theantenna unit 1 is also disposed at the edge of themetal carrier 2, theantenna unit 1 is also affected by the boundary condition on the reference ground, which results in an asymmetric current distribution on theantenna unit 1 and affects the signal radiation roundness.

In order to improve the signal radiation roundness of theantenna unit 1, in the present application, as shown in fig. 7, theantenna unit 1 includes: aradiator 12, acircuit board 14, and current path stubs 15. Wherein theradiator 12 is connected to thecircuit board 14 to be disposed on themetal carrier 2 through thecircuit board 14. In practical applications, theradiator 12 may be configured with different element structures according to the specific antenna type of theantenna unit 1. For example, when theantenna unit 1 is a monopole antenna, theradiator 12 has a rectangular metal plate structure. A signal processing module may be disposed on or external to thecircuit board 14 to feed theradiator 12 so that theradiator 12 generates a specific form of electromagnetic signal.

Further, theCircuit Board 14 is a PCB (Printed Circuit Board) attached to the edge of themetal carrier 2. The PCB has grounding and feeding functions.

Thecurrent path branch 15 is connected with theradiator 12 and is of a metal sheet structure, and thecurrent path branch 15 is parallel to themetal carrier 2; feeding current flows through the currentpath branch section 15 to form a structural current, so that the direction of a feeding current distribution path on theradiator 12 is opposite to the direction of ground current on one side, close to the center, of themetal carrier 2; and forming a compensating current path that cancels the reverse current on theradiator 12. In the technical scheme provided by the application, the equivalent current can be constructed on one side close to the edge through thecurrent path branch 15, so that the current transmitted into theradiator 12 keeps the same boundary condition in all directions, and the radiation roundness is improved.

It can be seen that the antenna radiation current is constructed by thecurrent path branch 15, so that the same ground current distribution as that of theradiator 12 at the center of themetal carrier 2 is realized, and the radiation roundness is improved.

In practical applications, in order to obtain better roundness of signals in the horizontal direction, it is necessary to construct a similar boundary condition to the metal carrier in fig. 2 on themetal carrier 2 near theradiator 12, as shown in fig. 8, the antenna is placed at a corner of the reference ground, and according to the mirror image principle, the horizontal radiation roundness can be improved by the same horizontal current flowing direction of the radiator of the antenna and the current flowing direction of the structure.

Similarly, if theantenna radiator 12 is placed at the edge of themetal carrier 2, it is necessary to configure the radiation current direction as shown in fig. 9, which can improve the horizontal radiation roundness of the antenna well. It can be seen that, in some embodiments of the present application, theradiator 12 is a rod-shaped radiating arm disposed on themetal carrier 2; one end of theradiator 12 is connected to themetal carrier 2 via acircuit board 14, and the other end is connected vertically to acurrent path stub 15.

However, as the working frequency band of the antenna is wider and wider, when the relative bandwidth reaches about 40% -50%, the current distribution in the high frequency band may be in a reverse direction, as shown in fig. 10, which may cause the roundness at the high frequency to be deteriorated, and a current path needs to be added, so that the current flow at the high frequency does not flow in a required direction, and the flow direction of the added current path is perpendicular to the required current flow direction, so as not to affect the overall radiation direction, and the horizontal radiation direction still maintains a better roundness, and at this time, the working wavelength of the antenna at the high frequency is 1/2 wavelengths.

That is, as shown in fig. 11, in some embodiments of the present application, thecurrent path branch 15 is a U-shaped metal sheet structure, and the opening of thecurrent path branch 15 faces the center of themetal carrier 2; theradiator 12 is connected to the middle of the bottom edge of thecurrent path stub 15.

When the relative bandwidth reaches more than 50%, theradiator 12 in fig. 11 also generates reverse current at high frequency, which affects the radiation roundness of high frequency, so that it is also necessary to increase the current path so that no reverse current occurs. As shown in fig. 12, thecurrent path branch 15 may be a hollow rectangular frame structure, so that a compensation current path is formed in the rectangular frame, and a reverse current does not occur in a required current direction, and the current is a vertical current, so that overall radiation is not affected, and a horizontal radiation direction can still maintain a good roundness, where an operating wavelength of the antenna at a high frequency is one wavelength.

According to the technical scheme, in order to obtain a wide band or an ultra-wideband antenna with better roundness in the horizontal radiation direction, the currentpath branch section 15 is arranged, so that the current distribution is similar in the whole bandwidth. Moreover, if a reverse current occurs in a required current flow direction, the reverse current can be eliminated through the addedcurrent branches 15, and the antenna can be kept to have good horizontal radiation roundness in the whole frequency band, as shown in fig. 13, 14 and 15, the current distribution in the broadband is kept consistent, and the good horizontal radiation roundness can be obtained.

In some embodiments of the present application, in order to cancel the reverse current and enhance the stability of the antenna as a whole, theradiator 12 and thecurrent path branch 15 are of an integral structure. Furthermore, theantenna unit 1 further comprises afeed pin 13. Thefeed pin 13 is used to feed theradiator 12 so that theradiator 12 generates electromagnetic radiation. Theradiator 12 is a metal sheet structure, i.e., a monopole antenna is formed by the metal sheet structure. Theradiator 12 is connected to thecircuit board 14 through thefeeding pin 13, and the electrical signal on thecircuit board 14 is transmitted to theradiator 12 in a direct feeding manner, so that theradiator 12 generates a transmission or reception electromagnetic signal.

Since the compensation current path generated on thecurrent path branch 15 needs to be perpendicular to the required current flow direction (i.e. the direction of the feed pin 13), thecurrent path branch 15 needs to be parallel to themetal carrier 2, as well as theradiator 12 of the corresponding integral structure.

Further, theantenna unit 1 further includes aground pin 11; thecircuit board 14 is provided with a ground plane, and theradiator 12 is connected to the ground plane on thecircuit board 14 through theground pin 11. For example, theantenna unit 1 includes tworadiators 12 and twocurrent path branches 15; the tworadiators 12 and the twocurrent path branches 15 form a rectangular frame structure parallel to themetal carrier 2. As shown in fig. 6 and 7, the top of theantenna unit 1 may be a hollow rectangular metal sheet, and thecurrent path branch 15 and theradiator 12 are four sides of a rectangular frame, respectively, in practical applications, thecircuit board 14 feeds power to theradiator 12 through thefeeding pin 13, and a current formed by the feeding is affected by boundary conditions of themetal carrier 2, so that a compensation current path is formed on theradiator 12 and thecurrent path branch 15, a reverse current is cancelled, and radiation roundness of the antenna is maintained.

In practical application, the radiation roundness of the signal can be obviously improved by theantenna unit 1, and as shown in fig. 12, 11 and 14, the current distribution of theantenna unit 1 in the signals of 1.7GHz, 2.7GHz and 3.6GHz can be kept consistent, so that better horizontal radiation roundness can be obtained. Through actual test experiments, under different antenna signals. Theantenna unit 1 provided by the application has better roundness in the whole frequency band, wherein the roundness worst value is-5.31 dB, and the requirement of a small base station on radiation roundness is also met.

According to the technical scheme, the broadband antenna for the small base station comprises theantenna unit 1 and themetal carrier 2, wherein theantenna unit 1 is arranged at the edge of themetal carrier 2. Wherein,antenna unit 1 includes: aradiator 12, acircuit board 14, and current path stubs 15. Theradiator 12 is connected to thecircuit board 14 to be disposed on themetal carrier 2 through thecircuit board 14; thecurrent path branch 15 is connected with the metal sheet structure of theradiator 12, and thecurrent path branch 15 is parallel to themetal carrier 2; feeding current flows through the currentpath branch section 15 to form a structural current, so that the direction of a feeding current distribution path on theradiator 12 is opposite to the direction of ground current on one side, close to the center, of themetal carrier 2; and forming a compensating current path that cancels the reverse current on theradiator 12. This application improves radiation circularity through the mode of constructing antenna compensation radiation current, and simple structure, the stable performance, simple to operate solves the poor problem of radiation circularity of current wide band antenna.

The embodiments provided in the present application are only a few examples of the general concept of the present application, and do not limit the scope of the present application. Any other embodiments extended according to the scheme of the present application without inventive efforts will be within the scope of protection of the present application for a person skilled in the art.

Claims (10)

Translated fromChinese

1.一种小基站宽频天线，包括金属载体(2)和设置在所述金属载体(2)上的至少一个天线单元(1)；所述天线单元(1)设置在所述金属载体(2)的边缘位置；其特征在于，所述天线单元(1)包括：辐射体(12)、电路板(14)以及电流路径枝节(15)；1. A small base station broadband antenna, comprising a metal carrier (2) and at least one antenna unit (1) arranged on the metal carrier (2); the antenna unit (1) is arranged on the metal carrier (2) ); characterized in that the antenna unit (1) comprises: a radiator (12), a circuit board (14) and a current path branch (15);所述辐射体(12)连接所述电路板(14)，以通过所述电路板(14)设置在所述金属载体(2)上；所述电流路径枝节(15)为连接所述辐射体(12)金属片结构，所述电流路径枝节(15)平行于所述金属载体(2)；所述电流路径枝节(15)上流通馈电电流形成构造电流，使所述辐射体(12)上馈电电流分布路径与所述金属载体(2)上靠近中心一侧的地电流方向相反；以及形成抵消所述辐射体(12)上的反向电流的补偿电流路径。The radiator (12) is connected to the circuit board (14), so as to be arranged on the metal carrier (2) through the circuit board (14); the current path branch (15) is for connecting the radiator (12) A metal sheet structure, the current path branch (15) is parallel to the metal carrier (2); a feed current flows on the current path branch (15) to form a structural current, so that the radiator (12) The upper feeding current distribution path is opposite to the ground current on the side close to the center on the metal carrier (2); and a compensation current path is formed to cancel the reverse current on the radiator (12).2.根据权利要求1所述的小基站宽频天线，其特征在于，所述天线单元(1)还包括馈电脚(13)；所述辐射体(12)为金属片结构；所述辐射体(12)通过所述馈电脚(13)连接所述电路板(14)，所述辐射体(12)平行于所述金属载体(2)。2 . The small base station broadband antenna according to claim 1 , wherein the antenna unit ( 1 ) further comprises a feeding pin ( 13 ); the radiator ( 12 ) is a metal sheet structure; the radiator (12) The circuit board (14) is connected through the feeding pin (13), and the radiator (12) is parallel to the metal carrier (2).3.根据权利要求2所述的小基站宽频天线，其特征在于，所述天线单元(1)还包括接地脚(11)；所述电路板(14)上设有接地层，所述辐射体(12)通过所述接地脚(11)连接所述电路板(14)上的接地层。3. The small base station broadband antenna according to claim 2, wherein the antenna unit (1) further comprises a grounding pin (11); a grounding layer is provided on the circuit board (14), and the radiator (12) The grounding layer on the circuit board (14) is connected through the grounding pin (11).4.根据权利要求2所述的小基站宽频天线，其特征在于，所述天线单元(1)包括两个所述辐射体(12)和两个电流路径枝节(15)；两个所述辐射体(12)和两个电流路径枝节(15)组成平行于所述金属载体(2)的矩形框结构。4. The small base station broadband antenna according to claim 2, wherein the antenna unit (1) comprises two radiators (12) and two current path branches (15); two said radiators The body (12) and the two current path branches (15) form a rectangular frame structure parallel to the metal carrier (2).5.根据权利要求1所述的小基站宽频天线，其特征在于，所述辐射体(12)为设置在所述金属载体(2)上的杆状辐射臂；所述辐射体(12)的一端通过所述电路板(14)连接所述金属载体(2)，另一端垂直连接所述电流路径枝节(15)。5. The small base station broadband antenna according to claim 1, wherein the radiator (12) is a rod-shaped radiating arm arranged on the metal carrier (2); One end is connected to the metal carrier (2) through the circuit board (14), and the other end is vertically connected to the current path branch (15).6.根据权利要求5所述的小基站宽频天线，其特征在于，所述电流路径枝节(15)为U形金属片结构，所述电流路径枝节(15)的开口朝向所述金属载体(2)的中心；所述辐射体(12)连接所述电流路径枝节(15)底边的中部位置。6. The small base station broadband antenna according to claim 5, wherein the current path branch (15) is a U-shaped metal sheet structure, and the opening of the current path branch (15) faces the metal carrier (2). ); the radiator (12) is connected to the middle position of the bottom edge of the current path branch (15).7.根据权利要求5所述的小基站宽频天线，其特征在于，所述电流路径枝节(15)为中空矩形框结构。7. The small base station broadband antenna according to claim 5, wherein the current path branch (15) is a hollow rectangular frame structure.8.根据权利要求1所述的小基站宽频天线，其特征在于，所述辐射体(12)和所述电流路径枝节(15)为一体式结构。8. The small base station broadband antenna according to claim 1, characterized in that, the radiator (12) and the current path branch (15) have an integrated structure.9.根据权利要求1所述的小基站宽频天线，其特征在于，所述金属载体(2)为矩形金属板，所述金属载体(2)的四角位置分别设有四个所述天线单元(1)。9 . The small base station broadband antenna according to claim 1 , wherein the metal carrier ( 2 ) is a rectangular metal plate, and four antenna units ( 1).10.根据权利要求1所述的小基站宽频天线，其特征在于，所述电路板(14)为贴合设置在所述金属载体(2)边缘位置上的PCB板。10 . The small base station broadband antenna according to claim 1 , wherein the circuit board ( 14 ) is a PCB board that is attached to the edge of the metal carrier ( 2 ). 11 .

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