Radiator components for base station antennas

Abstract

The invention relates to a radiator assembly for a base station antenna, the radiator assembly having a central axis (10) and two cross-arranged dipoles, each dipole comprising two dipole arms, and each dipole arm having a radiating surface (12), the radiating surface having an outer contour. The radiator assembly comprises a conductive annular element (3), the annular element (3) being mounted above each radiating surface (12). The annular element (3) is constructed to be enclosed and has an inner contour (14), the inner contour of the annular element conforming to the outer contour line of the combination of all four radiating surfaces. The radiator assembly is compact and broadband.

Description

Technical Field

[0001] The present invention relates to the field of base station antennas, and more particularly to a radiator assembly for a base station antenna. Background Art

[0002] A mobile communication network includes a large number of base stations, each of which includes a base station antenna for receiving and sending communication signals. The base station antenna may include many radiator components, which may also be referred to as radiating elements or antenna elements. The cost of a single radiator component has a significant impact on the cost of the entire base station antenna. It is desirable to miniaturize the size and minimize the cost of the radiator component.

[0003] A large number of dual-polarized radiator components have been developed in 2G / 3G / 4G / LTE systems, which are designed to operate in the 2GHz band, which can cover a frequency range of 1.71 to 2.69 GHz, for example. In addition, the 1.4 / 1.5GHz band is valuable in International Mobile Telecommunications (IMT) services. The 1.4 / 1.5GHz band can, for example, cover a frequency range of 1427 to 1518 MHz. Currently, the 1427 to 1518 MHz band has been used for IMT services in Japan. Many European countries support a frequency range of 1452 to 1492 MHz, and some European countries also support a frequency range of 1427 to 1518 MHz. In addition, the United States supports a frequency range of 1695 to 1700 MHz for 5G communications. Therefore, in the design of base station antennas, it is desirable to broaden the operating frequency band range of radiator components. It is particularly desirable to broaden the operating frequency band range of the radiator assembly to cover not only the 1.4 / 1.5 GHz band but also the 1.695-2.69 GHz band. Summary of the invention

[0004] The object of the present invention is to provide a radiator assembly for a base station antenna which is compact and broadband.

[0005] The object is achieved by a radiator assembly for a base station antenna, the radiator assembly having a central axis and two cross-arranged dipoles, each dipole comprising two dipole arms, each dipole arm having a radiating surface, the radiating surface having an outer contour, wherein the radiator assembly comprises a conductive annular element, the annular element is mounted above each radiating surface, the annular element is configured to be circumferentially closed and has an inner contour, the inner contour of the annular element conforms to the outer contour line of the combination of all four radiating surfaces, wherein the conformity is defined as:

[0006] In the projection along the central axis onto a projection plane perpendicular to the central axis,

[0007] - the inner contour of the annular element has a projected inner contour line, and the projected inner contour line surrounds the first area; and

[0008] - the outer contour of each radiation surface has a projected outer contour line, each two adjacent projected outer contour lines are connected by an imaginary connecting line, each imaginary connecting line is a chord of a corresponding imaginary circular arc line, each circular arc line is concentric with the central axis and the radius of the circular arc line is 1 / 2 of the maximum radius of the outer contour line of the projection of the radiation surface, the outer contour lines of each projection and each connecting line jointly define a surrounding closed maximum outer contour line, and the surrounding closed maximum outer contour line encloses the second area;

[0009] The first area and the second area overlap by at least 90%. In other words, the overlapping area of ​​the first area and the second area is more than 90% of the larger area of ​​the first area and the second area.

[0010] Here, each radiating surface can be designed according to a higher center frequency. The resonance of the ring element expands the frequency band toward the low frequency end. Since the definition of "the inner contour of the ring element follows the outer contour line of the combination of all four radiating surfaces" in the sense of the present invention, the expansion of the frequency band toward the low frequency end and the compact size are advantageously achieved. Compared with a radiator component without a ring element, the radiator component with a ring element according to the present invention can have a reduced planar size.

[0011] In the sense of the present invention, when describing the orientation of components of a radiator assembly, the terms "above" and "below" are to be understood as relative orientations. For example, the expression "component A is mounted above component B" means that component A is mounted further outward from the reflector plate than component B, or that component A is arranged on the side of component B that faces away from the reflector plate or the bottom of the radiator assembly.

[0012] In some embodiments, the radiator assembly is configured to cover both the 1.4 / 1.5 GHz frequency band and the 2 GHz frequency band.

[0013] In some embodiments, the first area and the second area may overlap by at least 95%, such as at least 98%. In other words, the overlapping area may be more than 95% of the larger area, such as more than 98% of the larger area.

[0014] In some embodiments, the radiating surfaces may be formed on a common printed circuit board. In other embodiments, the dipole arms may be formed as a separate component, such as a metal component, and may be mounted in a support.

[0015] In some embodiments, each radiating surface may have an outer contour that deviates from a rectangle.

[0016] In some embodiments, with reference to the central axis, the outer contour line of the projection of the radiating surface may have a width that first increases and then decreases from the radial inside to the radial outside. For example, the radiating surface may be configured to be leaf-shaped, elliptical or spindle-shaped. Perforations may be provided in the radiating surface. The radiating surface may also be configured to be comprehensive.

[0017] In some embodiments, the printed circuit board may be mounted above the reflective plate, and the radiator assembly may include a plurality of spacers, and the annular element may be mounted above the printed circuit board at a predetermined interval through the spacers.

[0018] In some embodiments, when viewed along the central axis, there may be a gap between every two adjacent radiation surfaces, and the annular element may have a region extending into each of the gaps.

[0019] In some embodiments, the annular element may have a greater width in the region than in the remaining region, viewed along the central axis.

[0020] In some embodiments, the annular element may be made of a metal plate. In other embodiments, the annular element may include a conductive layer on a printed circuit board.

[0021] In some embodiments, the radiator assembly may have a director, and the director may be mounted above the ring element.

[0022] In some embodiments, each radiating surface may be formed on a common printed circuit board, and the director may be supported on the printed circuit board by a support, and the support may have a plurality of supporting points distributed around the central axis on the printed circuit board.

[0023] In some embodiments, the director may be configured as a prismatic metal plate, and the prismatic metal plate may be oriented such that, viewed along the central axis, each corner of the metal plate is located in the region of the gap between adjacent radiating surfaces.

[0024] In some embodiments, one of a pair of corners of the metal plate may be chamfered.

[0025] In some embodiments, in the projection on the projection plane along the central axis, the outer contour of the director has a projected outer contour line, the projected outer contour line of the director surrounds a third area, the third area can overlap with the projection of the annular element in the region of each corner, and at least 90% of the third area can be within the inner contour line of the projection of the annular element.

[0026] It should be noted that the technical features mentioned above and the technical features to be mentioned later can be combined with each other arbitrarily as long as they are not contradictory. All technically feasible feature combinations are technical contents clearly recorded in this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be described in more detail below with reference to the accompanying drawings with the aid of specific embodiments. The schematic drawings are briefly described as follows:

[0028] Figure 1 is a perspective view of a radiator assembly for a base station antenna according to an embodiment of the present invention;

[0029] Figure 2 Yes Figure 1 a side view of a radiator assembly;

[0030] Figure 3 Yes Figure 1 A top view of a radiator assembly;

[0031] Figure 4 Yes Figure 1 A perspective view of some components of a radiator assembly;

[0032] Figure 5 Is a description Figure 1 A simplified schematic diagram of the projection of each radiating surface of the radiator assembly along the central axis in a projection plane perpendicular to the central axis;

[0033] Figure 6 is a top view of a ring element according to another embodiment of the present invention; and

[0034] Figure 7 FIG. 1 is a perspective view of a radiator assembly for a base station antenna according to another embodiment of the present invention. DETAILED DESCRIPTION

[0035] Figure 1 is a perspective view of a radiator assembly for a base station antenna according to one embodiment of the present invention, Figure 2 Yes Figure 1 a side view of a radiator assembly, and Figure 3 Yes Figure 1 A top view of a radiator assembly.

[0036] exist Figures 1 to 3 A small part of the reflector plate 1 is depicted in FIG. An array of radiator assemblies may be mounted on the reflector plate 1, one of which is shown in FIG. Figures 1 to 3 In. Figures 1 to 3 In the embodiment, the reflector plate 1 is arranged horizontally, and the radiator assembly extends upward from the reflector plate. It is easy to imagine that in actual use, the reflector plate typically extends substantially in the vertical direction, and each radiator assembly extends forward from the reflector plate 1. Therefore, the following discussion is based on Figures 1 to 3 The radiator assembly is introduced with reference to the orientation shown in FIG. 1 , however, it is easy to imagine that when the base station antenna including each radiator assembly is installed and used, each radiator assembly and the reflector plate 1 will be rotated by about 90°.

[0037] The radiator assembly shown comprises two cross-arranged dipoles, each dipole comprising two dipole arms, each dipole arm having a corresponding radiating surface 12, which can be fed with radio frequency signals. In some embodiments, each radiating surface 12 is formed on a common printed circuit board 2, however other embodiments are also possible, for example including a metal plate radiating surface or a molded metal radiating surface. Each radiating surface 12 may have an outer contour that deviates from a rectangle and surrounds a central axis 10 of the radiator assembly. There may be a gap between each two adjacent radiating surfaces 12. The gap is an electrical gap, so a physical gap on the printed circuit board 2, such as a slot cut in the printed circuit board 2, may not be mandatory. In the embodiment shown, a pair of so-called "feed rod" printed circuit boards are used to support the printed circuit board 2 in front of the reflector 1.

[0038] A ring element 3 can be installed above the printed circuit board 2 at a predetermined interval by means of a plurality of distributed spacers 11. In some embodiments not shown, one or more (for example, 1, 2, 3 or more) additional ring elements can also be installed, which can be installed above or below the printed circuit board 2. The ring element 3 is configured to be enclosed and has an inner contour 14. The ring element 3 can be made of a metal plate. In some other embodiments, the ring element 3 can include a printed circuit board, and the printed circuit board can have an enclosed conductive layer. The ring element 3 can be a two-dimensional or three-dimensional component. Through the resonance of the ring element 3, the working frequency band can be expanded to the low frequency end. At the same time, the planar size of the radiating element can be reduced accordingly.

[0039] A director 4 may be mounted above the annular element 3. The director 4 may be supported on the printed circuit board 2 by a support 13. The support 13 may have a plurality of support points distributed around the central axis 10 on the printed circuit board 2. The director 4 may be configured as a prismatic metal plate. The metal plate may be oriented so that, when viewed along the central axis 10, each corner of the metal plate is in the region of the gap between adjacent radiation surfaces 12. One pair of corners of the metal plate may be chamfered. In the projection on the projection plane along the central axis 10, the outer contour of the director 4 has a projected outer contour line, and the outer contour line of the projection of the director surrounds a third area. The third area may overlap with the projection of the annular element 3 in the region of each corner, and at least 90% of the third area may be within the inner contour line of the projection of the annular element 3. The director 4 may facilitate better impedance matching in the radiator assembly, and may help control the radiation direction of the radio frequency radiation emitted by the radiator assembly and / or may help narrow the beam width of the emitted radio frequency radiation.

[0040] As mentioned above, in Figures 1 to 3 In the figure, the reflector 1 is described in a horizontal state, and the radiator assembly is above the reflector 1. In the installed state of the base station antenna, the reflector 1 can have different orientations, for example, the reflector 1 can be oriented toward the sky at an angle relative to the horizontal plane, or can be oriented perpendicular to the horizontal plane, or can be oriented toward the ground at an angle relative to the horizontal plane. Here, although the absolute orientation of the radiator assembly changes, the relative orientation of the radiator assembly and the reflector 1 remains unchanged. Therefore, here, the terms "above" and "below" should be understood as relative orientations. For example, the statement "the annular element 3 is installed above the printed circuit board 2" means that if the reflector is installed to extend along the vertical axis, then the annular element 3 is installed farther outward from the reflector 1 than the printed circuit board 2.

[0041] Figure 4 Yes Figure 1 A perspective view of some components of the radiator assembly of FIG. 1 , wherein the director 4, the support 13 and the ring element 3 are omitted so that the details of the printed circuit board 2 can be more clearly described. Figure 4 In the figure, the outer contour of each radiation surface 12 is schematically described by a dotted line.

[0042] Figure 5 1 is a schematic diagram describing the projection of each radiation surface 12 along the central axis 10 in a projection plane perpendicular to the central axis. Each radiation surface 12 has a projected outer contour line 21, 22, 23, 24, which have gaps between them. In order to form a surrounding closed outer contour line for the combination of all four radiation surfaces 12, Figure 5In the embodiment, imaginary connecting lines a, c, e, g are defined as connecting lines between adjacent outer contour lines 21, 22, 23, 24. The connecting lines a, c, e, g are chords of imaginary arc lines, which are concentric with the central axis 10 and whose radius is 1 / 2 of the maximum radius R of the outer contour lines 21, 22, 23, 24. The outer contour lines 21, 22, 23, 24 and the connecting lines a, c, e, g can jointly define a maximum outer contour line that is enclosed, which includes the connecting line a, a line segment b between the connecting lines a and c outside the outer contour line 22, the connecting line c, a line segment d between the connecting lines c and e outside the outer contour line 23, the connecting line e, a line segment f between the connecting lines e and g outside the outer contour line 24, and the connecting line g, a line segment h between the connecting lines g and a outside the outer contour line 21.

[0043] The inner contour 14 of the ring element 3 may "comply" with the outer contour line of the combination of all four radiating surfaces 12. Here, the inner contour 14 of the ring element 3 is considered to "comply" with the outer contour line of the combination of all four radiating surfaces 12 if the following conditions are met:

[0044] In a projection along the central axis 10 onto a projection plane perpendicular to the central axis,

[0045] - the inner contour 14 of the ring element 3 has a projected inner contour line, which encloses the first area; and

[0046] The outer contour of each radiation surface 12 has projected outer contour lines 21, 22, 23, 24 (see Figure 5 ), the outer contour lines 21, 22, 23, 24 of every two adjacent projections (i.e., 21, 22; 22, 23; 23, 24; 24, 21) are connected by imaginary connecting lines a, c, e, g, each imaginary connecting line a, c, e, g is a chord of a corresponding imaginary circular arc, each circular arc is concentric with the central axis 10 and the radius of the circular arc is 1 / 2 of the maximum radius R of the outer contour lines 21, 22, 23, 24 of the projection of the radiation surface 12, the outer contour lines 21, 22, 23, 24 of each projection and the connecting lines a, c, e, g together define a surrounding closed maximum outer contour line, and the surrounding closed maximum outer contour line encloses the second area; and

[0047] - said first area and said second area overlap by at least 90%.

[0048] In some embodiments, the first area and the second area may overlap by at least 95%. In other embodiments, the first area and the second area may overlap by an area ranging from 92% to 98%.

[0049] Figure 6 FIG. 2 is a top view of a ring element 3 according to another embodiment of the present invention. Figure 3 The implementation method is different in Figure 6 In an embodiment, the ring element 3 may have a substantially constant width when viewed along the central axis 10. When viewed along the central axis 10, the ring element 3 may have regions r1, r2, r3, r4 extending into the respective gaps.

[0050] Figure 7 FIG. 2 is a perspective view of a radiator assembly for a base station antenna according to another embodiment of the present invention. Figure 1 The main difference between the implementation methods is that Figure 7 The radiator assembly comprises two annular elements 3, which are mounted above the printed circuit board 2, and the inner contour of at least one of the annular elements 3 can follow the outer contour line of the combination of all four radiating surfaces 12. Figure 1 Description of implementation methods.

[0051] It should be noted that the terms used herein are for the purpose of illustrating specific aspects only and are not intended to limit the disclosure. As used herein, the singular forms "a" and "the one" shall include the plural forms unless the context clearly states otherwise. It is understood that the terms "include" and "comprises" and other similar terms, when used in the application documents, specify the existence of the stated operations, elements and / or parts, without excluding the existence or addition of one or more other operations, elements, parts and / or combinations thereof. As used herein, the term "and / or" includes all arbitrary combinations of one or more related enumerated items. In the description of the drawings, similar reference numerals always represent similar elements.

[0052] The thickness of the elements in the accompanying drawings can be exaggerated for the sake of clarity. It is also understood that if an element is referred to as being on another element, coupled to another element or connected to another element, then the element can be directly formed on the other element, coupled to it or connected to it, or one or more intervening elements can be arranged between them. On the contrary, if the expressions "directly on...", "directly coupled to..." and "directly connected to..." are used herein, then there is no intervening element. Other words used to illustrate the relationship between elements should be similarly interpreted, such as "between..." and "directly between...", "attachment" and "direct attachment", "adjacent" and "directly adjacent", etc.

[0053] Terms such as "top," "bottom," "above," "below," "above," "below," etc. are used herein to describe the relationship of one element, layer or region to another element, layer or region as illustrated in the drawings. It will be understood that these terms are intended to encompass other orientations of the device in addition to the orientation depicted in the drawings.

[0054] It is to be understood that although the terms "first", "second", etc. may be used herein to describe different elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Therefore, the first element may be referred to as the second element without departing from the teachings of the present invention.

[0055] It is also conceivable that all exemplary embodiments disclosed herein can be combined with one another in any desired manner.

[0056] Finally, it should be pointed out that the above embodiments are only used to understand the present invention, and do not limit the protection scope of the present invention. For those skilled in the art, modifications can be made based on the above embodiments, and these modifications do not depart from the protection scope of the present invention.

Claims

1. A radiator assembly for a base station antenna, the radiator assembly having a central axis (10) and two cross-arranged dipoles, each dipole comprising two dipole arms, each dipole arm having a radiating surface (12), the radiating surface having an outer contour, characterized in that: The radiator assembly comprises a conductive annular element (3), which is mounted above each radiating surface (12), the annular element (3) being configured to be circumferentially closed and having an inner contour (14), the inner contour of the annular element conforming to the outer contour line of the combination of all four radiating surfaces, wherein the conformity is defined as: In a projection along the central axis (10) onto a projection plane perpendicular to the central axis, - the inner contour (14) of the annular element (3) has a projected inner contour line, which encloses the first area; and - the outer contours of each radiation surface (12) respectively have projected outer contour lines (21, 22, 23, 24), and every two adjacent projected outer contour lines are connected by an imaginary connecting line (a, c, e, g), each imaginary connecting line is a chord of a corresponding imaginary circular arc line, each circular arc line is concentric with the central axis, and the radius of the circular arc line is 1 / 2 of the maximum radius (R) of the projected outer contour line (21, 22, 23, 24) of the radiation surface, and each projected outer contour line (21, 22, 23, 24) and each connecting line (a, c, e, g) jointly define a surrounding closed maximum outer contour line, and the surrounding closed maximum outer contour line encloses the second area; Wherein, the first area and the second area overlap by at least 90%.

2. The radiator assembly for a base station antenna according to claim 1, characterized in that: The first area and the second area overlap by at least 95%.

3. The radiator assembly for a base station antenna according to claim 2, characterized in that: The first area and the second area overlap by at least 98%.

4. The radiator assembly for a base station antenna according to any one of claims 1 to 3, characterized in that: The radiating surfaces (12) are formed on a common printed circuit board (2).

5. The radiator assembly for a base station antenna according to any one of claims 1 to 3, characterized in that: Each radiation surface (12) has an outer contour that deviates from a rectangle.

6. The radiator assembly for a base station antenna according to claim 5, characterized in that: With reference to the central axis (10), from radially inside to radially outside, the outer contour line (21, 22, 23, 24) of the projection of the radiating surface (12) has a width which first increases and then decreases.

7. The radiator assembly for a base station antenna according to claim 4, characterized in that: The printed circuit board (2) is mounted above the reflector plate (1), and the radiator assembly comprises a plurality of spacers (11), and the annular element (3) is mounted above the printed circuit board (2) at a predetermined interval via the spacers (11).

8. The radiator assembly for a base station antenna according to any one of claims 1 to 3, characterized in that: When viewed along the central axis (10), there is a gap between every two adjacent radiating surfaces (12), and the ring element (3) has regions (r1, r2, r3, r4) extending into each of the gaps.

9. The radiator assembly for a base station antenna according to claim 8, characterized in that: Viewed along the central axis (10), the annular element has a greater width in the regions (r1, r2, r3, r4) than in the remaining regions.

10. The radiator assembly for a base station antenna according to any one of claims 1 to 3, characterized in that: The annular element (3) is made of a metal plate, or the annular element (3) comprises a conductive layer on a printed circuit board.

11. The radiator assembly for a base station antenna according to any one of claims 1 to 3, characterized in that: The radiator assembly has a director (4) which is mounted above the annular element (3).

12. The radiator assembly for a base station antenna according to claim 11, characterized in that: The radiation surfaces (12) are formed on a common printed circuit board (2), the director (4) is supported on the printed circuit board (2) via a support (13), and the support (13) has a plurality of support points distributed around the central axis (10) on the printed circuit board (2).

13. The radiator assembly for a base station antenna according to claim 11, characterized in that: The director (4) is designed as a prismatic metal plate which is oriented such that, viewed along the central axis (10), the individual corners of the metal plate are located in the region of the gaps between adjacent radiating surfaces (12).

14. The radiator assembly for a base station antenna according to claim 13, characterized in that: One pair of corners of the metal plate is chamfered.

15. The radiator assembly for a base station antenna according to claim 13, characterized in that: In the projection along the center axis (10) on the projection plane, the outer contour of the director has a projected outer contour line, the projected outer contour line of the director surrounds a third area, the third area overlaps with the projection of the annular element (3) in the region of each corner, and at least 90% of the third area is within the inner contour line of the projection of the annular element (3).

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