A sparse antenna array for low-orbit satellite internet broadband terminals

Abstract

The present application discloses a sparse antenna array for use in a low-orbit satellite internet broadband terminal, comprising a sparse array: the sparse array comprises a plurality of array units, the array units comprise a plurality of sub-array groups; the sub-array group types include 1-drive-2 sub-arrays and 1-drive-1 sub-arrays; the array units specifically comprise a first sub-array group, a second sub-array group, and a third sub-array group: the first sub-array group and the second sub-array group each comprise two sub-arrays, and the third sub-array group comprises one sub-array. The present application is primarily aimed at low-orbit static communication. By adopting a 1-drive-2 format for the sparse array, two antennas share one channel, reducing the number of channels without increasing the array size, thereby reducing the cost, while not changing the boundary conditions of the antenna array elements and increasing the difficulty of testing and calibration.

Description

Technical Field

[0001] The present application relates to the field of satellite communication antennas, and in particular to a sparse antenna array used in low-orbit satellite Internet broadband terminals. Background Art

[0002] A sparse array antenna is one in which antenna elements are staggered and sparsely distributed across the same antenna aperture. By sharing a single antenna aperture, multiple tactical functions previously performed by separate antennas can be simultaneously performed. Existing broadband terminals for low-orbit satellite communications typically use phased array antennas, typically arranged in a rectangular or triangular grid. Each antenna connects to one T / R channel. Given a given aperture size, the number of antennas in a rectangular or triangular grid is fixed, and the number of channels is the same as the number of antennas. Similarly, for a sparse array, each antenna connects to one T / R channel.

[0003] Through algorithm optimization, the number of antennas in the array can be reduced under the same equivalent aperture, thereby reducing the number of channels. However, to compensate for the aperture efficiency loss caused by sparse arrays, the actual aperture size of the antenna is larger than the equivalent aperture size. From the existing technical solutions, it can be seen that under traditional rectangular grid and triangular grid arrays, the number of antennas and the number of channels correspond one to one, and the number of channels cannot be reduced. For phased arrays, the cost is mainly concentrated in the TR components. It is difficult to reduce the layer cost of low-orbit satellite communication and static communication phased arrays using this method. Sparse arrays increase the array size, and algorithm optimization design is difficult. The boundary conditions of each antenna are different, which increases the difficulty of testing and calibration. Summary of the Invention

[0004] The technical problem to be solved by this application is that the number of channels cannot be reduced, or reducing the number of channels will lead to an increase in array size, difficulty in design, and complex calibration. The purpose is to provide a sparse antenna array for use in low-orbit satellite Internet broadband terminals. By adopting a 1-drive-2 format for the antenna array, two antennas share one channel. The number of channels is reduced without increasing the array size, thereby reducing the cost. At the same time, the boundary conditions of the antenna array elements are not changed, and the difficulty of testing and calibration is not increased.

[0005] This application is implemented through the following technical solutions:

[0006] A sparse antenna array for a low-orbit satellite internet broadband terminal, comprising:

[0007] The sparse array includes a plurality of array units, and the array unit includes a plurality of sub-array groups;

[0008] The sub-array group types include 1 drive 2 sub-arrays and 1 drive 1 sub-array;

[0009] The array unit specifically includes a first sub-array group, a second sub-array group and a third sub-array group: the first sub-array group and the second sub-array group each include two sub-arrays, and the third sub-array group includes one sub-array.

[0010] This application is mainly aimed at low-orbit static communication. By setting a sparse array including several array units, the array unit includes several sub-array groups; the sub-array group types include 1 drive 2 sub-arrays and 1 drive 1 sub-array; by adopting a 1 drive 2 form for the sparse array, two antennas share one channel, and the number of channels is reduced without increasing the array size, thereby reducing the layer cost, while not changing the boundary conditions of the antenna array elements, and will not increase the difficulty of test and calibration.

[0011] Furthermore, the array unit specifically includes a first sub-array group, a second sub-array group and a third sub-array group: the first sub-array group and the second sub-array group each include two sub-arrays, and the third sub-array group includes one sub-array.

[0012] Furthermore, the first sub-array group and the second sub-array group are both 1-drive 2 sub-arrays, the third sub-array group is 1-drive 1 sub-array, and each of the array units includes three first sub-array groups, two second sub-array groups, and two third sub-array groups.

[0013] Furthermore, the array units are arranged in a manner that the number of rows in the y direction is 3 and the number of columns in the x direction is 4, forming a 3*4 arrangement.

[0014] Furthermore, each row of the array unit includes a first sub-array group, and the first sub-array group of each row is offset from the first column backward in the y direction by one unit pitch, where one unit pitch is the position occupied by one sub-array.

[0015] Furthermore, each array unit is provided with a second sub-array group in the first column and the fourth column in the x direction.

[0016] Furthermore, each array unit is provided with a third sub-array group in the first and third rows in the x direction:

[0017] The third sub-array group of the first row is set in the third column;

[0018] The third sub-array group of the third row is arranged in the second column.

[0019] Furthermore, it also includes multi-layer printed circuit boards and motors:

[0020] The sparse array is etched and pressed onto a multilayer printed circuit board;

[0021] The multilayer printed circuit board is connected to the motor.

[0022] Furthermore, the two sub-arrays of the first sub-array group and the two sub-arrays of the second sub-array group are connected via a 1-to-2 power splitter / combiner;

[0023] The common ends of the two sub-arrays of the first sub-array group and the two sub-arrays of the second sub-array group are connected to the T / R components;

[0024] The sub-arrays of the third sub-array group are connected to the T / R components via transmission lines.

[0025] Furthermore, the antenna array is printed on a multilayer printed circuit board. A radome is provided on the other side of the multilayer printed circuit board where the antenna array is connected. The motor is connected to the antenna assembly structure, and the antenna assembly structure controls the motor's mechanical rotation to change the direction of the antenna beam. Using electromechanical scanning, the motor deflects the antenna, similar to the way a fan moves its head, to increase the scanning angle. This effectively reduces the antenna aperture and achieves bottom-level design. During the scanning process, as the antenna's beam scanning angle increases, the antenna gain decreases and the beam widens. When determining the array size, it is necessary to ensure that the antenna gain at the maximum angle meets communication requirements. Motor scanning reduces the antenna's electronic scanning angle. The lower the gain, the smaller the array size required, and the corresponding antenna aperture is smaller. Furthermore, by sparsely expanding the antenna array into a full array with a periodicity, modularization is achieved. Using the array unit with the smallest period as a module and repeatedly expanding it, the design difficulty can be reduced, achieving modularization of product design.

[0026] Compared with the prior art, this application has the following advantages and beneficial effects:

[0027] 1. This application adopts a 1-drive-2 antenna array structure, where two antennas share one channel. This reduces the number of channels without increasing the array size, thereby reducing the cost. At the same time, it does not change the boundary conditions of the antenna elements, and does not increase the difficulty of testing and calibration.

[0028] 2. This application adopts the electromechanical scanning method, which can effectively reduce the antenna aperture and achieve the bottom layer;

[0029] 3. This application adopts array units with 1 drive 2 sub-arrays in the x-direction, 1 drive 2 sub-arrays in the y-direction, and 1 drive 1 sub-array to form array units, and expands multiple array units into a whole array, which can achieve 58% channel sparsity. At the same time, it can realize antenna azimuth angle phi = 0 ~ 360° and vertical axis angle theta = 0 ~ 40° scanning, combine phased array electronic scanning and mechanical scanning to realize electromechanical hybrid scanning, and realize scanning of the whole machine azimuth angle phi = 0 ~ 360° and vertical axis angle theta = 0 ~ 70°, which has the advantages of scanning performance over the traditional 1 drive 2 array method. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present application, the following briefly introduces the drawings required for use in the examples. It should be understood that the following drawings only illustrate certain embodiments of the present application and should not be considered as limiting the scope. A person of ordinary skill in the art can also derive other relevant drawings based on these drawings without inventive effort. In the drawings:

[0031] Figure 1 This is a schematic diagram of an antenna array arrangement in a sparse antenna array channel mode applied to a low-orbit satellite internet broadband terminal according to the present invention;

[0032] Figure 2 This is a schematic diagram of an antenna 1-drive-2 format in a sparse antenna array channel mode applied to a low-orbit satellite internet broadband terminal according to the present invention;

[0033] Figure 3 The present invention is a schematic diagram of a motor and antenna connection method in a sparse antenna array channel mode applied to a low-orbit satellite Internet broadband terminal.

[0034] Markings and corresponding parts names in the accompanying drawings:

[0035] 1. Antenna array; 10. Array unit; 11. First sub-array group; 12. Second sub-array group; 13. Third sub-array group; 14. T / R assembly; 15. 1-to-2 power splitter / combiner; 2. Multilayer printed circuit board; 3. Motor; 4. Radome. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of this application more clear, the present application is further described in detail below in conjunction with examples and drawings. The schematic implementation methods of this application and their descriptions are only used to explain this application and are not intended to limit this application.

[0037] It should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "several" means two or more, unless otherwise specifically defined.

[0038] In the prior art, broadband terminals used for low-orbit satellite communications generally use phased array antennas. The antenna array generally adopts a rectangular grid array or a triangular grid array, and one antenna is connected to one T / R channel.

[0039] The rectangular grid array spacing must meet the following requirements:

[0040]

[0041]

[0042] in, 、 is the scanning angle, is the number of array elements on the azimuth plane, is the number of array elements on the pitch plane.

[0043] The spacing of the triangular grid array must meet the following requirements:

[0044]

[0045] in, , 、 is the scanning angle, is the number of array elements on the azimuth plane, is the number of array elements on the pitch plane.

[0046] It can be seen from this that under a certain aperture size, the number of antennas in the rectangular grid and the triangular grid is a fixed value, and the number of channels is the same as the number of antennas.

[0047] Example 1

[0048] like Figure 1 As shown, this embodiment provides a sparse antenna array for a low-orbit satellite internet broadband terminal, including a sparse array 1:

[0049] The sparse array 1 includes a plurality of array units 10, and the array unit 10 includes a plurality of sub-array groups;

[0050] Subarray group types include 1 drive 2 subarrays and 1 drive 1 subarray;

[0051] The array unit specifically includes a first sub-array group 11, a second sub-array group 12 and a third sub-array group 13: the first sub-array group 11 and the second sub-array group 12 each include two sub-arrays, and the third sub-array group 13 includes one sub-array.

[0052] This application utilizes a sparse array 1 comprising several array elements 10, each of which comprises several sub-array groups; these sub-array groups include 1-drive-2 sub-arrays and 1-drive-1 sub-array. Targeting low-orbit geostationary communication, this application employs a 1-drive-2 configuration for the sparse array 1, with two antennas sharing a single channel. This reduces the number of channels without increasing the array size, thereby lowering the cost. This also maintains the boundary conditions of the antenna elements, thus minimizing the difficulty of testing and calibration.

[0053] like Figure 2As shown, a T / R channel connects two antenna elements and feeds them. In the prior art, the antenna subarray type is usually 1-drive-1, that is, one antenna element is connected to one T / R channel. Because in traditional cases, the array scale is the same as the number of channels, that is, the number of antenna elements is the same as the number of channels. For example, in an m×n planar array, the number of channels in the planar array is m×n.

[0054] The antenna subarray in this application adopts a 1-drive-2 approach, with two antennas sharing one channel. Through reasonable antenna arrangement, the influence of grating lobes can be reduced. Since the grating lobes occupy the radiation energy, the antenna gain is reduced. The target seen from the grating lobes is easily confused with the target seen from the main lobe, resulting in blurred target position. Interference signals entering the receiver from the grating lobes will affect the normal operation of the communication system. Therefore, the array element spacing of the antenna should be reasonably selected to avoid the occurrence of grating lobes. In the extreme case, for an m×n planar array, the number of channels is (m×n) / 2. Therefore, relatively speaking, the number of channels is reduced without reducing the number of antennas.

[0055] In some possible embodiments, the array unit 10 specifically includes a first sub-array group 11 , a second sub-array group 12 , and a third sub-array group 13 : the first sub-array group 11 and the second sub-array group each include two sub-arrays, and the third sub-array group 13 includes one sub-array.

[0056] In some possible embodiments, the first sub-array group 11 and the second sub-array group 12 are both 1-drive-2 sub-arrays, and the third sub-array group 13 is 1-drive-1 sub-array. Each array unit 10 includes three first sub-array groups 11, two second sub-array groups 12, and two third sub-array groups 13.

[0057] In some possible embodiments, the array units 10 are arranged in a manner that the number of rows in the y direction is 3 and the number of columns in the x direction is 4, forming a 3*4 arrangement.

[0058] In some possible embodiments, each row of the array unit 10 includes a first sub-array group 11 . The first sub-array group 11 in each row is offset backward in the y direction by one unit pitch starting from the first column. One unit pitch is the position occupied by one sub-array.

[0059] In some possible embodiments, each array unit 10 is provided with a second sub-array group 12 in the first column and the fourth column in the x-direction.

[0060] In some possible embodiments, each array unit 10 is provided with a third sub-array group 13 in the first and third rows in the x-direction:

[0061] The third sub-array group 13 of the first row is arranged in the third column;

[0062] The third sub-array group 13 of the third row is arranged in the second column.

[0063] In some possible embodiments, the two sub-arrays of the first sub-array group 11 and the two sub-arrays of the second sub-array group 12 are connected via a 1-to-2 power splitter / combiner 15;

[0064] The common ends of the two sub-arrays of the first sub-array group 11 and the two sub-arrays of the second sub-array group 12 are connected to the T / R assembly 14;

[0065] The sub-arrays of the third sub-array group 13 are connected to the T / R assembly 14 via transmission lines.

[0066] In some possible embodiments, the common end of the first sub-array group 11 in the first row in the y direction of the array unit 10 faces the second row and is connected to the T / R assembly 14; the common end of the first sub-array group 11 in the second row in the y direction faces the first column and is connected to the T / R assembly 14; and the common end of the first sub-array group 11 in the third row in the y direction faces the second row and is connected to the T / R assembly 14.

[0067] The common end of the second sub-array group 12 in the first column in the x-direction of the array unit 10 faces the second column and is connected to the T / R assembly 14 , and the common end of the second sub-array group 12 in the fourth column in the x-direction faces the third column and is connected to the T / R assembly 14 ;

[0068] The third sub-array group 13 of the first row in the y direction of the array unit 10 is connected to the T / R element 14 toward the second column. The third sub-array group 13 of the first row in the y direction is connected to the T / R element 14 toward the second column.

[0069] like Figure 3 As shown, it also includes a multilayer printed circuit board 2 and a motor 3: the sparse array 1 is etched and pressed on the multilayer printed circuit board 2; the multilayer printed circuit board 2 is connected to the motor 3, and an antenna cover 4 is provided on the other side of the sparse array 1 connected to the multilayer printed circuit board 2.

[0070] In some possible embodiments, the motor 3 is connected to the antenna structure, and the antenna structure controls the mechanical rotation of the motor 3 to change the direction of the antenna beam. The use of electromechanical scanning can effectively reduce the antenna aperture and achieve low cost.

[0071] The key point of this technology is that the array unit 10 is formed by using a 1-drive-2 sub-array in the x-direction, a 1-drive-2 sub-array in the y-direction, and a 1-drive-1 sub-array, and multiple array units 10 are expanded into a full array. This can achieve 58 percent channel sparsity, effectively reducing channel costs.

[0072] The system can simultaneously scan the antenna in azimuth angles of phi = 0 to 360° and in vertical axis angles of theta = 0 to 40°. Combining phased array electronic scanning with mechanical scanning enables electromechanical hybrid scanning, enabling scanning of the entire system in azimuth angles of phi = 0 to 360° and in vertical axis angles of theta = 0 to 70°. This system offers advantages over the traditional 1-drive-2 array scanning method. Periodic units consist of a 1-drive-2 subarray in the x-direction, a 1-drive-2 subarray in the y-direction, and a 1-drive-1 subarray.

[0073] The periodic unit is composed of one drive 2 sub-arrays in the x direction, one drive 2 sub-arrays in the y direction, and one drive 1 sub-array. The specific arrangement is Figure 1 In this arrangement, the theoretically calculated antenna pattern can achieve scanning in the azimuth angle phi = 0-360° and the vertical axis angle theta = 0-40°; then, based on this, motor 3 is used to deflect the antenna, similar to the way a fan shakes its head to increase the scanning angle.

[0074] During scanning, as the antenna's beam scanning angle increases, the antenna's gain decreases and the beam widens. When determining the array size, it's important to ensure that the antenna's gain at the maximum angle meets communication requirements. Scanning with motor 3 reduces the antenna's electronic scanning angle, resulting in a lower gain and a smaller array size, which in turn requires a smaller antenna aperture. Furthermore, by expanding the sparse array 1 into a full array with periodic sparse expansion, modularization is achieved. Using the array unit 10 with the minimum period as a module, repeated expansion reduces design complexity and enables modular product design.

[0075] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of this application. It should be understood that the above description is only the specific implementation methods of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. A sparse antenna array for a low-orbit satellite internet broadband terminal, characterized in that: Including sparse arrays (1): The sparse array (1) includes a plurality of array units (10), and the array unit (10) includes a plurality of sub-array groups; The sub-array group types include 1 drive 2 sub-arrays and 1 drive 1 sub-array; The array unit (10) specifically includes a first sub-array group (11), a second sub-array group (12), and a third sub-array group (13): the first sub-array group (11) and the second sub-array group each include two sub-arrays, and the third sub-array group (13) includes one sub-array; The first sub-array group (11) and the second sub-array group (12) are both 1-drive 2-sub-arrays; The third sub-array group (13) is a 1-drive-1 sub-array; Each of the array units (10) includes three first sub-array groups (11), two second sub-array groups (12) and two third sub-array groups (13); The array units (10) are arranged in such a manner that the number of rows in the y direction is 3 and the number of columns in the x direction is 4, forming a 3×4 periodic arrangement; Each row of the array unit (10) includes a first sub-array group (11), and the first sub-array group (11) of each row is offset backward in the y direction by one unit spacing starting from the first column, wherein one unit spacing is the position occupied by one sub-array; Each array unit (10) is provided with a second sub-array group (12) in the first column and the fourth column in the x-direction; Each array unit (10) is provided with a third sub-array group (13) in the first and third rows in the x-direction: The third sub-array group (13) of the first row is set in the third column; The third sub-array group (13) of the third row is arranged in the second column.

2. The sparse antenna array for low-orbit satellite internet broadband terminal according to claim 1, characterized in that: The two sub-arrays of the first sub-array group (11) and the two sub-arrays of the second sub-array group (12) are connected via a 1-to-2 power splitter / combiner (15); The common ends of the two sub-arrays of the first sub-array group (11) and the two sub-arrays of the second sub-array group (12) are connected to the T / R component (14); The sub-arrays of the third sub-array group (13) are connected to the T / R components (14) via transmission lines.

3. The sparse antenna array for low-orbit satellite internet broadband terminal according to claim 1, characterized in that: Also included are a multilayer printed circuit board (2) and a motor (3): The sparse array (1) is etched and pressed onto a multilayer printed circuit board (2); The multilayer printed circuit board (2) is connected to the motor (3).

4. The sparse antenna array for low-orbit satellite internet broadband terminal according to claim 3, characterized in that: The other side of the sparse array (1) connected to the multilayer printed circuit board (2) is provided with a radome (4).

5. The sparse antenna array for low-orbit satellite internet broadband terminal according to claim 4, characterized in that: The motor (3) is connected to the antenna complete structure, and the antenna complete structure controls the mechanical rotation of the motor (3) to change the direction of the antenna beam.

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