(19)
(11) EP 4 266 489 A1

(12) EUROPEAN PATENT APPLICATION
published in accordance with Art. 153(4) EPC

(43) Date of publication:
25.10.2023 Bulletin 2023/43

(21) Application number: 22893991.4

(22) Date of filing: 14.04.2022
(51) International Patent Classification (IPC): 
H01Q 1/12(2006.01)
(86) International application number:
PCT/CN2022/086852
(87) International publication number:
WO 2023/103244 (15.06.2023 Gazette 2023/24)
(84) Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated Extension States:
BA ME
Designated Validation States:
KH MA MD TN

(30) Priority: 09.12.2021 CN 202111502288

(71) Applicant: Guangdong Broadradio Communication Technology Co., Ltd
Huangpu Industry District Guangzhou, Guangdong 510000 (CN)

(72) Inventors:
  • ZHANG, Shao
    Guangdong 510000 (CN)
  • WU, Biqun
    Guangdong 510000 (CN)
  • WU, Zehai
    Guangdong 510000 (CN)
  • ZHANG, Peng
    Guangdong 510000 (CN)
  • LUO, Benbo
    Guangdong 510000 (CN)

(74) Representative: Chung, Hoi Kan 
Mandarin IP Limited 7 Cherry Trees Great Shelford
Cambridge, Cambridgeshire CB22 5XA
Cambridge, Cambridgeshire CB22 5XA (GB)

   


(54) DOUBLE-LAYER DIRECTOR AND MULTI-FREQUENCY BASE STATION ANTENNA ARRAY


(57) A double-layered director includes a first director and a second director installed above the first director, and the second director includes a dielectric substrate and a split copper foil installed on the dielectric substrate. The present invention arranges a split copper foil on the dielectric substrate. This not only weakens the influence of the resonant current of the director on the high-frequency radiation unit itself, but also simplifies the boundary of the radiation unit, and reduces the coupling and mutual interference between the high-frequency and low-frequency radiation units, and avoids the superposition of scattered waves.




Description

TECHNICAL FIELD



[0001] The present application relates to the technical field of base station antennas, in particular to a double-layered director and a multi-frequency base station antenna array using the same.

BACKGROUND



[0002] With the rapid development of the mobile communication industry, consumers' requirements for mobile network are gradually increasing. Moreover, in the present environment where 2G, 3G, 4G and 5G networks coexist and tower resources are rare, base station antennas are required to develop in the direction of multi-frequency and miniaturization. Therefore, multi-port broadband base station antennas are increasingly favored by the market.

[0003] The multi-port broadband base station antenna can form more antenna arrays without increasing the antenna width, which will reduce the distance between the antenna arrays and increase the mutual influence between the antenna arrays. In this case, it is required to have a consistent and stable radiation pattern within the operating frequency band. A good choice is to add a director above the radiating unit. Use of the parasitic effect between the director and the radiating unit can make the antenna radiation wave radiate in the normal radiation direction, thereby realizing the reduction of the antenna width by increasing the height of the array. However, when the number of directors is increased or the size there of is large, resonance will occur during operation of the antenna, hence affecting the performance of the antenna itself.

SUMMARY



[0004] The object of the present invention is to at least solve one of the drawbacks in the prior art proposed in the background technology, and to realize the object of the present invention, the following technical solution is proposed:

[0005] In a first aspect, the present invention proposes a double-layered director. The double-layered director includes a first director and a second director installed above the first director, and the second director includes a dielectric substrate and a split copper foil installed on the dielectric substrate.

[0006] Preferably, the split copper foil includes a plurality of small copper foils, and the plurality of small copper foils are circumferentially arranged at intervals around a center of the second director.

[0007] Preferably, the number of the small copper foils is at least 4.

[0008] Preferably, the number of the small copper foils is at least 12.

[0009] Preferably, the length of the small copper foils is less than 0.25λ, where λ is the wavelength of the center frequency of the antenna.

[0010] Preferably, the small copper foils are of a sector or annular sectoral shape.

[0011] Preferably, the first director is made of a whole piece of metal sheet.

[0012] Preferably, the shape of the metal sheet is circular or polygonal.

[0013] A second aspect of the present invention proposes a multi-frequency base station antenna array. it includes a reflector and a high-frequency array and a low-frequency array arranged on the reflector, the high-frequency array includes several high-frequency radiation units, and the low-frequency array includes several low-frequency radiation units, each high-frequency radiation unit is distributed below a corresponding low-frequency radiation unit, and a double-layered director according to the first aspect is also arranged directly above a corresponding high-frequency radiation unit.

[0014] Preferably, the number of the high-frequency array and the low-frequency array is two rows.

[0015] The present invention brings the following good effects.

[0016] The present invention arranges a split copper foil on the dielectric substrate. This not only weakens the influence of the resonant current of the director on the high-frequency radiation unit itself, but also simplifies the boundary of the radiation unit, and reduces the coupling and mutual interference between the high-frequency and low-frequency radiation units, and avoids the superposition of scattered waves which otherwise will cause the pattern distortion. This in turn enables the multi-frequency base station antenna to have consistent and stable horizontal half-power beamwidth and gain within the operating frequency band.

BRIEF DESCRIPTION OF DRAWINGS



[0017] 

FIG. 1 is a schematic diagram of the overall structure of a double-layered director of the present invention;

FIG. 2 is a top schematic plane view of 4 small copper foils in a double-layered director of the present invention;

FIG. 3 is a schematic top plan view of sectoral shaped small copper foils in a double-layered director of the present invention;

FIG. 4 is a schematic diagram of the overall structure of a multi-frequency base station antenna array of the present invention; and

FIG. 5 is a schematic diagram showing the change of the half-power beamwidth of the horizontal plane pattern of the antenna array after loading different types of double-layered directors.


Reference numerals:



[0018] 1. First director; 2. Second director; 3. High-frequency radiation unit; 4. Low-frequency radiation unit; 21. Split copper foil; 22. Dielectric substrate; 211. Small copper foil.

DETAILED DESCRIPTION OF THE EMBODIMENTS



[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, embodiments of the present invention. These drawings are all simplified schematic diagrams, and only illustrate the basic structure of the present invention in a schematic manner, so the drawings only show the configurations related to the present invention. Based on the embodiments of the present invention, all other embodiments obtained by person of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

[0020] It should be noted that when an element is referred to as being "mounted on" another element, it can be directly on the other element or there can also be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or an intervening element may also be present.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. Herein, the terms used in the description of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. As used herein, the term "and" includes any and all combinations of one or more of the associated listed items.

[0022] Please refer to FIGs. 1-5. A first aspect of the embodiment of the present invention proposes a double-layered director, which is mainly applied to a multi-frequency base station antenna array. As shown in FIG. 1, the double-layered director includes a first director 1 and a second director 2, and the second director 2 is installed directly above the first director 1. Specifically, the first director 1 and the second director 2 may be connected and fixed through an insulating support post.

[0023] Preferably, the first director 1 is constructed of a whole piece of circular metal sheet, and its diameter is between 0.15λ-0.5λ, where λ is the wavelength of the center frequency of the antenna. In addition, the metal sheet can also be a square or polygonal metal sheet. It is not limited to a circular shape, and those skilled in the art can set it according to actual need.

[0024] In this embodiment, the second director 2 is a split director, which is made of a PCB. The second director 2 includes a dielectric substrate 22 and a split copper foil 21 installed on the dielectric substrate 22. Here, the dielectric substrate 22 plays a role of supporting the split copper foil 21.

[0025] The split copper foil 21 includes a plurality of small copper foils 211, each of which is a lobe, and the plurality of small copper foils 211 are arranged circumferentially around a center of the second director 2 at intervals.

[0026] In this embodiment, the number of the small copper foils 211 is at least 4, for example, it may be 4, 5, 6 and so on. As shown in FIG. 2, it is a schematic top view of four small copper foils in a double-layered director of the present invention.

[0027] In this embodiment, the shape of the small copper foil 211 may be a sectoral shape or annular sector.

[0028] As shown in FIG. 1, in one embodiment, the split copper foil 21 is formed by 12 sectoral small copper foils 211 circumferentially arranged around the center of the second director 2 at intervals. In some other embodiments, the small copper foil 211 may also be other polygons, such as an annular sector. As shown in FIG. 3, the split copper foil 21 is constructed of 12 small copper foils 211 of sectoral shape arranged circumferentially around the center of the second director 2 at intervals. Of course, the split copper foil 21 may also be formed by circumferentially arranging 4 small copper foils 211 of a sectoral shape around the center of the second director 2 at intervals. Here, the radius of each small sectoral copper foil 211 is smaller than 0.25λ, where λ is the wavelength of the center frequency of the antenna.

[0029] As shown in FIG. 4, a second aspect of this embodiment proposes a multi-frequency base station antenna array. The multi-frequency base station antenna array includes a reflector and a high-frequency array and a low-frequency array arranged on the reflector. The high-frequency array includes several high-frequency radiation units 3, and the low-frequency array includes several low-frequency radiation units 4. Here, two rows of the high-frequency arrays and low-frequency arrays are provided, and a corresponding high-frequency radiation unit 3 is distributed below a corresponding low-frequency radiation unit 4. The multi-frequency base station antenna array also includes a double-layered director described in the above embodiments, and the double-layered director is arranged directly above a corresponding high-frequency radiation unit 3.

[0030] In order to fully demonstrate the effectiveness of the split director of the present invention, FIG. 5 shows comparison width change curves of the horizontal plane half-power beamwidth of the array antenna that adds two layers of prior art metal directors of the same size and the double-layered director of the present invention. It can be seen from FIG. 5 that after adding the split director of the present invention, the half-power beamwidth in the working frequency band of the antenna is more convergent, and the more the number of lobes, the more convergent the half-power beamwidth in the working frequency band. This is due to the introduction of the split director, which not only avoids the influence of the resonance of the director on the antenna high-frequency array itself, but also reduces the coupling and mutual interference between the high and low frequency radiation units, thus avoiding the superposition of scattered waves which otherwise will cause the pattern distortion.

[0031] The beneficial effects of the embodiments of the present invention are: the present invention produces multiple effects simultaneously by disposing the split copper foils 211 on the dielectric substrate 22. This not only weakens the influence of the resonant current of the director on the high-frequency radiation unit 3 itself, but also simplifies the boundary of the radiation unit, and reduces the coupling and mutual interference between the high-frequency and low-frequency radiation units, and avoids the superposition of scattered waves which otherwise will cause the pattern distortion. This in turn enables the multi-frequency base station antenna to have consistent and stable horizontal half-power lobe width and gain within the operating frequency band.

[0032] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the range described in this specification.

[0033] The above-mentioned embodiments only express the specific implementation manners of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.


Claims

1. A double-layered director, wherein the double-layered director includes a first director and a second director installed above the first director, and the second director includes a dielectric substrate and a split copper foil installed on the dielectric substrate.
 
2. The double-layered director according to claim 1, wherein the split copper foil includes a plurality of small copper foils, and the plurality of small copper foils are circumferentially arranged at intervals around a center of the second director.
 
3. The double-layered director according to claim 2, wherein the number of the small copper foils is at least 4.
 
4. The double-layered director according to claim 2, wherein the number of the small copper foils is at least 12.
 
5. The double-layered director according to claim 2, wherein the length of the small copper foils is less than 0.25λ, where λ is the wavelength of the center frequency of the antenna.
 
6. The double-layered director according to any one of claims 2-5, wherein the small copper foils are of a sector or annular sectoral shape.
 
7. The double-layered director according to any one of claims 1-5, wherein the first director is made of a whole piece of metal sheet.
 
8. The double-layered director according to claim 7, wherein the shape of the metal sheet is circular or polygonal.
 
9. A multi-frequency base station antenna array, wherein it includes a reflector and a high-frequency array and a low-frequency array arranged on the reflector, the high-frequency array includes several high-frequency radiation units, and the low-frequency array includes several low-frequency radiation units, each high-frequency radiation unit is distributed below a corresponding low-frequency radiation unit, and a double-layered director according to any one of claims 1-8 is also arranged directly above a corresponding high-frequency radiation unit.
 
10. The multi-frequency base station antenna array according to claim 9, wherein the number of the high-frequency array and the low-frequency array is two rows.
 




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