Antenna array

Abstract

The invention discloses an antenna array, which comprises a reflecting plate, a feed network and a plurality of discontinuous broadband arrays with different working frequency bands, the feed network is connected with the broadband array; the broadband array comprises a plurality of continuous narrow-band arrays with different working frequency bands, and each narrow-band array comprises a plurality of antenna units with the same working frequency band; through the structure, the layout of the antenna array is simple and more compact, the broadband antenna array is split into a plurality of narrow-band antenna arrays working in different but continuous frequency bands, the quality factor of each sub-frequency band can be improved, the level of an array generation directional diagram is effectively ensured, the wave width and the gain are kept stable in the full frequency band, and the antenna array is more compact in structure. And the external influence and the multipath effect are effectively overcome, and errors caused by the influence of external factors are avoided.

Description

Technical Field

[0001] The present invention relates to the field of base station antennas, and in particular to an antenna array. Background Art

[0002] With the rapid development of mobile communication technology and increasingly fierce competition in the communication industry, suppliers have increasingly wider requirements for base station antenna operating frequency bands, among which the most commonly used are 3G / 4G / 5G commercial frequency bands operating at 0.61-0.96GHz, 1.4-2.7GHz, and 3.3-3.8GHz. Traditional base station antenna units need to keep their array patterns normal and highly consistent within the above ultra-wide frequency bands. However, as the continuous operating frequency bands become wider and wider, the antenna's full-band comprehensive quality factor will become lower and lower, and the pattern will have increasingly obvious distortion in the upper / lower sidebands, resulting in the generated array pattern having poor robustness within the entire operating frequency band, leaving a large room for optimization. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an antenna array.

[0004] A technical solution adopted by an embodiment of the present invention to solve its technical problem is: an antenna array, including a reflector, a feeding network, and several broadband arrays with different and discontinuous working frequency bands; the feeding network is connected to the broadband array; the broadband array includes several narrowband arrays with different but continuous working frequency bands, and each narrowband array includes several antenna units with the same working frequency band.

[0005] As one of the preferred embodiments of the present invention, different narrowband arrays in the broadband array and / or the antenna units contained therein are arranged in a staggered order on the reflector.

[0006] As one of the preferred embodiments of the present invention, the broadband array includes several unit groups, the unit group includes at least one antenna unit in each narrowband array, and the antenna units with the same working frequency band in different unit groups constitute the narrowband array.

[0007] As one of the preferred embodiments of the present invention, in the unit group, at least one antenna unit with the highest working frequency band in the broadband array is arranged between two adjacent antenna units.

[0008] As one of the preferred embodiments of the present invention, in the unit group, an antenna unit with the highest operating frequency band in the broadband array is coaxially arranged above the antenna unit.

[0009] As one of the preferred embodiments of the present invention, the feeding network includes a plurality of first phase shifters and a plurality of first combiners, and the narrowband array is connected to the first combiners via the first phase shifters to form a broadband array.

[0010] As one of the preferred embodiments of the present invention, the feeding network includes a plurality of second phase shifters and a plurality of second combiners, and the narrowband array is connected to the second phase shifters via the second combiners to form a broadband array.

[0011] The beneficial effects of the present invention are as follows: an antenna array comprises a reflector, a feeding network and a plurality of broadband arrays with different and discontinuous working frequency bands; the feeding network is connected to the broadband array; the broadband array comprises a plurality of narrowband arrays with different but continuous working frequency bands, and each narrowband array comprises a plurality of antenna units with the same working frequency band; the above structure can simplify the layout of the antenna array and make it more compact, and split the broadband antenna array into a plurality of narrowband antenna arrays working in different but continuous frequency bands, so as to improve the quality factor of each sub-band, effectively ensure the level of the array-generated radiation pattern, ensure that the wavelength and gain remain stable in the whole frequency band, and effectively overcome the external influence and multipath effect, and avoid the error caused by the influence of external factors. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0013] Figure 1 Schematic diagram of the antenna array in the original scheme;

[0014] Figure 2 The overall structure flow chart of the antenna array in the present invention;

[0015] Figure 3 A subdivision structure flow chart of the antenna array in the present invention;

[0016] Figure 4 is another subdivision structure flow chart of the antenna array in the present invention;

[0017] Figure 5 is a schematic structural diagram of a first embodiment of an antenna array in the present invention;

[0018] Figure 6 is a schematic structural diagram of a second embodiment of an antenna array in the present invention;

[0019] Figure 7 is a schematic structural diagram of a third embodiment of an antenna array in the present invention;

[0020] Figure 8 A comparison diagram of the horizontal plane half-power beam width between the first embodiment of the antenna array of the present invention and the antenna array in the original solution;

[0021] Fig. 9 4 is a gain comparison diagram of the first embodiment and the second embodiment of the antenna array in the present invention. DETAILED DESCRIPTION

[0022] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0023] In the description of the present invention, the meaning of "above", "below", "exceed", etc. is not inclusive of the number itself, and the meaning of "above", "below", "within", etc. is inclusive of the number itself. If there is a description of "first" or "second", it is only used to distinguish the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0024] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0025] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0026] In the present invention, the relationship between the impedance bandwidth BW and the quality factor Q can be expressed as:

[0027] Q=Z im / Z re =f0 / BW (1)

[0028] Among them, for the antenna radiation surface, the bandwidth BW of the antenna can be expressed as:

[0029] BW=16*((πr) 3 ) / (η*λ 3 ) (2)

[0030] Where r is the near field radius of the antenna unit, η is the radiation efficiency of the antenna, and λ is the operating wavelength of the antenna.

[0031] Since base station antennas usually operate in a wide frequency band, an intermediate value is needed to define the antenna's operating wavelength. Suppose the defined antenna operating frequency is F0, and the upper sideband of the antenna's operating frequency band is F H , the lower side frequency is F L ,but:

[0032]

[0033] The antenna operating frequency is obtained by equation (3), and then the corresponding wavelength is obtained. Then, the ideal bandwidth of the antenna can be obtained by substituting it into equation (2), and then the quality factor of the antenna can be obtained.

[0034] It can be seen from formula (2) that the higher the radiation efficiency η, the narrower the antenna bandwidth BW. The radiation efficiency here is only the radiation efficiency under ideal conditions. In practical applications, it is a component of the total radiation efficiency. Suppose the total radiation efficiency of the antenna is η a , then the relationship between it and the ideal radiation efficiency η can be expressed as follows:

[0035] η a =μ*μ i *η1*η2… (4)

[0036] Wherein, μ is the radiation efficiency of the antenna without considering external influences, which can be the radiation efficiency of the antenna unit obtained by simulation; μ i It is the aperture efficiency, μ1*μ2… includes various external influences on the antenna, such as illumination leakage, aperture obstruction, surface tolerance, depolarization loss, etc. All μ are factor values ​​between 0 and 1. Each additional factor means that it is more affected by external environmental interference, and the final antenna radiation efficiency is lower.

[0037] Total radiation efficiency η a There is a direct relationship with the gain. Assuming the antenna gain is G, then the gain G is related to the total radiation efficiency η a The relationship between can be expressed as follows:

[0038] G=(4π / λ 2 )*A*η a (5)

[0039] Among them, A is the coefficient factor brought by the specific structure of the antenna, which is usually expressed as the ratio of the radiation power of the ideal dipole and the designed antenna in the same electromagnetic environment.

[0040] It can be seen from formula (5) that, under the condition of certain wavelength and structure, the higher the radiation efficiency, the higher the gain; combining formulas (1)-(5), it can be concluded that: the higher the quality factor, the narrower the bandwidth, the higher the radiation efficiency, and the higher the gain; the radiation efficiency and gain of the array antenna in the overall frequency band can be improved by increasing the quality factor of the antenna array, and the gain value of the array antenna in the working frequency band can be kept stable, and the increase of the quality factor can be achieved by reducing the bandwidth of the antenna array. Based on this, the following formula is proposed:

[0041] Q=(Q1+ Q2+Q3+...+Q m ) / M (6)

[0042] Where Q is the quality factor of the entire antenna. The difference is that formula (6) divides the working frequency band of the antenna into M, where M is a natural number variable greater than 1. By calculating the quality factor Q of each frequency band M , then add them up and divide by the number of frequency bands to get the quality factor of the entire antenna operating frequency band.

[0043] Define the above antenna as A0, then antenna A0 is also divided into multiple narrowband sub-antennas like the quality factor of the antenna. Each narrowband sub-antenna has a different operating frequency band. The operating frequency bands of all narrowband sub-antennas combined together are exactly the operating frequency band of antenna A0; the narrowband antenna is called A M , then the narrowband antenna A M The working bandwidth is BW M , narrowband antenna A M The relationship between the working bandwidth of antenna A0 can be expressed as follows:

[0044] BW=BW1+ BW2+BW3+...+BW M (7)

[0045] If the radiation efficiency of antenna A0 is η, the narrowband antenna A M The radiation efficiency is η M , the relationship between the two is as follows:

[0046] η=(η1+ η2+η3+...+η M ) / M (8)

[0047] From formula (7), we can get that the narrowband antenna A M Each bandwidth of the antenna A0 is smaller than the bandwidth of the antenna A0 as a single antenna. Therefore, each narrowband antenna A M The quality factor Q and radiation efficiency η of the antenna A0 are higher than the quality factor Q and radiation efficiency η when the antenna A0 is used as a single antenna. M and η MThe calculated average value must also be greater than the quality factor Q and the radiation efficiency η when the antenna A0 is used as a single antenna.

[0048] 1)Reference Figure 1 , as a solution of the existing antenna array, includes a reflector 100 and two broadband arrays 300, each broadband array 300 includes a plurality of antenna units D with an operating frequency band of 1.4-2.7 GHz.

[0049] 2)Reference Figures 2 to 7 The present invention proposes an antenna array, including a reflector 100, a feeding network 200, and a plurality of broadband arrays 300 with different and discontinuous working frequency bands; the feeding network 200 is connected to the broadband array 300; the broadband array 300 includes a plurality of narrowband arrays 310 with different but continuous working frequency bands, and each narrowband array 310 includes a plurality of antenna units 311 with the same working frequency band.

[0050] Specifically, the antenna array has multiple antenna units which are arranged into several arrays on the reflector 100 and operate in N discontinuous wide frequency bands; each broadband array 300 is divided into M narrowband arrays 310 operating in different but continuous frequency bands, and each narrowband array 310 is composed of multiple antenna units 311 with the same operating frequency band, where N is a positive integer and M is a natural number greater than 1.

[0051] 3)Reference Figure 2-Figure 5 As a first embodiment of the antenna array of the present invention, different narrowband arrays 310 in the broadband array 300 and / or the antenna units 311 contained therein are arranged in a staggered order on the reflector 100. Specifically, the antenna array includes the reflector 100 and a plurality of antenna units 311A, antenna units 311B and antenna units 311C, and the antenna units are evenly arranged on the reflector in two columns; further, the antenna units 311A, antenna units 311B and antenna units 311C are respectively contained in the narrowband array 310A, the narrowband array 310B and the narrowband array 310C, and the array topologies of the narrowband arrays 310A, the narrowband array 310B and the narrowband array 310C in adjacent columns are in opposite order, and at the same time, each column of the narrowband arrays 310A and the narrowband arrays 310C are distributed on both sides of the narrowband array 310B.

[0052] In the array structure, the operating frequency band of the narrowband array 310C is 2.2-2.7 GHz, the operating frequency band of the narrowband array 310B is 1.7-2.2 GHz, and the operating frequency band of the narrowband array 310A is 1.4-1.7 GHz; the narrowband array 310A, the narrowband array 310B and the narrowband array 310C operate in different but continuous frequency bands, and all are narrow frequency bands. The narrower the operating frequency band, the higher the antenna quality factor; and then the three narrowband arrays are excited simultaneously to make the entire array operate at 1.4-2.7 GHz, so that the entire frequency band is in a state of relatively high quality factor, effectively ensuring that the bandwidth and gain of the array-generated radiation pattern remain stable over the entire frequency band.

[0053] contrast Figure 1 In the original solution, since the antenna units 311B of this embodiment are distributed in two columns, the antenna units 311A ​​and 311C are adjacent, and the working frequency band of the antenna unit 311C is the highest among the three antenna units, the required width of the reflector 100 is narrower. Therefore, the overall width of the array structure in the first embodiment is narrower, and the area used by the reflector 100 is smaller; further, compared Figure 1 The antenna unit D forms an array structure, and the frequency band of the antenna unit D is 1.4-2.7 GHz. In this embodiment, the same frequency band is divided into three antenna unit frequency bands of adjacent antenna units 311A, antenna units 311B and antenna units 311C. The final result of applying the two array structures is as follows: Figure 8 As shown, the new scheme of horizontal plane half-power beam width has better consistency within the working frequency band than the original scheme. The effect in this embodiment is better, more robust and more stable, which can improve the efficiency of the system and reduce transmission loss.

[0054] 4)Reference Figure 2-Figure 4 as well as Figure 6 As the second embodiment of the antenna array of the present invention, an improvement is made on the basis of the above-mentioned first embodiment. The broadband array 300 includes a plurality of unit groups 300a. The unit group 300a includes at least one antenna unit 311 in each narrowband array 310. The antenna units 311 with the same working frequency band in different unit groups 300a constitute the narrowband array 310. Furthermore, in the unit group 300a, between two adjacent antenna units 311, there is also an antenna unit 311 with the highest working frequency band in the broadband array 300.

[0055] Specifically, the antenna array includes a reflector 100 and a plurality of antenna units 311A, an antenna unit 311B and an antenna unit 311C, and the antenna units are evenly arranged in two columns on the reflector; further, the antenna unit 311A, the antenna unit 311B and the antenna unit 311C are respectively included in the narrowband array 310A, the narrowband array 310B and the narrowband array 310C, and a unit group 300a is formed by a group of four "antenna unit 311C, antenna unit 311B, antenna unit 311C and antenna unit 311A", and the small array form repeated multiple times is divided into two independent rows and arranged along a straight line on the reflector 100, so that the antenna unit 311A ​​is separated from the antenna unit 311B by the antenna unit 311C.

[0056] For example Figure 5 In the first embodiment shown in the figure, the same frequency band is divided into adjacent "antenna unit 311C, antenna unit 311B, antenna unit 311C and antenna unit 311A" array structures, the working frequency band of antenna unit 311C is 2.2-2.7 GHz, the working frequency band of antenna unit 311B is 1.7-2.2 GHz, and the working frequency band of antenna unit 311A ​​is 1.4-1.7 GHz; the final result of applying the two array structures of the first embodiment and the second embodiment is as follows Fig. 9 As shown, it can be seen that since the units of the second embodiment are more evenly distributed, the gain has better consistency and pitch angle within the working frequency band than the first embodiment, and the gain is increased within the working frequency band compared to the first embodiment, that is, the effect of the second embodiment is better; the structure in this embodiment is simple and easy to assemble, and multiple working frequencies can be used to receive signals, and the average is finally taken to avoid data distortion, and since the antenna units are independently distributed, antenna units of different heights can be used to receive signals in a diversity manner to ensure the stability of the generated directional pattern.

[0057] 5)Reference Figure 2-Figure 4 as well as Figure 7 As the third embodiment of the antenna array of the present invention, an improvement is made on the basis of the above-mentioned second embodiment. In the unit group 300a, the antenna unit 311 with the highest working frequency band in the broadband array 300 is coaxially arranged above the antenna unit 311.

[0058] Specifically, the antenna array includes a reflector 100 and a plurality of antenna units 311A, an antenna unit 311B and an antenna unit 311C, and the antenna units are evenly arranged on the reflector in two columns; further, the antenna unit 311A, the antenna unit 311B and the antenna unit 311C are respectively included in the narrowband array 310A, the narrowband array 310B and the narrowband array 310C, wherein the antenna unit 311A ​​and the antenna unit 311C have a coaxial structure to form an AC coaxial antenna unit, and the antenna unit 311C and the antenna unit 311B have a coaxial structure to form a BC coaxial antenna unit, and the AC coaxial antenna unit, the BC coaxial antenna unit and the antenna unit 311C are periodically and evenly distributed in the entire array; a subarray is formed by using "BC coaxial antenna unit, AC coaxial antenna unit and antenna unit 311C" as a group, and the subarray is arranged along Figure 7 The array extension direction is distributed periodically to form a large array, and then the large array is stretched out in K columns along a direction perpendicular to the array extension direction, where K is a positive integer, thereby forming a large-scale compact wide-band transceiver antenna array.

[0059] Due to the use of coaxial structure, space is saved, the reflector area is smaller, the cost is reduced, and the antenna is more compact, which can achieve multi-band coverage in a limited space; further, compared Figure 6 The second embodiment is shown, in which the same frequency band is divided into adjacent "BC coaxial antenna unit, AC coaxial antenna unit, antenna unit 311C" array structure, the working frequency band of antenna unit 311C is 2.2-2.7GHz, the working frequency band of antenna unit 311B is 1.7-2.2GHz, and the working frequency band of antenna unit 311A ​​is 1.4-1.7GHz. In this embodiment, BC coaxial antenna unit, AC coaxial antenna unit, and antenna unit 311C are used in a group of three, the height of the antenna unit is reduced, and the structure is more compact.

[0060] 6)Reference Figure 2-Figure 3 The feeding network 200 includes a plurality of first phase shifters 210 and a plurality of first combiners 220. The narrowband arrays 310 are connected to the first combiners 220 via the first phase shifters 210 to form a broadband array 300; that is, each narrowband array 310 is connected to a first phase shifter 210, and then connected to the first combiner 220 for combined output.

[0061] 7)Reference Figure 2 and Figure 4The feeding network 200 includes a plurality of second phase shifters 230 and a plurality of second combiners 240. The narrowband array 310 is connected to the second phase shifter 230 via the second combiner 240 to form a broadband array 300. The structural flow chart of the antenna array of the present invention is improved so that the narrowband array 310 is first combined by the second combiner 240 and then phase-shifted by the second phase shifter 230. This solution does not require a large number of phase shifters to be laid for each narrowband array 310, which is beneficial to reducing costs, link losses and signal mutual coupling between links.

[0062] 8) The advantages of the present invention are: the above structure can make the layout of the antenna array simple and more compact, and split the wide-band antenna array into multiple narrow-band antenna arrays working in different but continuous frequency bands, which can improve the quality factor of each sub-band, effectively ensure the level of the array-generated radiation pattern, ensure that the bandwidth and gain remain stable in the entire frequency band, and effectively overcome external influences and multipath effects, avoiding errors caused by external factors.

[0063] Of course, the present invention is not limited to the above-mentioned embodiments, and those skilled in the art may make equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications and substitutions are all included in the scope defined by the claims of this application.

Claims

1. An antenna array, characterized in that: The invention comprises a reflection plate (100), a feeding network (200), and a plurality of broadband arrays (300) having different and discontinuous working frequency bands; the feeding network (200) is connected to the broadband array (300); the broadband array (300) comprises a plurality of narrowband arrays (310) having different but continuous working frequency bands, and each narrowband array (310) comprises a plurality of antenna units (311) having the same working frequency band.

2. The antenna array according to claim 1, characterized in that: The different narrowband arrays (310) in the broadband array (300) and / or the antenna units (311) contained therein are arranged in a staggered order on the reflection plate (100).

3. The antenna array according to claim 1, characterized in that: The broadband array (300) comprises a plurality of unit groups (300a), wherein the unit group (300a) comprises at least one antenna unit (311) in each narrowband array (310), and the antenna units (311) with the same operating frequency band in different unit groups (300a) constitute the narrowband array (310).

4. The antenna array according to claim 3, characterized in that: In the unit group (300a), at least one antenna unit (311) with the highest operating frequency band in the broadband array (300) is arranged between two adjacent antenna units (311).

5. The antenna array according to claim 3, characterized in that: In the unit group (300a), the antenna unit (311) with the highest operating frequency band in the broadband array (300) is coaxially arranged above the antenna unit (311).

6. The antenna array according to claim 1, characterized in that: The feeding network (200) comprises a plurality of first phase shifters (210) and a plurality of first combiners (220); the narrowband array (310) is connected to the first combiners (220) via the first phase shifters (210) to form the broadband array (300).

7. The antenna array according to claim 1, characterized in that: The feeding network (200) comprises a plurality of second phase shifters (230) and a plurality of second combiners (240); the narrowband array (310) is connected to the second phase shifters (230) via the second combiners (240) to form the broadband array (300).

Images