Multibeam antenna

Abstract

This invention provides a multi-beam antenna, including a reflector and an antenna array disposed on the reflector. The antenna array is composed of a mixture of various subarrays, each subarray consisting of a uniform array of multiple radiating elements. The types, quantities, and / or spacing of the radiating elements in different types of subarrays vary. Therefore, this invention overcomes the defect of horizontal misalignment of radiating elements, i.e., it solves the problem that the phase difference in the three-dimensional radiation pattern of the radiating elements in space leads to a decrease in the vertical downtilt accuracy and sidelobes of the antenna, resulting in increased neighboring interference and coverage holes. Simultaneously, it also possesses the advantages of horizontal misalignment of radiating elements, i.e., lower horizontal sidelobes to control neighboring interference between beams in the short-range area.

Description

Technical Field

[0001] This invention relates to the field of mobile communication base station antenna technology, and in particular to a multi-beam antenna. Background Technology

[0002] With the advent of the 5G era, 2G, 3G, and 4G networks will continue to coexist for a long time. Spectrum utilization, rooftop sharing, and antenna integration will become major challenges in the field of base station antennas. Multi-beam antennas can improve network coverage and capacity without requiring additional spectrum or rooftop space. For example, dual-beam antennas can increase capacity by approximately 1.7 times, and triple-beam antennas can increase capacity by approximately 2.2 times. Therefore, multi-beam antennas are increasingly favored by the market.

[0003] Figure 1 The diagram shows an embodiment of a first type of existing multi-beam antenna. All subarrays of the antenna are identical, uniformly arranged in the horizontal and vertical directions, with no misalignment in any direction. The radiation patterns corresponding to each subarray are approximately the same, meaning that the field distribution in space is roughly the same, with peaks coinciding and troughs coinciding. For example, the radiation pattern corresponding to the subarray composed of radiating elements 2-5-1, 2-5-2, 2-5-3, and 2-5-4 on reflector 1 is approximately the same as the radiation pattern corresponding to the subarray composed of radiating elements 2-6-1, 2-6-2, 2-6-3, and 2-6-4.

[0004] The power ratio between the subarray elements of the antenna is variable and the phase difference is constant. However, since the radiation patterns corresponding to each subarray are roughly the same, that is, the field distribution in space is roughly the same, with peaks coinciding with peaks and troughs coinciding with troughs, the synthesized antenna radiation pattern has a horizontal sidelobe difference of, for example, 8-9 dB, which seriously interferes with neighboring areas.

[0005] The close proximity of the antenna's subarray radiating elements leads to severe mutual coupling, poor antenna isolation, and difficulty in debugging.

[0006] Furthermore, for the 1710-2690MHz frequency band, when the power ratio between the subarray radiating elements of the antenna is small, the first sidelobe in the horizontal plane at 1710MHz is poor and the horizontal bandwidth is small; when the power ratio between the subarray radiating elements of the antenna is large, the second sidelobe in the horizontal plane at 2690MHz is poor and the horizontal bandwidth is large. Therefore, simply relying on the shaping design cannot solve the contradiction between these two factors well, and the horizontal bandwidth is often too divergent, for example, 23-43°.

[0007] Figure 2The following is an embodiment of a second type of existing multi-beam antenna. All subarrays of the antenna are identical, uniformly arranged in the horizontal and vertical directions, with only a half-spacing offset in the vertical direction. The horizontal radiation patterns corresponding to each subarray are roughly the same, meaning that the field distribution in space is roughly the same, with peaks coinciding and troughs coinciding. For example, the radiation pattern of the subarray composed of radiating elements 2-5-1, 2-5-2, 2-5-3, and 2-5-4 on reflector 1 is roughly the same as the radiation pattern of the subarray composed of radiating elements 2-6-1, 2-6-2, 2-6-3, and 2-6-4.

[0008] and Figure 1 Compared to the multi-beam antenna shown, after shifting the subarray vertically by half the array spacing, the distance between the radiating elements increases, mutual coupling decreases, and isolation is improved, but the performance defects of the horizontal plane radiation pattern remain unchanged.

[0009] Figure 3 The following is an embodiment of a third type of existing multi-beam antenna. All subarrays of the antenna are identical, only misaligned in the horizontal direction, and uniformly arranged in the vertical direction. Each subarray corresponds to a different horizontal plane radiation pattern, that is, the field distribution in space is different. The peaks no longer coincide with each other, and the troughs no longer coincide with each other. For example, the horizontal plane radiation pattern of the subarray composed of radiating elements 2-5-1, 2-5-2, 2-5-3, and 2-5-4 on the reflector 1 is different from the horizontal plane radiation pattern of the subarray composed of radiating elements 2-6-1, 2-6-2, 2-6-3, and 2-6-4.

[0010] and Figure 1 Compared to the multi-beam antenna shown, the horizontal plane radiation patterns corresponding to the sub-arrays of the antenna are different, meaning their field distributions in space are different. The peaks no longer coincide with each other, and the troughs no longer coincide with each other. Therefore, the sidelobes of the synthesized antenna pattern in the horizontal plane are suppressed, thereby reducing neighboring-area interference between beams in the short range. However, the horizontal misalignment of the sub-array radiating elements also causes a phase difference in the three-dimensional radiation patterns of the corresponding radiating elements in space. This leads to a deterioration in the antenna's vertical downtilt accuracy and sidelobes, and an increase in related neighboring-area interference and coverage holes.

[0011] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Summary of the Invention

[0012] To address the aforementioned shortcomings, the present invention aims to provide a multi-beam antenna that overcomes the defect of horizontal misalignment of the radiating elements. This solves the problem that the phase difference in the three-dimensional radiation pattern of the radiating elements in space leads to a decrease in the vertical tilt accuracy and sidelobes of the antenna, resulting in increased neighboring interference and coverage holes. At the same time, it also has the advantages of horizontal misalignment of the radiating elements, namely, a lower horizontal sidelobes to control neighboring interference between beams in the short range.

[0013] To achieve the above objectives, the present invention provides a multi-beam antenna, including a reflector and an antenna array disposed on the reflector. The antenna array is composed of a mixture of various subarrays, and each subarray is composed of a plurality of radiating elements uniformly arranged. The types, quantities and / or spacing of the radiating elements in the different types of subarrays are different.

[0014] According to the multi-beam antenna of the present invention, multiple subarrays are mixed and arrayed along the vertical direction of the reflector, and all subarrays are centered and aligned along the horizontal direction of the reflector.

[0015] According to the multi-beam antenna of the present invention, the number of subarrays in the antenna array is greater than or equal to 5.

[0016] According to the multi-beam antenna of the present invention, the number of radiating elements in each subarray is greater than or equal to 3.

[0017] According to the multi-beam antenna of the present invention, the distance between adjacent radiating elements in each subarray is 0.5 to 0.6 wavelengths of the center frequency.

[0018] According to the multi-beam antenna of the present invention, the distance between adjacent subarrays in the antenna array is 0.6 to 0.8 wavelengths of the center frequency.

[0019] According to the multi-beam antenna of the present invention, the antenna array is composed of a first seed array and a second seed array, wherein the type, number and / or spacing of the radiating elements in the first seed array and the second seed array are different.

[0020] According to the multi-beam antenna of the present invention, the number of radiating elements in the first seed array is 4, and the number of radiating elements in the second seed array is 3; the antenna array is composed of 9 mixed arrays of the first seed array and the second seed array, wherein the first to third subarrays are the first seed arrays, the fourth to seventh subarrays are the second seed arrays, and the eighth to ninth subarrays are the first seed arrays.

[0021] According to the multi-beam antenna of the present invention, the antenna array is composed of a first seed array, a second seed array, a third seed array and a fourth seed array, wherein the types, quantities and / or spacing of the radiating elements in the first seed array, the second seed array, the third seed array and the fourth seed array are different.

[0022] According to the multi-beam antenna of the present invention, the number of radiating elements in the first seed array, the second seed array and the fourth seed array is 4, and the number of radiating elements in the third seed array is 3; the first and second subarrays are the first seed array, the third and fourth subarrays are the second seed array, the fifth and tenth subarrays are the third seed array, and the eleventh and twelfth subarrays are the fourth seed array.

[0023] This invention relates to a multi-beam antenna composed of multiple subarrays of different types arranged in a specific order on a reflector. At least one of the following three factors differs: the type, number, and / or spacing of the radiating elements in each subarray. The three-dimensional radiation patterns of different subarrays differ in spatial orientation, shape, null position, and field strength. This results in a significant reduction in the sidelobes of the synthesized array beam in the horizontal plane (below the horizontal plane), thereby reducing neighboring interference between beams in close-range areas. This achieves the advantages of horizontal misalignment of the radiating elements while also converging the horizontal beamwidth to a certain extent. Simultaneously, it avoids the degradation of antenna vertical tilt accuracy, sidelobes, and the increase in neighboring interference and coverage holes caused by horizontal misalignment of the radiating elements, thus overcoming the defects of horizontal misalignment of the radiating elements. Preferably, all subarrays are centered and aligned along the horizontal direction of the reflector, which simplifies the overall spatial layout and reduces antenna weight by decreasing the number of radiating elements. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the first type of existing multi-beam antenna;

[0025] Figure 2 This is a schematic diagram of the second type of existing multi-beam antenna;

[0026] Figure 3 This is a schematic diagram of the third type of existing multi-beam antenna;

[0027] Figure 4 This is a schematic diagram of a first preferred embodiment of the multi-beam antenna of the present invention;

[0028] Figure 5 This is a horizontal plane radiation pattern of the subarray in a first preferred embodiment of the multi-beam antenna of the present invention;

[0029] Figure 6This is a schematic diagram of a second preferred embodiment of the multi-beam antenna of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0031] It should be noted that references to "an embodiment," "embodiment," "example embodiment," etc., in this specification refer to the described embodiment including specific features, structures, or characteristics, but not every embodiment must include these specific features, structures, or characteristics. Furthermore, such expressions do not refer to the same embodiment. Moreover, when describing specific features, structures, or characteristics in conjunction with embodiments, whether or not explicitly described, it is indicated that incorporating such features, structures, or characteristics into other embodiments is within the knowledge of those skilled in the art.

[0032] Furthermore, certain terms are used in the specification and subsequent claims to refer to specific components or parts. Those skilled in the art will understand that manufacturers may use different names or terms to refer to the same component or part. This specification and subsequent claims do not distinguish components or parts by differences in name, but rather by differences in function. The terms "comprising" and "including" used throughout the specification and subsequent claims are open-ended and should be interpreted as "including but not limited to." Additionally, the term "connection" here includes any direct and indirect electrical connection means. Indirect electrical connection means include connections made through other means.

[0033] This invention provides a multi-beam antenna, including a reflector and an antenna array disposed on the reflector. The antenna array is composed of a mixture of various subarrays. Each subarray is composed of multiple uniformly arranged radiating elements; the types, numbers, and / or spacing of the radiating elements in different types of subarrays are different. The number of subarray types in the multi-beam antenna is N, where N is greater than or equal to 2, for example, 2, 3, 4, 5, etc. Because the radiation patterns of different types of subarrays in the multi-beam antenna have different field distributions in space, the corresponding peak and trough positions are also different, and the horizontal plane radiation patterns are also different. Therefore, the sidelobes of the synthesized antenna radiation pattern in the horizontal plane are suppressed, and the neighboring area interference between beams in the close range is reduced accordingly. In addition, through the design of different subarray combinations, this invention reduces the bandwidth range of the radiation pattern synthesized by superimposing all subarrays in the horizontal plane, while avoiding the problems of reduced antenna vertical tilt accuracy and sidelobes caused by horizontal misalignment of the radiating elements in the subarrays.

[0034] Preferably, multiple subarrays are mixed and arrayed along the vertical direction of the reflector, and all subarrays are centered and aligned along the horizontal direction of the reflector. This helps to simplify the overall spatial layout and also reduces the antenna weight by reducing the number of radiating elements.

[0035] Preferably, the number of subarrays in the antenna array is greater than or equal to 5. The distance between adjacent subarrays in the antenna array is 0.6 to 0.8 wavelengths of the center frequency.

[0036] Preferably, the number of radiating elements in each subarray is greater than or equal to 3. The distance between adjacent radiating elements in each subarray is 0.5 to 0.6 wavelengths of the center frequency.

[0037] Reference Figure 4 In the preferred embodiment shown, the multi-beam antenna includes: M sub-arrays that are mixed and arrayed along the vertical direction of the reflector, all sub-arrays being centered and aligned along the horizontal direction of the reflector, the number of the first seed array being M1, the number of the second seed array being M2, ..., M1+M2+...=M, M1 is greater than or equal to 1, M2 is greater than or equal to 1, ..., M is greater than or equal to 5.

[0038] The first subarray consists of A1 radiating elements arranged uniformly with horizontal spacing of H1-1, H1-2…, where H1 is 0.5-0.6 wavelengths of the center frequency, and A1 is greater than or equal to 3. The vertical spacing between the first subarray and its adjacent subarray on the right is V1, where V1 is 0.6-0.8 wavelengths of the center frequency. The corresponding radiating elements are numbered 2-1-1, 2-1-2, 2-1-3…

[0039] The second subarray consists of A2 radiating elements arranged uniformly with horizontal spacing of H2-1, H2-2…, where H2 is 0.5-0.6 wavelengths of the center frequency, and A2 is greater than or equal to 3. The vertical spacing between the second subarray and the adjacent subarray on the right is V2, where V2 is 0.6-0.8 wavelengths of the center frequency. The corresponding radiating elements are numbered 2-2-1, 2-2-2, 2-2-3…

[0040] ...

[0041] And so on.

[0042] Preferably, the antenna array of the present invention is composed of a hybrid array of a first seed array and a second seed array, wherein the types, quantities and / or spacing of the radiating elements in the first seed array and the second seed array are different.

[0043] Figure 4This is a schematic diagram of a first preferred embodiment of the multi-beam antenna of the present invention. The first seed array of the multi-beam antenna has 4 radiating elements, the second seed array has 3 radiating elements, the 1st, 2nd, 3rd, 8th and 9th subarrays are the first seed arrays, and the 4th, 5th, 6th and 7th subarrays are the second seed arrays.

[0044] The radiation patterns of the first and second subarrays of the antenna have different field distributions in space, corresponding to different peak and trough positions, and also different horizontal plane radiation patterns. For example, the horizontal plane radiation pattern of the subarray composed of radiating elements 2-3-1, 2-3-2, 2-3-3, and 2-3-4 on reflector 1 is different from the horizontal plane radiation pattern of the subarray composed of radiating elements 2-5-1, 2-5-2, and 2-5-3. Figure 5 As shown, the sidelobes of the synthesized antenna pattern are suppressed in the horizontal plane, thus reducing neighboring-cell interference between beams in the close-range range. Simultaneously, since all subarrays are uniformly arrayed and centered, the downtilt accuracy and sidelobes of the synthesized pattern in the vertical plane are comparable to those of conventional antennas. Furthermore, through different subarray combination designs, the bandwidth of the synthesized pattern in the horizontal plane is reduced, for example, converging to 27-38° in the 1710-2170MHz band, resulting in more concentrated energy and better coverage.

[0045] Preferably, the antenna array is composed of a mixture of a first seed array, a second seed array, a third seed array, and a fourth seed array, wherein the types, quantities, and / or spacing of the radiating elements in the first seed array, the second seed array, the third seed array, and the fourth seed array are different.

[0046] Figure 6 This is a schematic diagram of a second preferred embodiment of the multi-beam antenna of the present invention. The number of radiating elements in the first seed array, the second seed array, and the fourth seed array is 4, and the number of radiating elements in the third seed array is 3. The first and second subarrays are the first seed array, the third and fourth subarrays are the second seed array, the fifth and tenth subarrays are the third seed array, and the eleventh and twelfth subarrays are the fourth seed array.

[0047] The radiation patterns of the first, second, third, and fourth subarrays of the antenna have different field distributions in space, corresponding to different peak and trough positions, and different horizontal plane radiation patterns. For example, the horizontal plane radiation pattern of the subarray composed of radiating elements 2-3-1, 2-3-2, 2-3-3, and 2-3-4 on reflector 1 is different from the horizontal plane radiation pattern of the subarray composed of radiating elements 2-5-1, 2-5-2, and 2-5-3. Figure 6As shown, the sidelobes of the radiation pattern synthesized by superimposing all subarrays are suppressed in the horizontal plane, and the interference between beams in adjacent areas at close range is reduced. Simultaneously, since all subarrays are uniformly arrayed and centrally aligned, the downtilt accuracy and sidelobes of the radiation pattern synthesized by superimposing all subarrays are comparable to those of conventional antennas in the vertical plane. Furthermore, through different subarray combination designs, the bandwidth of the radiation pattern synthesized by superimposing all subarrays is reduced in the horizontal plane, for example, converging to 25-41° in the 1710-2690MHz band, resulting in more concentrated energy and better coverage.

[0048] In summary, the multi-beam antenna of this invention is composed of multiple sub-arrays of different types arranged in a specific order on a reflector. At least one of the following three factors—the type, number, and / or spacing of the radiating elements in the different sub-arrays—is different. The three-dimensional radiation patterns of different sub-arrays differ in spatial orientation, shape, null position, and field strength. This significantly reduces the sidelobes of the synthesized array beam in the horizontal plane (i.e., the sidelobes below the horizontal plane), thereby reducing neighboring interference between beams in the short-range area. This achieves the advantage of horizontal misalignment of the radiating elements. The horizontal beamwidth also converges to a certain extent, while avoiding the degradation of antenna vertical tilt accuracy, sidelobes, and the increase in neighboring interference and coverage holes caused by horizontal misalignment of the radiating elements. This overcomes the defects of horizontal misalignment of the radiating elements. Preferably, all sub-arrays are centered and aligned along the horizontal direction of the reflector, which simplifies the overall spatial layout and reduces antenna weight by decreasing the number of radiating elements.

[0049] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A multi-beam antenna, characterized in that, It includes a reflector and an antenna array disposed on the reflector. The antenna array is composed of a mixture of multiple subarrays, and each subarray is composed of multiple radiating elements uniformly arranged. The types and / or spacing of the radiating elements in the different types of subarrays are different. The various subarrays are mixed and arrayed along the vertical direction of the reflector, and all the subarrays are centered and aligned along the horizontal direction of the reflector. The number of radiating elements in each of the subarrays is greater than or equal to 3.

2. The multi-beam antenna according to claim 1, characterized in that, The number of subarrays in the antenna array is greater than or equal to 5.

3. The multi-beam antenna according to claim 1, characterized in that, The distance between adjacent radiating elements in each subarray is 0.5 to 0.6 wavelengths of the center frequency.

4. The multi-beam antenna according to claim 1, characterized in that, The distance between adjacent subarrays in the antenna array is 0.6 to 0.8 wavelengths of the center frequency.

5. The multi-beam antenna according to claim 1, characterized in that, The antenna array is composed of a first seed array and a second seed array, wherein the types and / or spacing of the radiating elements in the first seed array and the second seed array are different.

6. The multi-beam antenna according to claim 1, characterized in that, The antenna array is composed of a mixed array of a first seed array, a second seed array, a third seed array, and a fourth seed array, wherein the types and / or spacing of the radiating elements in the first seed array, the second seed array, the third seed array, and the fourth seed array are different.

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