阅读说明：本技术 偶极臂 (Dipole arm ) 是由 胡贯朋 陆友峰 王黎明 于 2018-07-23 设计创作，主要内容包括：本发明公开了一种用于蜂窝基站天线的低频带辐射器的偶极臂,其包括：中心轴；和至少一个筒体,所述筒体具有第一端、第二端和位于第一端与第二端之间的周壁,第一端具有端壁,所述端壁上设有接合部,所述筒体通过接合部与中心轴接合并且围绕中心轴设置。本公开的偶极臂适于大批量自动化生产,质量稳定性高,并且能够实现更好的无源互调变形性能。(The invention discloses a dipole arm for a low-band radiator of a cellular base station antenna, comprising: a central shaft; and at least one cylinder having a first end, a second end, and a peripheral wall between the first end and the second end, the first end having an end wall with a joint provided thereon, the cylinder being engaged with and disposed around the central axis by the joint. The dipole arm is suitable for large-batch automatic production, high in quality stability and capable of achieving better passive intermodulation distortion performance.)

1. A dipole arm for a low-band radiator of a cellular base station antenna, said dipole arm comprising:

a central shaft; and

at least one cylinder having a first end, a second end, and a circumferential wall therebetween, the first end having an end wall with an engagement portion provided thereon, the cylinder being engaged with and disposed about the central axis by the engagement portion.

2. The dipole arm of claim 1 wherein the second end is open to the outside.

3. The dipole arm of claim 1 wherein the at least one cylinder is circular or elliptical in cross-section.

4. The dipole arm of claim 1 wherein the at least one cylinder comprises a metallic material.

5. The dipole arm of claim 1 wherein the at least one cylinder comprises a plurality of cylinders axially spaced along the central axis.

6. The dipole arm of claim 5 wherein the plurality of cylinders have the same structure or different structures.

7. The dipole arm of claim 5 wherein the plurality of cylinders have the same diameter or different diameters and have the same axial length or different axial lengths.

8. The dipole arm of claim 5 wherein the plurality of cylinders have successively increasing axial lengths along the central axis.

9. The dipole arm of claim 5 wherein the second ends of the plurality of cylinders are open outwardly in the same direction.

10. The dipole arm of claim 1 wherein the at least one cylinder is mechanically and electrically coupled to the central shaft by a joint.

Technical Field

The present disclosure relates generally to cellular base station antennas and, more particularly, to dipole arms for low-band radiators of cellular base station antennas.

Background

Cellular communication systems connect a user's cellular device to a wireless network through a base station. The base station includes a baseband device, a radio, and an antenna for bi-directional radio frequency communication with the users. The base station antennas may be mounted on towers or other elevated structures and produce outward beams of radiation to serve respective geographic areas.

A multi-band base station antenna is a base station antenna designed to operate on two or more cellular frequency bands. For example, a dual-band base station antenna includes at least one or more low-band radiators and one or more high-band radiators. One known low-band radiator has a center feed, and a dipole or dipole pair disposed on the center feed. Each dipole comprises a pair of dipole arms having a length. As shown in fig. 1A and 1B, dipole arm 100 'includes a central axis 110' and a plurality of hollow tubes 120 'spaced apart along central axis 110'. The central shaft 110 'includes a shaft portion 111' and a plurality of circular flanges 112 'extending radially outward from the shaft portion 111', the flanges 112 'being integrally formed with the shaft portion 111'. The hollow tube 120 'is secured to the central shaft 110' by engaging the bottom of each central tube 120 'with a respective one of the flanges 112'.

The shaft portion 111 ' and the flange 112 ' of the central shaft 110 ' are integrally formed by cutting with a numerically controlled lathe, which results in high production cost. The center shaft 110' is easily deformed during high-speed cutting, resulting in difficulty in machining and a high defective rate. In addition, a large amount of raw materials need to be cut in lathe machining, and the material utilization rate is low.

The hollow tubes 120' are extruded from a raw material, cut into pieces, and then the bottom portion of each hollow tube is processed with high precision. This therefore results in a time consuming and laborious manufacture of the hollow tube 120' and a high production cost.

The bottom of each hollow tube 120 ' is fitted by rolling to a respective flange 112 ' of the central shaft 110 '. The rolling process is inefficient and sometimes prone to an untight fit between the inner surface of the hollow tube 120 'and the outer surface of the respective flange 112', which can affect subsequent performance parameters of the antenna.

Disclosure of Invention

It is an object of the present disclosure to provide a dipole arm assembly that overcomes at least one of the disadvantages of the prior art.

According to one aspect of the present disclosure, a dipole arm for a low-band radiator of a cellular base station antenna comprises: a central shaft; and at least one cylinder having a first end, a second end, and a peripheral wall between the first end and the second end, the first end having an end wall with a joint provided thereon, the cylinder being engaged with and disposed around the central axis by the joint.

In one embodiment, the second end is open to the outside.

In one embodiment, the cross-section of the at least one cylinder is circular or elliptical.

In one embodiment, the at least one barrel comprises a metallic material.

In one embodiment, the at least one cylinder includes a plurality of cylinders axially spaced along the central axis.

In one embodiment, the plurality of barrels have the same structure or different structures.

In one embodiment, the plurality of cylinders have the same diameter or different diameters, and have the same axial length or different axial lengths.

In one embodiment, the plurality of cylinders have sequentially increasing axial lengths along the central axis.

In one embodiment, the second ends of the plurality of barrels are open outwardly in the same direction.

In one embodiment, the at least one cylinder is mechanically and electrically engaged with the central shaft by an engagement.

In one embodiment, the engagement portion includes a hole disposed in the center of the end wall through which the central shaft passes.

In one embodiment, the engagement portion includes a projection extending axially inwardly from the end wall about the aperture.

In one embodiment, the protrusion extends axially inward a distance less than the axial length of the peripheral wall.

In one embodiment, the protrusion extends axially inward a distance less than one-half of the axial length of the peripheral wall.

In one embodiment, the protrusion extends axially inward a distance less than one quarter of the axial length of the peripheral wall.

In one embodiment, the holes and protrusions have a cross-section matching the size and shape of the central axis.

In one embodiment, the central shaft fits in the protrusion by an interference fit.

In one embodiment, the cross-sections of the central shafts have the same shape.

In one embodiment, the central axis is circular, polygonal or elliptical in cross-section.

In one embodiment, the central shaft is made of aluminum, aluminum alloy, or other metallic material.

In one embodiment, the space between the barrel and the central shaft is completely filled or partially filled with a dielectric material.

In one embodiment, the dipole arms have a length of substantially a quarter wavelength (λ/4) or a half wavelength (λ/2).

In one embodiment, the dipole arms and the second dipole arms in combination with the center feed form a low-band radiator that is part of a cellular base station antenna.

In one embodiment, adjacent barrels are positioned to form a radio frequency choke that interrupts current from a high band radiator included in a cellular base station antenna.

According to another aspect of the present disclosure, a method for fabricating a dipole arm comprises: extruding a metal feedstock to form a cylinder and cutting the cylinder into sections to form a central shaft; deep drawing a metal feedstock to form at least one barrel having a first end, a second end, and a peripheral wall therebetween, the first end having an end wall with a joint disposed thereon; the central shaft and the at least one cylinder are assembled together with a joint.

Drawings

Various aspects of the disclosure will be better understood upon reading the following detailed description in conjunction with the drawings in which:

fig. 1A and 1B are perspective and cross-sectional views of a conventional dipole arm;

FIG. 2 is a schematic diagram of a portion of a dual-band cellular basestation antenna;

fig. 3A and 3B are perspective and cross-sectional views of a dipole arm according to an embodiment of the present disclosure;

fig. 4 is a perspective view of a central axis of a dipole arm according to an embodiment of the present disclosure; and

fig. 5A and 5B are perspective and cross-sectional views of a cylinder of a dipole arm according to an embodiment of the present disclosure.

Detailed Description

The present disclosure will now be described with reference to the accompanying drawings, which illustrate several embodiments of the disclosure. It should be understood, however, that the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, the embodiments described below are intended to provide a more complete disclosure of the present disclosure, and to fully convey the scope of the disclosure to those skilled in the art. It is also to be understood that the embodiments disclosed herein can be combined in various ways to provide further additional embodiments.

It should be understood that like reference numerals refer to like elements throughout the several views. In the drawings, the size of some of the features may be varied for clarity.

It is to be understood that the terminology used in the description is for the purpose of describing particular embodiments only, and is not intended to be limiting of the disclosure. All terms (including technical and scientific terms) used in the specification have the meaning commonly understood by one of ordinary skill in the art unless otherwise defined. Well-known functions or constructions may not be described in detail for brevity and/or clarity.

As used in this specification, the singular forms "a", "an" and "the" include plural referents unless the content clearly dictates otherwise. The terms "comprising," "including," and "containing" when used in this specification specify the presence of stated features, but do not preclude the presence or addition of one or more other features. The term "and/or" as used in this specification includes any and all combinations of one or more of the associated listed items. The terms "between X and Y" and "between about X and Y" as used in the specification should be construed to include X and Y. The term "between about X and Y" as used herein means "between about X and about Y" and the term "from about X to Y" as used herein means "from about X to about Y".

In the description, when an element is referred to as being "on," "attached" to, "connected" to, "coupled" to, or "contacting" another element, etc., another element may be directly on, attached to, connected to, coupled to, or contacting the other element, or intervening elements may be present. In contrast, when an element is referred to as being "directly on," "directly attached to," directly connected to, "directly coupled to," or "directly contacting" another element, there are no intervening elements present. In the description, one feature is disposed "adjacent" another feature, and may mean that one feature has a portion overlapping with or above or below an adjacent feature.

In the specification, spatial relations such as "upper", "lower", "left", "right", "front", "rear", "high", "low", and the like may explain the relation of one feature to another feature in the drawings. It will be understood that the spatial relationship terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, features originally described as "below" other features may be described as "above" other features when the device in the figures is inverted. The device may also be otherwise oriented (rotated 90 degrees or at other orientations) and the relative spatial relationships may be interpreted accordingly.

The low-band radiator of a dual-band cellular basestation antenna will be disclosed. The following description will disclose numerous specific details including shapes and materials of dipole arms, and dielectric materials, etc. It will be apparent, however, to one skilled in the art that various modifications and/or substitutions can be made to the details described above, and certain details can be omitted, without departing from the scope and spirit of the disclosure.

In some embodiments, the low frequency band may refer to a frequency band such as 698-960 MHz or a portion thereof, while the high frequency band may refer to a frequency band such as 1710 MHz-2690 MHz or a portion thereof. However, the present disclosure is not limited to these frequency bands. For example, the low frequency band may also include low frequencies, such as 600MHz, and/or the high frequency band may also include high frequencies, such as 1400 MHz. A "low-band radiator" refers to a radiator configured to operate in a low-frequency band, and a "high-band radiator" refers to a radiator configured to operate in a high-frequency band. Throughout this disclosure, "dual band" includes at least one low band and one high band. It should also be understood that the term "dual band antenna" refers not only to antennas operating in the low and high frequency bands, but also to antennas operating in one or more additional frequency bands (e.g., the 3.5GHz band or the 5GHz band).

Embodiments of the present disclosure relate generally to dual-band cellular base station antennas. The use of dual band antennas may enable operators of cellular communication systems to use a single type of antenna to cover multiple frequency bands, which allows operators to reduce the number of antennas in their networks, thereby reducing tower rental costs, while speeding marketability. Dual-band cellular basestation antennas support multiple frequency bands and technical standards.

More particularly, embodiments of the present disclosure relate to dual band antennas for cellular base stations. In some embodiments, the dual band antenna may be configured to operate in the low frequency band of 698MHz to 960MHz or a portion thereof and the high frequency band of 1710MHz to 2690MHz or a portion thereof.

Figure 2 shows a schematic view of a part of a dual band cellular basestation antenna 1. The dual-band cellular basestation antenna 1 comprises a plurality of low-band radiators 10 (only one shown in figure 2) and a plurality of high-band radiators 20. In the example shown, the high-band radiator 20 comprises four high-band radiators arranged in a 2X2 matrix, and one low-band radiator 10 is interposed between the four high-band radiators.

As shown in fig. 2, the low-band radiator 10 includes a center feed 11 in a cross shape, and a dipole 12 inclined at-45 degrees and a dipole 13 inclined at +45 degrees, which are arranged on the center feed 11 and are perpendicular to each other. The center feed 11 includes two cross-interlocked Printed Circuit Boards (PCBs) on each of which a feed line for a dipole 12 inclined at-45 degrees and a dipole 13 inclined at +45 degrees is formed. The center feed 11 supports the-45 degree-inclined dipole 12 and the +45 degree-inclined dipole 13 at a height above the reflection plate of the antenna 1, preferably at a height of a quarter wavelength (λ/4).

Four high-band radiators 20 are arranged around the four quadrants, respectively. By repeating the pattern shown in fig. 2, the entire base station antenna 1 can be constructed.

Dipole 12, which is inclined at-45 degrees, includes a pair of dipole arms 12A and 12B having a certain length, and dipole 13, which is inclined at +45 degrees, includes a pair of dipole arms 13A and 13B having a certain length. Dipole arms 12A and 12B may have the same or different lengths as dipole arms 13A and 13B. In some embodiments, dipole arms 12A, 12B, 13A, and 13B may have a length of approximately one-quarter wavelength (λ/4) or one-half wavelength (λ/2), although embodiments of the present disclosure are not so limited.

Fig. 3A and 3B show a dipole arm 100 for a low-band radiator 10 of a cellular base station antenna 1, which may be used to implement any of the dipole arms 12A, 12B, 13A and 13B shown in fig. 2. Dipole arm 100 includes a central axis 110 and a plurality of cylinders 120, which cylinders 120 are axially spaced along central axis 110 and arranged around central axis 110. In the illustrated example, dipole arm 100 includes three cylinders 120a, 120b and 120c, but it is contemplated that dipole arm 100 may include more or less than three cylinders 120.

The dipole arm arrangement shown in fig. 3A and 3B creates a series of coaxial RF chokes along the length of the dipole arm 100. Specifically, the gap between the cylinder 120a and the cylinder 120b acts as a first in-line choke, and the gap between the cylinder 120b and the cylinder 120c acts as a second in-line choke. These gaps can interrupt the RF signal current emitted by the high-band radiator. Thus, RF energy emitted by the high-band radiator will not flow on the dipole arm 100, whereby the low-band radiator has no or little effect on the radiation pattern of the high-band radiator. In other words, the cylinder 120 serves to form a series of RF chokes along the dipole arm 100, which makes the dipole arm almost invisible to RF energy in the high frequency band.

In some embodiments, the space between the barrel 120 and the central shaft 110 may be filled with air. Alternatively, the space between the barrel 120 and the central shaft 110 may be completely filled or partially filled with a solid or foam-like dielectric material.

As shown in fig. 4, the central shaft 110 has a straight cylindrical shape and is made of aluminum, aluminum alloy, or other metal material. The cross-section of the central shaft 110 is circular; it is contemplated that the cross-section of the central shaft 110 may be polygonal or elliptical in shape. The central shaft 110 may have a constant cross-section. For example, in embodiments where the central shaft 110 has a circular cross-section, the diameter of the cross-section may be constant along the entire length of the central shaft 110. In some embodiments, the end of the central shaft 110 that is mounted to the center feed 111 may have a different cross-section than other portions of the central shaft 110 to facilitate mounting the central shaft 110 to the center feed 111. In an exemplary embodiment, the central shaft 110 may have a length between 99mm and 104mm and a diameter of 3.0 mm.

As shown in fig. 5A and 5B, each cylinder 120 has two ends, and a peripheral wall 125 between the two ends. One end of each cylinder 120 has an end wall 121, and the other end is open to the outside. The cylinder 120 may be made of aluminum, aluminum alloy, or other metal material. Each cylinder 120 has a circular cross-section; it is contemplated that in other embodiments, the barrel 120 may instead have an oval, rectangular, etc. cross-section. The end wall 121 is provided with an engagement portion 122 that mechanically and electrically engages the central shaft 110.

In some embodiments, joint 122 includes an aperture 123 centrally disposed in end wall 121, and a protrusion 124 extending axially inward from end wall 121 about aperture 123. The hole 123 and the protrusion 124 may have a cross-section matching the size and shape of the corresponding portion of the central shaft 110 to which the cylinder 120 is to be mounted, whereby the central shaft 110 can pass through the protrusion 124 and/or the hole 123 and the outer surface of the central shaft 110 closely conforms to the inner surface of the protrusion 124 when the cylinder 120 is mounted on the central shaft 110. The protrusion 124 extends axially inward a distance less than the axial length of the peripheral wall 125, in some embodiments less than one-half the axial length of the peripheral wall 125, and in other embodiments less than one-quarter the axial length of the peripheral wall 125.

The plurality of barrels 120 may have the same or different structures. In some embodiments, as shown in fig. 5A and 5B, the peripheral wall 125 of the cylinder 120c is provided with an aperture 126 and a cutout 127 for connection and fixation with the PCB assembly of the center feed 111; while the peripheral walls of the cylinders 120a and 120b are not provided with any openings or cutouts.

The plurality of barrels 120 may have the same or different diameters, and the same or different axial lengths. In some embodiments, the multiple barrels 120 may have the same diameter (e.g., 16.0mm), but different axial lengths, e.g., the axial length of barrel 120c (e.g., 31.5mm) is greater than the axial length of barrel 120b (e.g., 28.5mm), and the axial length of barrel 120b is greater than the axial length of barrel 120a (e.g., 25.5 mm).

Overall, the cylinder 120 and the central shaft 110 have optimized dimensions such that the radiation pattern of the high-band radiator 20 is largely unaffected by the low-band radiator 10.

A method for producing a dipole arm 100 is described below in connection with fig. 3A-3B. First, a metal stock is extruded to form a cylinder and the cylinder is cut into sections to form the central shaft 110. The deep drawing of the metal stock forms a plurality of barrels 120a, 120b, and 120 c. Then, the center shaft 110 is inserted into the protrusions of the cylinder bodies 120a, 120b, and 120c in such a manner that the openings of the plurality of cylinder bodies 120 face in the same direction, and the center shaft 110 and the cylinder bodies 120a, 120b, and 120c are assembled together by interference fit between the outer surface of the center shaft 110 and the inner surface of the protrusion 124, thereby forming the dipole arm 100.

The dipole arm 100 of the present disclosure is suitable for high volume automated production, has high quality stability, and is capable of achieving better Passive Intermodulation (PIM) distortion performance.

Although exemplary embodiments of the present disclosure have been described, it will be understood by those skilled in the art that various changes and modifications can be made to the exemplary embodiments of the present disclosure without substantially departing from the spirit and scope of the present disclosure. Accordingly, all changes and modifications are intended to be included within the scope of the present disclosure as defined in the appended claims. The disclosure is defined by the following claims, with equivalents of the claims to be included therein.