A large-scale array shaped beam nulling method

Abstract

The present application relates to a kind of large-scale array shaped beam main lobe nulling method, comprising: assuming that antenna array has M rows N columns, according to the beam width of phased array single point beam and the coverage range of the shaped beam pattern to be formed, determine the number of point beam, point beam weight and specific beam position needed, so that the set of point beam can cover the coverage range of shaped beam pattern;Determine the position of the null needed in the shaped beam pattern, correct different point beam weights according to the null position;According to the point beam weight after correction, the unit excitation coefficient of the mth row n column is calculated using superposition principle;According to the calculated unit excitation coefficient, the actual shaped beam pattern containing null that can be generated is obtained.The present application method can form a specific shape beam and form null in a specific position, the required computing resource is minimal, and real-time calculation on the star can be realized.

Description

Technical Field

[0001] This invention belongs to the field of spaceborne communication antenna technology and relates to a method for nulling the main lobe of a large-scale array shaped beam. Background Technology

[0002] Satellite communication boasts numerous advantages, including large coverage area, long communication distance, large system capacity, convenient and rapid network setup, and seamless global connectivity, making it a crucial means of global communication. Its superior characteristics also make it an important communication tool in the military field, applicable to reconnaissance and early warning, military command and control, and other areas, serving as an indispensable information transmission method in modern information warfare. The communication links, a key component of satellite communication systems, inevitably become a target for enemy interference and disruption, making research on anti-jamming measures for communication satellites a hot topic in the development of satellite communication.

[0003] The superior beam agility of large-scale phased array antennas has led to their widespread application in satellite communications. Satellite communication systems require antenna patterns with strong directivity and low sidelobes. Sometimes, to cover specific countries and regions while maintaining stable signal levels within the area, shaped patterns with specific configurations are required. Satellite communications are often affected by ground-based or low-altitude interference sources. For interference at the same frequency, the receiving antenna pattern needs to form a null in the direction of the incoming interference wave to prevent interference from affecting the communication process.

[0004] The existing literature on beamforming synthesis methods mainly falls into two categories. One category is the staggered projection method, represented by Fourier transform. This is an iterative synthesis method with fast convergence speed, but it requires a high-quality initial radiation pattern function to ensure convergence. The other category is the stochastic optimization method, represented by genetic algorithms. The time required for this type of method to obtain the result depends on the amount of computing resources available, and therefore often requires massive computing resources and a long computation time when synthesizing ultra-large arrays. Summary of the Invention

[0005] The technical problem solved by this invention is to overcome the shortcomings of existing technologies and provide a method for nulling the main lobe of a large-scale array-shaped beam, used to form a beam of a specific shape and create nulls at specific locations. This method requires minimal computational resources and can be implemented in real time on satellite.

[0006] The technical solution of this invention is: utilizing the beam scanning characteristics of a phased array, point beams scanned in different directions are superimposed and stitched into the required shape, while the weight of each point beam is controlled to adjust the level, so that the beam shape can be approximately shaped as required.

[0007] Specifically, in the first aspect, a method for nulling the main lobe of a large-scale array-shaped beam is proposed, comprising the following steps:

[0008] S1. Assume the antenna array consists of M rows and N columns, with the spacing between the elements in each row and column being d. x ,d y Based on the beamwidth of a single point beam in the phased array and the coverage area of ​​the shaped beam pattern to be formed, the required number of point beams, the point beam weights, and the specific beam positions are determined so that the set of point beams can cover the coverage area of ​​the shaped beam pattern.

[0009] S2. Determine the position of the desired null in the shaped beam pattern, and adjust the point beam weights according to the null position;

[0010] S3. Based on the corrected spot beam weights, use the superposition principle to calculate the element excitation coefficients in the m-th row and n-th column, where m = 1, 2, ..., M, n = 1, 2, ..., N;

[0011] S4. Based on the excitation coefficients of each unit calculated in step S3, obtain the actual shaped beam pattern containing nulls that can be generated.

[0012] Furthermore, step S1, which involves determining the required number of spot beams, spot beam weights, and specific beam positions, specifically includes:

[0013]

[0014]

[0015]

[0016] in, To shape the beam pattern, The beam pointing position is The spot beam, where K is the number of spot beams, k = 2π / λ, b i The weight of the i-th point beam is determined according to the height of the shaped beam at that point. Let a be the direction of the i-th point beam in spherical coordinates; mn This represents the initial unit excitation amplitude.

[0017] Furthermore, step S2, which involves correcting the beam weights for different point beams based on the null position, specifically involves:

[0018] Based on the desired null position in the UV space (U0, V0), and the i-th point beam in the UV space (U... i V i ), calculate the corrected spot beam weights b i ′:

[0019]

[0020] Furthermore, step S3, which involves calculating the cell excitation coefficient in the m-th row and n-th column, specifically involves:

[0021]

[0022] Among them, I mn is the unit excitation coefficient in the m-th row and n-th column.

[0023] Furthermore, the shaped beam pattern containing nulls that can actually be generated in step S4 is specifically as follows:

[0024]

[0025] in, This is the actual shaped beam pattern.

[0026] Furthermore, the method also includes:

[0027] Actual shaped beam pattern The actual null position is oriented in UV space (U real V real The difference between the expected null position and the direction (U0, V0) in the UV space is obtained by comparing the two, and the difference is defined as Δu:

[0028]

[0029] With the goal of minimizing Δu, the corrected spot beam weights b are... i Make fine adjustments and repeat steps S3 to S4 to generate a new actual shaped beam pattern. Then, Δu is recalculated, and repeated iterations are performed to obtain an actual shaped beam pattern with a smaller Δu. And even deeper zero-depression depths.

[0030] Furthermore, iterative methods include gradient descent, with no more than 5 iterations.

[0031] Secondly, a computer-readable storage medium is proposed, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the steps of the large-scale array shaped beam main lobe nulling method.

[0032] Thirdly, an electronic device is proposed, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the large-scale array shaped beam main lobe nulling method.

[0033] The advantages of this invention compared to the prior art are:

[0034] (1) The beamforming algorithm of the present invention can realize beamforming and zeroing of large-scale and ultra-large-scale arrays.

[0035] (2) The present invention can form beams of arbitrary shape and form nulls at any position of the main lobe of the beam.

[0036] (3) The beamforming algorithm of the present invention has a very small computational load and can be performed in an embedded system. Attached Figure Description

[0037] Figure 1 A flowchart of a method for nulling the main lobe of a large-scale array shaped beam;

[0038] Figure 2 This is a schematic diagram illustrating the application of 317 point beams to form a circular wide beam in an embodiment of the present invention;

[0039] Figure 3 The 24×24 array excitation amplitude obtained in the embodiment of the present invention;

[0040] Figure 4 The 24×24 array excitation phase obtained in the embodiment of the present invention;

[0041] Figure 5 This is a radiation pattern containing zero traps obtained in an embodiment of the present invention. Detailed Implementation

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0043] like Figure 1 As shown, the present invention proposes a method for nulling the main lobe of a large-scale array shaped beam, comprising the following steps:

[0044] S1. Assume the antenna array consists of M rows and N columns, with the spacing between the elements in each row and column being d. x ,d y Based on the beamwidth of a single point beam in the phased array and the coverage area of ​​the required shaped beam pattern, the required number of point beams, beam weights, and specific beam positions are determined so that the set of point beams can cover the coverage area of ​​the shaped beam pattern.

[0045]

[0046]

[0047]

[0048] in, To shape the beam pattern, The beam pointing position is The spot beam, where K is the number of spot beams, k = 2π / λ, b i The weight of the i-th point beam is determined according to the height of the shaped beam at that point. Let a be the direction of the i-th point beam in spherical coordinates; mn As the initial unit excitation amplitude, in this embodiment, all a can be considered as... mn All are 1.

[0049] S2. Determine the position of the desired null in the shaped beam pattern, and adjust the point beam weights according to the null position. The specific correction formula is as follows:

[0050] Based on the desired null position in the UV space (U0, V0), and the i-th point beam in the UV space (U... i V i ), calculate the corrected spot beam weights b i ′:

[0051]

[0052] S3. Based on the corrected point beam weights, use the superposition principle to calculate the element excitation coefficients in the m-th row and n-th column, where m = 1, 2, ..., M and n = 1, 2, ..., N.

[0053] The unit excitation coefficient I in the m-th row and n-th column mn The calculation method is as follows:

[0054]

[0055] S4. Based on the excitation coefficients of each element calculated in step S3, obtain the actual shaped beam pattern containing nulls that can be generated:

[0056]

[0057] in, This is the actual shaped beam pattern.

[0058] S5. Transform the actual beam pattern The actual null position is oriented in UV space (U real V real The difference between the expected null position and the direction (U0, V0) in the UV space is obtained by comparing the two, and the difference is defined as Δu:

[0059]

[0060] With the goal of minimizing Δu, the corrected spot beam weights b are... i Make fine adjustments and repeat steps S3 to S4 to generate a new actual shaped beam pattern. Then, Δu is recalculated, and repeated iterations are performed to obtain an actual shaped beam pattern with a smaller Δu. And even deeper zero-depression depths.

[0061] Among them, the corrected spot beam weights b i When making fine adjustments, it can be done by adjusting b. i The null position (U0,V0) in the calculation formula is corrected, that is, (U0,V0) is adjusted to a new (U0′,V0′), and b is recalculated. i Achieve a fine-tuning.

[0062] In step S5, the iterative method includes, but is not limited to, local convex optimization methods such as gradient descent. The number of iterations typically does not exceed 3-5.

[0063] Step S5 is not mandatory. Steps S1 to S4 can already generate nulls. Step S5 is only used when the system has extremely high requirements for null depth in order to ensure the signal-to-noise ratio. During the iteration process of step S5, only the null position is used as a fine-tuning variable for iteration, and it is not necessary to use the excitation coefficients of all elements in the array as variables, which greatly simplifies the computational complexity.

[0064] The method proposed in this invention is applicable to planar or non-planar arrays, as well as sparse or dense arrays.

[0065] Example 1

[0066] This verification example uses a uniformly arranged planar antenna array, 24 rows × 24 columns. It forms a wide beam of ±2.5° and produces a null at (1°, 0°).

[0067] The circular wide beam profile composed of 317 point beams is determined using the method in step S1, as follows: Figure 2 As shown. The initial weights b for all beams. i All are 1.

[0068] Using the formula described in step S2, for b1~b 317 After correction, we obtain b1′~b 317 ′.

[0069] The unit excitation coefficient is calculated using the formula described in step S3, as follows: Figure 3 , Figure 4 As shown.

[0070] Finally, in step S4, the generated radiation pattern containing null traps is as follows: Figure 5 As shown.

[0071] This application provides a computer-readable storage medium storing computer instructions that, when executed on a computer, cause the computer to perform... Figure 1 The method described.

[0072] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0073] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0074] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0075] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0076] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

[0077] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for nulling the main lobe of a large-scale array shaped beam, characterized in that, Includes the following steps: S1. Assume the antenna array consists of M rows and N columns, with the spacing between the elements in each row and column being respectively... Based on the beamwidth of a single point beam in the phased array and the coverage area of ​​the shaped beam pattern to be formed, the required number of point beams, the point beam weights, and the specific beam positions are determined so that the set of point beams can cover the coverage area of ​​the shaped beam pattern. S2. Determine the position of the desired null in the shaped beam pattern, and adjust the point beam weights according to the null position; S3. Based on the corrected point beam weights, use the superposition principle to calculate the element excitation coefficients in the m-th row and n-th column, where m = 1, 2, ..., M, n = 1, 2, ..., N; S4. Based on the excitation coefficients of each unit calculated in step S3, obtain the actual shaped beam pattern containing nulls that can be generated. Step S2, which involves correcting the beam weights for different spot beams based on the null position, specifically includes: Based on the direction representation of the expected null position in UV space ( ), and the i The pointing representation of a point beam in the UV space ( ), calculate the corrected spot beam weights : in, For the first i The weight of each point beam is determined according to the height of the shaped beam at that point.

2. The method for nulling the main lobe of a large-scale array shaped beam according to claim 1, characterized in that, Step S1, which involves determining the required number of spot beams, spot beam weights, and specific beam positions, specifically includes: in, To shape the beam pattern, The beam pointing position is ( () spot beam, K For the number of spot beams, , For the first i The weight of each point beam is determined according to the height of the shaped beam at that point; For the first i The direction of the point beam in the spherical coordinate system; This represents the initial unit excitation amplitude.

3. The method for nulling the main lobe of a large-scale array shaped beam according to claim 2, characterized in that, Step S3, which involves calculating the cell excitation coefficient in the m-th row and n-th column, specifically involves: in, is the unit excitation coefficient in the m-th row and n-th column.

4. The method for nulling the main lobe of a large-scale array shaped beam according to claim 3, characterized in that, The actual shaped beam pattern containing nulls that can be generated in step S4 is specifically as follows: in, This is the actual shaped beam pattern.

5. A method for nulling the main lobe of a large-scale array shaped beam according to claim 4, characterized in that, The method further includes: Actual shaped beam pattern The actual null position in UV space is oriented as follows ( ) and the direction of the expected null position in UV space ( By comparing the two, the differences between them are obtained, and the differences are defined as follows: : ； by Minimize the modified spot beam weights. Make fine adjustments and repeat steps S3 to S4 to generate a new actual shaped beam pattern. And recalculate Repeatedly iterate and try to obtain Smaller actual shaped beam pattern And even deeper zero-depression depths.

6. The method for nulling the main lobe of a large-scale array shaped beam according to claim 5, characterized in that, Iterative methods include gradient descent, with no more than 5 iterations.

7. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 6.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1 to 6.

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