A broadband nine-beam array antenna

Abstract

The present invention relates to the field of communication antenna technology, and specifically to a broadband nine-beam array antenna. The present invention includes a metal reflector, a radiation unit array, a beamforming network, a first power divider network, a second power divider network and a phase compensation circuit; the radiation unit array is connected to the second power divider network and fixedly installed on the metal reflector, and the beamforming network is connected to the first power divider network through the phase compensation circuit and fixedly installed on the metal reflector. The present invention has good sidelobe and grating lobe suppression performance in an ultra-wide frequency band, reducing the neighboring cell interference of the cell corresponding to the beam. Compared with the five-beam antenna, the nine-beam antenna of the present invention realizes more cell splitting in the same spatial range, realizes frequency reuse of more adjacent cells without increasing the antenna site, and further improves the network capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of communication antennas, and in particular to a broadband nine-beam array antenna. Background Art

[0002] After the fourth generation of mobile communication technology 4G / LTE was put into commercial use on a large scale, the data traffic in the mobile communication network surged, and the bandwidth capacity of the mobile communication system in densely populated areas faced tremendous pressure. To address the problem of limited capacity of a single cell, a multi-beam antenna is used. The coverage area of ​​a conventional single sector can be subdivided into multiple sectors, and the wireless channel capacity is increased exponentially. The invention patent with publication number CN102570057A proposes a method of using a 6×6 Butler matrix to generate five beams, such as Figure 2 As shown. Each column of evenly arranged radiating units is connected to a vertical power divider, and then to a 6×6 Butler matrix output port. Each polarization corresponds to a 6×6 Butler matrix. However, the operating bandwidth of this technology is only 23.7% (1710-2170MHz), and it is not compatible with the 2300 and 2600MHz bands of 4G LTE at the same time. If the frequency band is widened to the 1700-2700MHz band, the 2700MHz frequency in the azimuth plane will produce a very high grating lobe of about -5dB, which will cause great interference to adjacent cells. Patent 201621038190.7 uses a horizontally staggered arrangement of radiating units to achieve better grating lobe suppression capabilities.

[0003] Sports stadiums gather tens of thousands or even 100,000 mobile communication users at occasions such as the opening ceremony of the Olympic Games. Using five beams for cell splitting is still not enough to cope with the growing traffic demand. Therefore, in order to further increase capacity, it is necessary to design base station antennas with more beams, and at the same time widen the working frequency band to 1427-2700MHz, compatible with the current mobile communication 4G / 3G standard frequency band and the 2G standard frequency band, and reserve the needs of future upgrades, and have good sidelobe and grating lobe suppression performance in the azimuth direction within the working frequency band to overcome the above problems. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, it is necessary to propose a broadband nine-beam array antenna with higher capacity for network coverage in some special scenarios, such as sports stadiums and performance centers with very dense mobile communications. The present invention proposes a broadband nine-beam array antenna, including a metal reflector, a radiation element array, a beamforming network, a first power divider network, a second power divider network and a phase compensation circuit;

[0005] The radiation unit array is connected to the second power divider network and fixedly mounted on the metal reflector; the beam forming network is connected to the first power divider network through the phase compensation circuit and fixedly mounted on the metal reflector;

[0006] The radiation unit array includes more than or equal to 2 radiation unit groups, each of the radiation unit groups is arranged in the horizontal direction, and at least one radiation unit group is offset in the horizontal direction;

[0007] The radiation unit group includes greater than or equal to 12 radiation units;

[0008] There are at least two beamforming networks, each of which includes a 12-way Butler matrix circuit and a 2-way power divider group;

[0009] There are at least eight phase compensation circuits, and each of the phase compensation circuits includes two independent transmission lines.

[0010] Furthermore, the number of the radiation unit groups is 6, and the radiation units are dual-polarization antenna units.

[0011] Furthermore, adjacent rows of the radiation element array are arranged in a horizontally offset manner.

[0012] Further, the first power splitter network comprises at least 8 2-way power splitter circuits, and the input port of the first power splitter network is the input port of the antenna;

[0013] The second power divider network includes at least 24 3-way power divider circuits; the output port of the 3-way power divider circuit is connected to three radiating units located at the same horizontal position in different rows, and the input port of the 3-way power divider circuit is connected to the output port of the beamforming network.

[0014] Furthermore, each of the 12-way Butler matrix circuits includes 4 3×3 Butler matrix circuits, 3 4×4 Butler matrix circuits and 9 phase shifters; the 3×3 Butler matrix circuit and the 4×4 Butler matrix circuit are cross-connected through the phase shifters.

[0015] Furthermore, each of the 12-way Butler matrix circuits includes 12 input ports isolated from each other and 12 output ports isolated from each other, wherein three input ports are connected to a 50-ohm load and grounded, and the remaining input ports serve as nine input ports of a beamforming network, namely, a first input port, a second input port, a third input port, a fourth input port, a fifth input port, a sixth input port, a seventh input port, an eighth input port and a ninth input port, and correspond to a first beam, a second beam, a third beam, a fourth beam, a fifth beam, a sixth beam, a seventh beam, an eighth beam and a ninth beam, respectively.

[0016] Further, the azimuth range of the first beam is 25 to 50 degrees, the azimuth range of the second beam is 18 to 35 degrees, the azimuth range of the third beam is 10 to 25 degrees, the azimuth range of the fourth beam is 5 to 15 degrees, the azimuth range of the fifth beam is 0 degree, the azimuth range of the sixth beam is -5 to -15 degrees, the azimuth range of the seventh beam is -10 to -25 degrees, the azimuth range of the eighth beam is -18 to -35 degrees, and the azimuth range of the ninth beam is -25 to -50 degrees.

[0017] Furthermore, the phase difference between the two independent transmission lines is in the range of 0 degree to 90 degrees.

[0018] Further, the horizontal spacings of the radiation units in the radiation unit group are equal, and the vertical spacings between the radiation unit groups are equal;

[0019] The spacing is 0.4 to 0.95 times the wavelength of the center frequency of the array antenna operating frequency band;

[0020] The horizontal offset distance of each row of radiation elements is half of the horizontal distance of the radiation elements.

[0021] Furthermore, the first input port, the second input port, the third input port, the fourth input port, the sixth input port, the seventh input port, the eighth input port, and the ninth input port of the beamforming network are connected to the first power divider network through the phase compensation circuit.

[0022] Furthermore, the antenna operates in a frequency band of 1427-2700 MHz.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention provides a broadband nine-beam array antenna, each radiating unit group includes multiple radiating units arranged in the horizontal direction, at least one radiating unit group is offset in the horizontal direction, and multiple phase compensation circuits are used to perform phase compensation on the radiating unit group offset in the horizontal direction. In this way, the radiating units in different rows are arranged in a certain regular offset in the horizontal direction, and a certain phase compensation is added to the offset radiating units in the feeding network. The nine-beam antenna has good sidelobe and grating lobe suppression performance in the ultra-wide frequency band, reducing the interference of neighboring cells corresponding to the beam. At the same time, a 12-way Butler matrix circuit is used to realize a beamforming network that can generate nine beams in the azimuth direction. Compared with the five-beam antenna, the nine-beam antenna of the present invention realizes more cell splitting in the same spatial range, and realizes frequency reuse of more adjacent cells without increasing the antenna site, further improving the network capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 The radiation unit arrangement scheme of the broadband nine-beam antenna of the present invention;

[0027] Figure 2 A radiation element arrangement scheme for producing a five-beam antenna for the prior art;

[0028] Figure 3 It is a connection diagram of the radiation unit and the 3-way power divider circuit of the present invention;

[0029] Figure 4 A connection diagram of a beamforming network of the present invention;

[0030] Figure 5 : is an internal structure diagram of the beamforming network of the present invention, wherein a is a schematic diagram of a 2-way power divider circuit, and b is a schematic diagram of a Butler matrix circuit and a cross-connection of a phase shifter;

[0031] Figure 6 The circuit structure diagram of the 3×3 Butler matrix of the beamforming network;

[0032] Figure 7 The circuit structure diagram of the 4×4 Butler matrix of the beamforming network;

[0033] Figure 8 is a connection diagram of the second power divider network and the phase compensation circuit of the present invention, wherein a is a connection diagram of the first beam to the fifth beam, and b is a connection diagram of the sixth beam to the ninth beam;

[0034] Fig. 9 The synthetic azimuth plane pattern of nine beams at a frequency of 1710 MHz measured in an embodiment of the present invention;

[0035] Fig.10 This is the synthetic azimuth plane pattern of nine beams at a frequency of 2690 MHz measured in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the present invention clearer, the following describes the implementation of the present invention through specific examples and in combination with the accompanying drawings. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific examples, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0037] The present invention proposes a broadband nine-beam array antenna, which specifically includes a metal reflector, a radiation unit array, a beam forming network, a first power divider network, a second power divider network and a phase compensation circuit;

[0038] The radiation unit array is connected to the second power divider network and fixedly mounted on the metal reflector; the beam forming network is connected to the first power divider network through the phase compensation circuit and fixedly mounted on the metal reflector;

[0039] The radiation unit array includes more than or equal to 2 radiation unit groups, each of the radiation unit groups is arranged in the horizontal direction, and at least one radiation unit group is offset in the horizontal direction;

[0040] The radiation unit group includes greater than or equal to 12 radiation units;

[0041] There are at least two beamforming networks, each of which includes a 12-way Butler matrix circuit and a 2-way power divider group;

[0042] There are at least eight phase compensation circuits, and each of the phase compensation circuits includes two independent transmission lines.

[0043] The number of the radiation unit groups is 6, and the radiation units are dual-polarization antenna units.

[0044] Adjacent rows of the radiation element array are arranged in a horizontally offset manner.

[0045] Specifically, adjacent rows of the radiation element array are arranged in a horizontally offset manner, such as Figure 1As shown. A plurality of radiation elements 101 are arranged in a row to form a radiation element group 111, the horizontal spacing of the radiation elements is HD, the vertical spacing is VD, and the horizontal offset distance of adjacent rows is HD1. Preferably, the number of radiation elements in each row N=20 and the horizontal spacing is equal, the number of rows M=6 and the vertical spacing of adjacent rows is equal; preferably, the second row radiation element group 112, the fourth row radiation element group 114, and the sixth row radiation element group 116 are all offset to the right by HD1 relative to the first row 111; the third row radiation element group 113 and the fifth row radiation element group 115 are not offset relative to the first row 111. Preferably, the radiation element 101 is a ±45 dual-polarized cross dipole antenna, a patch antenna and a slot antenna.

[0046] In an embodiment of the present invention, the first power divider network includes at least 8 2-way power divider circuits, and the input port of the first power divider network is the input port of the antenna; the second power divider network includes at least 24 3-way power divider circuits; the output port of the 3-way power divider circuit is connected to three radiating units located at the same horizontal position in different rows, and the input port of the 3-way power divider circuit is connected to the output port of the beamforming network.

[0047] In an embodiment of the present invention, each of the 12-way Butler matrix circuits includes 4 3×3 Butler matrix circuits, 3 4×4 Butler matrix circuits and 9 phase shifters; the 3×3 Butler matrix circuit and the 4×4 Butler matrix circuit are cross-connected through the phase shifter. Each of the 12-way Butler matrix circuits includes 12 input ports isolated from each other and 12 output ports isolated from each other, wherein 3 input ports are connected to a 50 ohm load and grounded, and the remaining input ports serve as 9 input ports of the beamforming network, namely, the first input port, the second input port, the third input port, the fourth input port, the fifth input port, the sixth input port, the seventh input port, the eighth input port and the ninth input port, and correspond to the first beam, the second beam, the third beam, the fourth beam, the fifth beam, the sixth beam, the seventh beam, the eighth beam and the ninth beam, respectively.

[0048] Preferably, the azimuth angle range of the first beam is 25 to 50 degrees, the azimuth angle range of the second beam is 18 to 35 degrees, the azimuth angle range of the third beam is 10 to 25 degrees, the azimuth angle range of the fourth beam is 5 to 15 degrees, the azimuth angle range of the fifth beam is 0 degree, the azimuth angle range of the sixth beam is -5 to -15 degrees, the azimuth angle range of the seventh beam is -10 to -25 degrees, the azimuth angle range of the eighth beam is -18 to -35 degrees, and the azimuth angle range of the ninth beam is -25 to -50 degrees.

[0049] The phase difference between the two independent transmission lines is in the range of 0 degree to 90 degrees.

[0050] The horizontal spacings of the radiation units in the radiation unit group are equal, and the vertical spacings between the radiation unit groups are equal;

[0051] The spacing is 0.4 to 0.95 times the wavelength of the center frequency of the array antenna operating frequency band;

[0052] The horizontal offset distance of each row of radiation elements is half of the horizontal distance of the radiation elements.

[0053] That is, the radiating elements of each row are connected to the output port of the second power divider network, the second power divider network is composed of a plurality of 3-way power divider circuits, and the number of 3-way power divider circuits is 80. The three radiating elements at the same horizontal position in each column of the array are connected to the same 3-way power divider circuit output port, and one of the polarized connections is as follows Figure 3 As shown. The first column of radiating elements is connected as follows: the +45 polarization of radiating elements d(1,1), d(3,1) and d(5,1) is connected to the output port of the 3-way power divider circuit 201, and the +45 polarization of radiating elements d(2,1), d(4,1) and d(6,1) is connected to the output port of another 3-way power divider circuit 221. The connections of the other columns of radiating elements and the 3-way power divider circuit are similar. Figure 3 The connections for the +45 polarization of the radiating element are shown, the connections for the -45 polarization are similar.

[0054] Preferably, the input port of the 3-way power splitter circuit is connected to the output port of the beamforming network, such as Figure 4 As shown. The input port of the 3-way power splitter circuit connecting the 1st, 3rd and 5th row radiation units is connected to the output port of the beam forming network 302; the input port of the 3-way power splitter circuit connecting the 2nd, 4th and 6th row radiation units is connected to the output port of the beam forming network 301. The beam forming network has 9 input ports, and the number of output ports is equal to the number of columns of the array N=20. Figure 4 The connection diagram for +45 polarization is shown, and the connection for -45 polarization is similar. The dual-polarization wideband nine-beam antenna includes four beam forming networks.

[0055] like Figure 5As shown in a and b, each beamforming network includes a 2-way power divider circuit group 315, a 3×3 Butler matrix circuit group (314-1 to 314-4), a 4×4 Butler matrix circuit group (313-1 to 313-3), and 9 phase shifters 312. One input port of the 4×4 Butler matrix circuit is connected to a 50 resistor and then grounded. The 2-way power divider circuit group includes 8 2-way power dividers, which function to form a conical distribution of the amplitude of the excitation signal of the radiating unit in the horizontal direction of the array to suppress the near side lobes and control the beam crossover level. Each of the 3×3 Butler matrix circuits includes 3 90-degree mixers 312 and 3 phase shifters 311, as shown in FIG. Figure 6 Each of the 4×4 Butler matrix circuits includes four 90-degree mixers 312 and two 45-degree phase shifters 311. Figure 7 As shown. The output port of the 4×4 Butler matrix circuit group is cross-connected with the input port of the 3×3 Butler matrix circuit group through the phase shifter 311, and some output ports of the 3×3 Butler matrix circuit are connected to the input port of the 2-way power divider. The 9 input ports (411 to 419) of the 4×4 Butler matrix circuit group are the input ports of the beamforming network, corresponding to 9 different beam directions respectively; the output port of the 2-way power divider circuit group and the output ports of some 3×3 Butler matrix circuits not connected to the 2-way power divider are the output ports of the beamforming network, connected to the input ports of the 3-way power divider circuit of the second power divider network.

[0056] The first input port, the second input port, the third input port, the fourth input port, the sixth input port, the seventh input port, the eighth input port and the ninth input port of the beamforming network are connected to the first power divider network through the phase compensation circuit.

[0057] Preferably, the input port of the beamforming network is connected to the first power divider network via a phase compensation circuit, such as Figure 8 The first power divider network is composed of 16 2-way power divider circuits. The phase compensation circuit includes two independent transmission lines, the phase difference between the two is The input ports 411 and 421 of the first beam of the two beam forming networks are connected to the two-way power divider circuit 501 through the phase compensation circuit 401, the input ports 412 and 422 of the second beam are connected to the two-way power divider circuit 502 through the phase compensation circuit 402, the input ports 413 and 423 of the third beam are connected to the two-way power divider circuit 503 through the phase compensation circuit 403, and the input ports 414 and 424 of the fourth beam are connected to the two-way power divider circuit 504 through the phase compensation circuit 404. 504; the input ports 416 and 426 of the sixth beam are connected to the two-way power divider circuit 506 through the phase compensation circuit 406; the input ports 417 and 427 of the seventh beam are connected to the two-way power divider circuit 507 through the phase compensation circuit 407; the input ports 418 and 428 of the eighth beam are connected to the two-way power divider circuit 508 through the phase compensation circuit 408; the input ports 419 and 429 of the ninth beam are connected to the two-way power divider circuit 509 through the phase compensation circuit 409. The input ports 415 and 425 of the fifth beam are directly connected to the two-way power divider circuit 508. The connection of -45 polarization is similar.

[0058] Preferably, the horizontal offset distance HD1 of each row of radiation units is half of the horizontal distance of the radiation units, that is, HD1=HD / 2, the phase difference of the phase compensation circuits corresponding to the first and ninth beams is 60 degrees, the phase difference of the phase compensation circuits corresponding to the second and eighth beams is 45 degrees, the phase difference of the phase compensation circuits corresponding to the third and seventh beams is 30 degrees, the phase difference of the phase compensation circuits corresponding to the fourth and sixth beams is 15 degrees, and the fifth beam does not need to be connected to a phase compensation circuit.

[0059] In the embodiment of the present invention, preferably, the number of radiation unit groups M=6, the number of radiation units in each radiation unit group N=20, and the number of beamforming networks is 4. The antenna includes 20 3-way power splitter groups, and each 3-way power splitter group includes 4 3-way power splitters, which has the best effect.

[0060] In the embodiment of the present invention, the antenna operating frequency band is 1427-2700MHz. Preferably, the broadband nine-beam array antenna operating frequency band is 1427-2700MHz, the radiating unit spacing is 80mm, the vertical plane spacing is 110mm, the adjacent row offset distance is 40mm, and the radiating units in each column are set to form a 6-degree downtilt angle with a phase difference. The array antenna forms nine beams in the azimuth plane, and the vertical plane inclination angle of each beam is 6 degrees. Fig. 9 This is the test synthesis pattern of nine beams in the azimuth plane at the 1700MHz frequency point. Fig.10The test synthesis pattern of nine beams in the azimuth plane at the frequency of 2700MHz. It can be seen that the cross level of the nine beams in the azimuth plane is -10dB, and the side lobe and grating lobe level suppression are better than 16dB, with little interference, which can maximize the capacity.

[0061] The nine-beam antenna of the embodiment has a fixed electronic downtilt angle, which is suitable for scenarios with very dense users, such as large sports stadiums, performing arts centers and squares. When using multiple pairs of nine-beam antennas, the communication capacity can be increased several times by fine cell division for application scenarios such as venues. Compared with the traditional conventional base station antenna with a beam width of 65 degrees, not only the capacity is increased by cell splitting, but also the ultra-wideband (relative bandwidth greater than 60%) has lower azimuth sidelobes, the cell has little interference with neighboring cells, and the network rate is high. The traditional nine-sector division requires nine narrow beam antennas, each of which is very large and very difficult to install on an antenna tower at the same time. This embodiment only requires one pair of antennas to achieve nine sectors, which can be conveniently configured on an antenna tower.

[0062] It should be emphasized that in the above embodiments, the spacing between two adjacent radiating units in the horizontal direction of the antenna array is fixed, that is, the radiating units are arranged at equal intervals. However, in actual engineering applications, the vibrator units may also be arranged at unequal intervals. Similarly, the two vibrators in the vertical direction may also be arranged at unequal intervals. In the embodiment, the 2nd, 4th, and 6th rows are offset to the right relative to the 1st, 3rd, and 5th rows. In actual applications, they may also be offset to the left. This staggered arrangement of the vibrators can also achieve a multi-beam radiation pattern with low side lobes in an ultra-wideband range, which is also within the scope of protection of the present invention because it does not deviate from the concept of the present invention.

[0063] In the above-mentioned broadband nine-beam array antenna, each radiating unit group includes N radiating units arranged in the horizontal direction, multiple radiating unit groups are offset in the horizontal direction, and multiple phase compensation circuits are used to perform phase compensation on the radiating unit groups offset in the horizontal direction. In this way, a scheme in which radiating units in different rows are offset in the horizontal direction according to a certain rule is adopted, and a certain phase compensation is added to the offset radiating units in the feeding network. The nine-beam antenna has good sidelobe and grating lobe suppression performance in the ultra-wide frequency band, reduces the interference of neighboring cells corresponding to the beam, realizes frequency reuse of adjacent cells without increasing antenna sites and sky resources, and improves network capacity.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Obviously, the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A broadband nine-beam array antenna, characterized in that: It includes a metal reflector, a radiation unit array, a beam forming network, a first power divider network, a second power divider network and a phase compensation circuit, and the antenna operates in a frequency band of 1427-2700MHz; The radiation unit array is connected to the second power divider network and fixedly mounted on the metal reflector; the beam forming network is connected to the first power divider network through the phase compensation circuit and fixedly mounted on the metal reflector; The radiation element array includes 6 radiation element groups, each radiation element group is arranged in the horizontal direction, and at least one radiation element group is offset in the horizontal direction; The radiation unit group includes greater than or equal to 12 radiation units; There are at least two beamforming networks, each of which includes a 12-way Butler matrix circuit and a 2-way power divider group; There are at least 8 phase compensation circuits, and each phase compensation circuit includes 2 independent transmission lines; The radiation unit is a dual-polarization antenna unit; adjacent rows of the radiation unit array are arranged in a horizontally offset manner; A plurality of radiating elements are arranged in a row to form a radiating element group, the horizontal spacing of the radiating elements is HD, the vertical spacing is VD, and the horizontal offset distance of adjacent rows is HD1; the number of radiating elements in each row is N=20 and the horizontal spacing is equal, the number of rows is M=6 and the vertical spacing of adjacent rows is equal; the 2nd row radiating element group, the 4th row radiating element group, and the 6th row radiating element group are all offset right by HD1 relative to the 1st row; the 3rd row radiating element group and the 5th row radiating element group are not offset relative to the 1st row, and the radiating elements are ±45 dual-polarized cross dipole antennas, patch antennas or slot antennas; The first power divider network includes at least 8 2-way power divider circuits, and the input port of the first power divider network is the input port of the antenna; the second power divider network includes at least 24 3-way power divider circuits; the output port of the 3-way power divider circuit is connected to three radiating elements in different rows and located at the same horizontal position, and the input port of the 3-way power divider circuit is connected to the output port of the beam forming network; The input port of the 3-way power splitter circuit connected to the radiating elements in the 1st, 3rd and 5th rows is connected to the output port of the first beam forming network; The input ports of the 3-way power splitter circuits connected to the 2nd, 4th and 6th row radiation elements are connected to the output ports of the second beamforming network; the beamforming network has 9 input ports, and the number of output ports is equal to the number of columns of the array N=20; The spacing between two adjacent radiating elements in the horizontal direction of the antenna array is fixed, the radiating elements are arranged at equal spacing, or the radiating elements are arranged at unequal spacing; the two radiating elements in the vertical direction are arranged at unequal spacing; a multi-beam radiation pattern with low side lobes in an ultra-wideband range; Each of the 12-way Butler matrix circuits includes 4 3×3 Butler matrix circuits, 3 4×4 Butler matrix circuits and 9 phase shifters; the 3×3 Butler matrix circuit and the 4×4 Butler matrix circuit are cross-connected through the phase shifter, and each of the 12-way Butler matrix circuits includes 12 input ports isolated from each other and 12 output ports isolated from each other, wherein 3 input ports are connected to a 50-ohm load and grounded, and the remaining input ports serve as 9 input ports of the beamforming network, namely, a first input port, a second input port, a third input port, a fourth input port, a fifth input port, a sixth input port, a seventh input port, an eighth input port and a ninth input port, and correspond to a first beam, a second beam, a third beam, a fourth beam, a fifth beam, a sixth beam, a seventh beam, an eighth beam and a ninth beam, respectively; The 9 input ports of the 4×4 Butler matrix circuit are input ports of the beamforming network, corresponding to 9 different beam directions respectively; the output port of the 2-way power splitter circuit and the output ports of some 3×3 Butler matrix circuits not connected to the 2-way power splitter are output ports of the beamforming network, connected to the input ports of the 3-way power splitter circuit of the second power splitter network; The phase difference of the phase compensation circuits corresponding to the first and ninth beams is 60 degrees, the phase difference of the phase compensation circuits corresponding to the second and eighth beams is 45 degrees, the phase difference of the phase compensation circuits corresponding to the third and seventh beams is 30 degrees, the phase difference of the phase compensation circuits corresponding to the fourth and sixth beams is 15 degrees, and the fifth beam does not need to be connected to a phase compensation circuit.

2. The broadband nine-beam array antenna according to claim 1, characterized in that: The azimuth angle range of the first beam is 25 to 50 degrees, the azimuth angle range of the second beam is 18 to 35 degrees, the azimuth angle range of the third beam is 10 to 25 degrees, the azimuth angle range of the fourth beam is 5 to 15 degrees, the azimuth angle range of the fifth beam is 0 degree, the azimuth angle range of the sixth beam is -5 to -15 degrees, the azimuth angle range of the seventh beam is -10 to -25 degrees, the azimuth angle range of the eighth beam is -18 to -35 degrees, and the azimuth angle range of the ninth beam is -25 to -50 degrees.

3. The broadband nine-beam array antenna according to claim 1, characterized in that: The phase difference between the two independent transmission lines is in the range of 0 degree to 90 degrees.

4. The broadband nine-beam array antenna according to claim 1, characterized in that: The spacing is 0.4 to 0.95 times the wavelength of the center frequency of the array antenna operating frequency band; The horizontal offset distance of each row of radiation elements is half of the horizontal distance of the radiation elements.

5. The broadband nine-beam array antenna according to claim 1, characterized in that: The first input port, the second input port, the third input port, the fourth input port, the sixth input port, the seventh input port, the eighth input port and the ninth input port of the beamforming network are connected to the first power divider network through the phase compensation circuit.

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