CN112186341B

CN112186341B - Base station antenna, low-frequency radiation unit and radiation arm

Info

Publication number: CN112186341B
Application number: CN202011050717.9A
Authority: CN
Inventors: 彭敏生; 姜维维; 薛锋章
Original assignee: South China University of Technology SCUT; Comba Telecom Technology Guangzhou Ltd; Jingxin RF Technology Guangzhou Co ltd
Current assignee: South China University of Technology SCUT; Comba Telecom Technology Guangzhou Ltd; Jingxin RF Technology Guangzhou Co ltd
Priority date: 2020-09-29
Filing date: 2020-09-29
Publication date: 2021-12-28
Anticipated expiration: 2040-09-29
Also published as: CN112186341A

Abstract

The invention discloses a base station antenna, a low-frequency radiation unit and a radiation arm, wherein the radiation arm comprises a first substrate, a radiation layer, a first filtering branch section and a second filtering branch section; the first substrate comprises a first surface and a second surface opposite to the first surface, and the radiation layer is arranged on the first surface; the first filtering branch section is arranged on the first surface and is electrically connected with the radiation layer; the second filtering branch node is arranged on the second surface and is electrically connected with the first filtering branch node. The radiation arm has better anti-interference capability. The low-frequency radiation unit adopts the radiation arm, so that the coupling influence on the high-frequency radiation unit can be reduced, high-frequency harmonic waves are inhibited, and the radiation performance is favorably improved. The base station antenna has better radiation performance by adopting the low-frequency radiation unit.

Description

Base station antenna, low-frequency radiation unit and radiation arm

Technical Field

The invention relates to the technical field of base stations, in particular to a base station antenna, a low-frequency radiation unit and a radiation arm.

Background

With the development of wireless technology, the introduction of new communication spectrum and communication system, a multi-system shared base station antenna supporting more frequency bands and more systems gradually becomes a mainstream product required by operators.

With the full arrival of the fifth generation communication system, several communication systems, 2G, 3G, 4G and 5G, will coexist for a long time, and there are many different communication standards, which requires more base stations to provide services for the communication system. Meanwhile, with the increasing concern of people on the installation and environment beautification of base station antennas and the worry of people on radiation and the conflict of the original base station position, the site selection of the base station antennas is more and more difficult, and the multi-frequency base station antennas gradually become the mainstream.

Disclosure of Invention

In view of the above, it is desirable to provide a base station antenna, a low frequency radiating element and a radiating arm; the radiation arm can reduce the coupling influence on the radiation unit in a high-frequency band. The low-frequency radiation unit adopts the radiation arm to inhibit high-frequency harmonic waves, and is favorable for improving the radiation performance of the high-frequency and low-frequency nested antenna. The base station antenna adopts the low-frequency radiation unit, so that the high-frequency radiation unit can be better integrated, and the directional diagram of the high-frequency radiation unit is favorably improved.

The technical scheme is as follows:

in one aspect, the present invention provides a radiation arm, including a first substrate, a radiation layer, and a first filter stub; the first substrate comprises a first surface and a second surface opposite to the first surface, and the radiation layer is arranged on the first surface; the first filtering branch node is arranged on the second surface and is electrically connected with the radiation layer.

The radiating arm integrates the radiating layer by utilizing the substrate, so that impedance matching is easy to realize, and the radiating layer is easy to modify, so that the radiating arm meets the requirements of the base station antenna. Meanwhile, the first filtering branch section is arranged, so that external high-frequency harmonic interference can be better resisted, and the influence of the radiation arm on the high-frequency radiation unit is optimized. And through setting up first filtering branch festival in the second face, be favorable to integrated filtering branch festival in finite space, be convenient for adjust filtering efficiency, further promote the interference killing feature of radiation arm.

The technical solution is further explained below:

in one embodiment, the number of the first filtering branches is at least two, and the first filtering branches are arranged on the second surface at intervals.

In one embodiment, the first filter stub is a winding structure; or/and the second filter stub is of a sheet structure.

In one embodiment, the first filter stub is electrically connected to the radiation layer through a metal via, and the length of the first filter stub is 1/4 λ, where λ is a wavelength of the interference frequency in the first substrate.

In another aspect, the present invention provides a low-frequency radiating element, which includes four radiating arms in any of the above embodiments, and the four radiating arms are orthogonally arranged to form two pairs of dipoles.

Whether the design initial stage of the low-frequency radiation unit meets the requirement of the radiation performance of the base station antenna or not needs to be repeatedly debugged and modified in the early stage; because the low-frequency radiating unit adopts the radiating arm, the radiating layer is integrated by utilizing the substrate, the modification of the radiating layer is easy to carry out, namely, part of the radiating layer can be removed on the substrate or the metal layer is welded to increase the radiating layer to change the performance, so that the low-frequency radiating unit is produced in large scale after meeting the requirement of the base station antenna. Meanwhile, the first filtering branch section is arranged, so that the coupling influence on the high-frequency radiation unit can be reduced, high-frequency harmonic waves are restrained, and the radiation performance of the high-frequency and low-frequency nested antenna is optimized. And through setting up first filtering branch festival in the second face, be favorable to integrated filtering branch festival in finite space, be convenient for adjust the filtering performance of filtering branch festival according to actual conditions, be favorable to further promoting low frequency radiating element's interference killing feature.

The technical solution is further explained below:

in one embodiment, the low-frequency radiating element further comprises a balun, and the two pairs of dipoles are respectively fed through the balun.

In one embodiment, the balun comprises two second substrates which are orthogonally arranged in a cross manner, the second substrates are fixedly connected with the first substrate, each second substrate comprises a third surface, and the third surface is provided with a second filter branch which is coupled with a pair of dipoles for feeding.

In one embodiment, the low frequency radiating element further comprises a ground plate, the ground plate is provided with a transmission line electrically connected with the second filter leg, and the transmission line is provided with a connection point.

In one embodiment, the second substrate further includes a fourth surface disposed opposite to the third surface, the fourth surface is provided with a ground line, the ground plate is provided with a ground layer, and the dipole is connected to the ground layer through the ground line.

In another aspect, the present invention provides a base station antenna, including the low frequency radiating element in any of the above embodiments.

The base station antenna adopts the low-frequency radiation unit, so that the high-frequency radiation unit can be better integrated, and the directional diagram of the high-frequency radiation unit is favorably improved. In the process of developing the base station antenna, the low-frequency radiation unit is beneficial to reducing the research and development cost and improving the research and development efficiency.

Drawings

Fig. 1 is a schematic structural diagram of a low-frequency radiating element shown in an embodiment;

fig. 2 is a schematic bottom view of the low frequency radiating unit shown in fig. 1;

fig. 3 is a schematic structural diagram of a low-frequency radiating element shown in another embodiment;

FIG. 4 is a schematic diagram of the mating of the balun and the grounding plate in one embodiment;

fig. 5 is an exploded view of the balun shown in fig. 4.

Description of reference numerals:

10. a dipole; 100. a radiation arm; 110. a first substrate; 112. a first side; 114. a second face; 120. a radiation layer; 130. a first filtering stub; 20. a balun; 210. a second substrate; 212. a third surface; 214. a fourth surface; 216. a card slot; 220. a second filtering stub; 230. a ground line; 30. a ground plate; 310. a transmission line; 312. and connecting points.

Brief description of the drawingsthe accompanying drawings, which form a part hereof, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention, and together with the description, serve to explain the invention and not to limit the invention.

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and the detailed description. It should be understood that the detailed description and specific examples, while indicating the scope of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The radiation unit, as the minimum radiation element of the antenna, is an important component of the base station antenna. In the process of developing a new base station antenna, a new radiating element needs to be designed, but whether the designed radiating element meets the requirement or not needs to be actually verified to pass the requirement. If the requirement is not met or not met, the structure or the size of the radiation arm needs to be adjusted at the moment, but in the traditional mode, the radiation unit is manufactured in an integrated forming mode, the radiation arm is modified at the moment, the size of the mold needs to be adjusted again, even the mold can be opened again, the research and development period is too long to catch up with the progress, the research and development cost is also improved, and the waste of the mold is caused.

As shown in fig. 1 and fig. 3, in an embodiment, a low frequency radiating unit is provided, which includes four radiating arms 100, and the four radiating arms 100 are orthogonally arranged to form two pairs of dipoles 10.

As shown in fig. 1 and fig. 2, the radiation arm 100 includes a first substrate 110, a radiation layer 120, and a first filter stub 130; the first substrate 110 includes a first surface 112 and a second surface 114 disposed opposite to the first surface 112, and the radiation layer 120 is disposed on the first surface 112; the first filtering branch 130 is disposed on the second surface 114, and the first filtering branch 130 is electrically connected to the radiation layer 120. In this way, the radiation arm 100 integrates the radiation layer 120 with the substrate, so that impedance matching is easily achieved, and modification of the radiation layer 120 is easily performed, so that the radiation arm 100 meets the requirements of the base station antenna. Meanwhile, the first filter stub 130 can better resist external high-frequency harmonic interference, and the electrical performance and the radiation performance of the radiation arm 100 are optimized. And by arranging the first filtering branch section 130 on the second surface 114, the filtering branch section can be integrated in a limited space, so that the filtering efficiency can be adjusted conveniently, and the anti-interference capability of the radiation arm 100 can be further improved.

Whether the design initial stage of the low-frequency radiation unit meets the requirement of the radiation performance of the base station antenna or not needs to be repeatedly debugged and modified in the early stage; because the low-frequency radiating unit adopts the radiating arm 100, the radiating layer 120 is integrated by using the substrate, the modification of the radiating layer 120 is easy, namely, part of the radiating layer 120 on the substrate can be removed or a metal layer is welded to increase the radiating layer 120 to change the performance, so that the low-frequency radiating unit is produced in a large scale after meeting the requirements of the base station antenna, and the low-frequency radiating unit is beneficial to improving the research and development efficiency and reducing the research and development cost. Meanwhile, the first filtering branch 130 is arranged, so that the coupling influence on the high-frequency radiation unit can be reduced, high-frequency harmonic waves can be suppressed, and the radiation performance of the high-frequency and low-frequency nested antenna can be optimized. And by arranging the first filtering branch section 130 on the second surface 114, the filtering branch section can be integrated in a limited space, the filtering performance of the filtering branch section can be adjusted conveniently according to actual conditions, and the anti-interference capability of the low-frequency radiation unit can be further improved.

The dielectric constant of the first substrate 110 may be selected as needed, and the material thereof may be selected according to the prior art.

Furthermore, the four radiating arms 100 may be manufactured separately and then assembled together; the low-frequency radiating element can also be manufactured on one substrate at one time by utilizing the printed circuit board technology. The selection can be made according to the performance requirement of the low-frequency radiating unit.

It should be noted that the "first filter stub 130" and the "radiation layer 120" may be electrically connected through a metal via or the like in the prior art.

Based on the above embodiments, as shown in fig. 2, in an embodiment, at least two first filtering branches 130 are disposed on the second surface at intervals. Therefore, a better filtering effect can be obtained, and the first filtering branch sections 130 can be flexibly arranged according to the performance requirements of the radiation units. While the radiation layer 120 and the first filter stub 130 can be obtained by a developing technique.

In an embodiment based on any of the above embodiments, the first filter stub 130 has a winding structure. In this way, by arranging the first filtering branch 130 on the second surface 114 in a winding manner, a sufficiently long length can be obtained in a smaller area to meet the requirement of wave suppression, the area of the low-frequency radiating unit can be reduced, and the size of the base station antenna can be further reduced.

Or in another embodiment, as shown in fig. 2, the first filter stub 130 has a plate-like structure. Thus, the first filtering branch section 130 is disposed on the second surface 114 and has a sheet structure, so as to be used as a shielding layer of the radiation layer 120, and also has a filtering effect, thereby being beneficial to further improving the anti-interference capability of the low-frequency radiation unit and obtaining better working performance.

Or in another embodiment, at least two first filter branches 130 are combined, wherein one first filter branch 130 is in a winding structure, and one first filter branch 130 is in a sheet structure. Therefore, the required filtering effect can be obtained by utilizing the filtering branches with different structures so as to meet the performance requirements of different low-frequency radiating units.

It should be noted that the "coil structure" includes a square coil shape, a circular coil shape, an elliptical coil shape, or other polygonal coil shapes.

Further, the "sheet-like structure" has a polygonal shape, a circular shape, an oval shape, or the like on the second face 114.

In addition to any of the above embodiments, in an embodiment, the length of the first filter stub 130 is 1/4 λ, where λ is a wavelength of the interference frequency in the first substrate 110. So, reduce this low frequency radiating element greatly and to this high frequency radiating element's coupling influence, the nested antenna pattern of high low frequency that has used this low frequency radiating element can effectively be improved for the interference killing feature of antenna is strong, is applied to multifrequency base station antenna, is favorable to promoting the radiation performance of multifrequency base station antenna.

On the basis of any of the above embodiments, as shown in fig. 3, in an embodiment, the low-frequency radiating element further includes a balun 20, and the two pairs of dipoles 10 are respectively fed through the balun 20. Therefore, the low-frequency radiating unit can be fed and supported by the balun 20, and is favorable for nested application in antennas of different frequency bands.

Further, as shown in fig. 3 to fig. 5, in an embodiment, the balun 20 includes two second substrates 210 orthogonally crossed, the second substrates 210 are fixedly connected to the first substrate 110, the second substrates 210 include a third surface 212, the third surface 212 is provided with a second filter branch 220, and the second filter branch 220 is coupled to the pair of dipoles 10 for feeding. Thus, the second substrate 210 is used to integrate the second filtering branch 220, and the second filtering branch 220 and the corresponding pair of dipoles 10 are used for coupling and feeding, so that the number of welding points can be reduced, errors caused by uncontrollable volume of a welding layer can be reduced, the consistency of the radiation performance of the low-frequency radiation unit can be ensured, and intermodulation can be reduced. Meanwhile, the mutual coupling problem of the multi-band multi-system antenna caused by the fact that the distance between the high-frequency radiating unit and the low-frequency radiating unit is relatively close can be weakened through the arrangement of the second filtering branch section, and the design difficulty of the multi-band multi-system antenna is reduced.

Alternatively, the second filter stub 220 may be a microstrip line. Therefore, the anti-interference performance of the low-frequency radiation unit can be further improved.

Optionally, the second filter leg 220 is in the shape of an inverted "L".

Of course, the second filter stub 220 can be obtained on the second substrate 210 by using the printed wiring board technology, and then the two second substrates 210 are orthogonally cross-assembled into the balun 20.

Specifically, the second substrate 210 is provided with a card slot 216. And the two second substrates 210 can be assembled together by the snap-fit grooves 216.

The dielectric constant of the second substrate 210 may be selected according to the needs, and the material thereof may be selected according to the prior art.

In addition to any of the above embodiments of the second substrate 210, as shown in fig. 4 and 5, in an embodiment, the second substrate 210 further includes a fourth surface 214 disposed opposite to the third surface 212, the fourth surface 214 is provided with a ground line 230, the ground plane is provided with a ground layer, and the dipole is connected to the ground layer through the ground line. In this way, the ground line 230 is provided in the balun 20, thereby grounding the low-frequency radiating element.

It can be understood that the radiation arm 100 and the balun 20 can be manufactured by using printed circuit board technology, so that impedance matching is easier to achieve, and it is beneficial to reduce the design difficulty of a new antenna and reduce the research and development cost of the new antenna.

Optionally, the ground line 230 is a microstrip line. Therefore, the impedance of the low-frequency radiation unit is easier to adjust, and the intermodulation difficulty of the base station antenna is favorably reduced.

On the basis of any of the above-mentioned embodiments of the second filter stub 220, as shown in fig. 3 and fig. 4, in an embodiment, the low frequency radiating unit further includes a ground plate 30, the ground plate 30 is provided with a transmission line 310 electrically connected to the second filter stub 220, and the transmission line 310 is provided with a connection point 312. Therefore, the shielding effect can be better formed by utilizing the grounding plate 30, and the anti-interference capability of the low-frequency radiation unit is further improved. Meanwhile, the connection point 312 of the transmission line 310 is used to integrate other elements, which is beneficial to improving the assembly efficiency of the antenna. If the coaxial cable is electrically connected and fixed through the connection point 312, the coaxial cable is conveniently integrated on the low-frequency radiating unit, so that the low-frequency radiating unit is conveniently fed.

Meanwhile, it can be understood that each low-frequency radiating unit is coupled to feed and ground through the ground line 230 and the second filtering branch 220, and is combined with the first filtering branch 130, which is beneficial to greatly improving the intermodulation stability of the base station antenna system, when the low-frequency radiating unit is combined with other low-frequency radiating units or embedded into a reflecting plate to form a base station antenna, the problem of mutual coupling is solved without separately adding a filtering branch in the main circuit network of the phase shifter, and the problem that the filtering branch cannot be separately added in the existing low-frequency radiating unit is solved. Moreover, the whole feed network is more compact, the number of feed cables is reduced, and the whole weight of the base station antenna is reduced; and this low frequency radiation unit's interference killing feature is strong for this low frequency radiation unit interval can be littleer on the reflecting plate, and then makes the base station antenna compacter, is favorable to dwindling the base station antenna volume.

Furthermore, the installation space of the antenna is smaller and smaller at present, the technical scheme of the low-frequency radiating unit is beneficial to reducing the weight and the volume of the antenna, and has great significance for completing or accelerating the construction of 4G or/and 5G antennas. The reduction of weight inevitably brings convenience to antenna installation, reduces the burden on an antenna installation area, and particularly reduces the burden on an iron tower. And the volume is reduced, so that the 4G or/and 5G antenna can be installed in a limited space, the coverage of the 4G or/and 5G antenna in the area is realized, the antenna of a high-frequency band is not required to be adjusted or dismantled, and the debugging time is greatly saved

In an embodiment, a base station antenna is provided, which includes the low frequency radiating element in any of the above embodiments.

Meanwhile, the low-frequency radiation unit is beneficial to reducing the whole weight and the size of the base station antenna, and has great significance for completing or accelerating the construction of 4G or/and 5G antennas. Because of the reduction of weight, the convenience of antenna installation is inevitably brought, and the burden on an antenna installation area, especially the burden on an iron tower, is reduced. And the volume is reduced, so that the 4G or/and 5G antenna can be installed in a limited space, the coverage of the 4G or/and 5G antenna in the area is realized, the antenna in a high-frequency band is not required to be adjusted or dismantled, and the debugging time is greatly saved.

The "certain body" and the "certain portion" may be a part corresponding to the "member", that is, the "certain body" and the "certain portion" may be integrally formed with the other part of the "member"; the "part" can be made separately from the "other part" and then combined with the "other part" into a whole. The expressions "a certain body" and "a certain part" in the present invention are only one embodiment, and are not intended to limit the scope of the present invention for reading convenience, and the present invention should be construed as equivalent technical solutions if the features and the effects described above are included.

It should be noted that, the components included in the "unit", "assembly", "mechanism" and "device" of the present invention can also be flexibly combined, i.e., can be produced in a modularized manner according to actual needs, so as to facilitate the modularized assembly. The division of the above components into the present invention is only one embodiment, which is convenient for reading and is not a limitation to the protection scope of the present invention, and the equivalent technical solutions of the present invention should be understood as if they include the above components and have the same function.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to," "disposed on," "secured to," or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. Further, when one element is considered as "fixed transmission connection" with another element, the two elements may be fixed in a detachable connection manner or in an undetachable connection manner, and power transmission can be achieved, such as sleeving, clamping, integrally-formed fixing, welding and the like, which can be achieved in the prior art, and is not cumbersome. When an element is perpendicular or nearly perpendicular to another element, it is desirable that the two elements are perpendicular, but some vertical error may exist due to manufacturing and assembly effects. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A low frequency radiating element comprising a radiating arm, said radiating arm comprising:

the first substrate comprises a first surface and a second surface opposite to the first surface;

the radiation layer is in a strip shape and is arranged on the first surface; and

the first filtering branch section is arranged on the second surface along the direction from one end of the radiation layer to the other end of the radiation layer, and the first filtering branch section is electrically connected with the radiation layer; the number of the radiation arms is four, and the four radiation arms are mutually orthogonally arranged to form two pairs of dipoles;

the balun comprises two second substrates which are orthogonally arranged in a crossed manner, the second substrates are fixedly connected with the first substrate, each second substrate comprises a third surface, a second filtering branch is arranged on each third surface, and the second filtering branches are coupled with the pair of dipoles for feeding;

and the ground plate is provided with a transmission line electrically connected with the second filtering branch section, and the transmission line is provided with a connection point.

2. The low frequency radiating element of claim 1, wherein the first filtering branches are at least two and spaced apart from each other on the second surface.

3. The low frequency radiating element of claim 1, wherein the first filter stub is a coiled structure; or/and the first filtering branch section is of a sheet structure.

4. The low frequency radiating element of claim 3, wherein the coiled structure comprises a square coil shape, a circular coil shape, or an elliptical coil shape.

5. The low frequency radiating element of claim 1, wherein the first filter stub is electrically connected to the radiating layer by a metal via.

6. The low frequency radiating element of claim 1, wherein the first filter stub has a length of 1/4 λ, λ being a wavelength of an interference frequency in the first substrate.

7. The low frequency radiating element of claim 1, wherein the second filter stub is a microstrip line; the second filtering branch section is in an inverted L shape.

8. The low-frequency radiating element according to claim 1, wherein a clamping groove is formed on the second substrate; the two second substrates are assembled together through the clamping groove in a buckling mode.

9. The low frequency radiating element of claim 1, wherein the second substrate further comprises a fourth surface disposed opposite to the third surface, the fourth surface is provided with a ground line, the ground plane is provided with a ground layer, and the dipole is connected to the ground layer through the ground line.

10. A base station antenna comprising a low frequency radiating element according to any one of claims 5 to 9.