Method for obtaining and separating the scattering field of a large array antenna

Abstract

The application discloses a method for obtaining and separating a scattering field of a large-scale array antenna, and the steps are as follows: obtaining a radiation field of each unit array of a subarray, and calculating a scattering field of an antenna mode item in each unit array; using the scattering field of the antenna mode item in each unit calculated by a pattern multiplication method to solve a mutual coupling correction matrix; using the mutual coupling correction matrix to correct the scattering field of the structure mode item calculated by the pattern multiplication method; adding the scattering field of the antenna mode item and the scattering field of the structure mode item to obtain a scattering field of the array; equivalently constructing the subarray and performing phase compensation to obtain a scattering field of each unit of the large-scale array antenna; and obtaining a total scattering field of the large-scale array antenna and the scattering field of the total antenna mode item and the total structure mode item through field superposition. The application introduces the mutual coupling correction matrix and the subarray theory, avoids directly performing matrix operation on the large-scale array antenna, improves the calculation speed, and solves the problem that a large amount of calculation time and resources are consumed when a scattering field of the large-scale array antenna is obtained in the prior art.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic technology, and specifically relates to a method for obtaining and separating the scattered field of a large-scale array antenna, which can be used to obtain the total scattered field of the large-scale array antenna as well as the scattered field of the antenna mode term and the scattered field of the structural mode term. Background Technology

[0002] Array antennas are a crucial component of radar systems. To reduce their radar cross-section (RCS), researching efficient evaluation methods for the scattering characteristics of large-scale array antennas is of great significance. Current research on the scattering characteristics of array antennas mainly relies on numerical algorithms such as the method of moments (MoM) and the finite element method (FEM), or simulation software based on these algorithms. However, for large-scale array antennas, the computational resources and time consumed by these methods are extremely high. Researching efficient and high-precision calculation and separation methods for the scattered field of large-scale array antennas is of significant engineering importance for analyzing and revealing the scattering characteristics of array antennas at different frequencies and angles, and thus for developing more effective stealth strategies and countermeasures.

[0003] To address the analysis of the scattering characteristics of large-scale array antennas, one approach involves using traditional numerical algorithms or simulation software based on these algorithms to obtain the scattered field. However, when dealing with high-precision solutions for the scattered field of ultra-large-scale array antennas, such as phased array radar antennas with over ten thousand elements, low-frequency algorithms are insufficient due to limitations in computer memory expansion, while high-frequency methods cannot meet the required accuracy. Another approach is to conduct electromagnetic performance verification experiments using small array antennas to support large-scale array design. However, in actual testing, small array experiments often have limitations in data completeness, only providing the total scattered field of the array and failing to obtain the scattered field within each element. Therefore, using these small arrays to accurately extrapolate the electromagnetic performance of large-scale array antennas still faces numerous challenges.

[0004] Patent application CN110737873A, entitled "A Fast Analysis Method for Scattering of Large-Scale Array Antennas," discloses a fast analysis method for the far-field scattered field of a large-scale array antenna. This method performs characteristic mode analysis on the metallic dielectric composite elements, copies the characteristic currents of each element to all elements in the array to form a basis, and uses this basis as a sub-global basis function to expand the equivalent surface current of the array. Utilizing the periodicity and symmetry of the array impedance matrix, a dimension-reduced impedance matrix based on the characteristic mode current expansion is obtained. The matrix equation is then solved using a direct inversion method to finally obtain the array scattering result. However, this method directly establishes the array matrix for calculation. As the array antenna size increases, the matrix dimension also increases, and the time required for matrix operations continuously increases. This method calculates the scattered field of the entire array, only obtaining the scattered field of the array itself, and cannot calculate or separate the scattered field of each element within the array. Furthermore, this method is only suitable for simulation calculations and fails in test scenarios. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to propose a method for acquiring and separating the scattered field of a large-scale array antenna. This method involves acquiring the radiation field in each element of a subarray and calculating the scattered field of the antenna mode terms in each element; using the pattern multiplication method to calculate the scattered field of each element's antenna mode terms and the total antenna mode terms in the array to obtain a mutual coupling correction matrix; using the mutual coupling correction matrix to correct the scattered field of the structural mode terms calculated by the pattern multiplication method; adding the scattered fields of each element's antenna mode terms and the structural mode terms to obtain the total scattered field in the array; performing equivalent construction and phase compensation on the subarray to obtain the scattered field of each element of the large-scale array antenna; and obtaining the total scattered field of the large-scale array antenna and the scattered fields of the total antenna mode terms and the total structural mode terms through field superposition. This method reduces the demand for computational resources, shortens the computation time, and improves the evaluation efficiency of large-scale array antennas. It has advantages such as low computation time and resource consumption, high computational accuracy, and the ability to simultaneously calculate and separate the scattered field.

[0006] To achieve the above technical objectives, the present invention adopts the following technical solution:

[0007] A method for acquiring and separating the scattered field of a large-scale array antenna, comprising the following steps:

[0008] Step 1, from OK In the large-scale array antennas to be solved, adjacent columns are selected. OK The array is used as a subarray, and the radiation field of each element in the subarray is collected. ,in, , , , All are integers, and , , , To measure the pitch angle in a spatial rectangular coordinate system, To measure the azimuth angle in a spatial rectangular coordinate system;

[0009] Step 2: Utilize the radiation fields of each element in the subarray from Step 1. The scattered field of the antenna mode terms in each element of the subarray was calculated. ;

[0010] Step 3: Obtain the antenna mode term scattering field of a single antenna element. Scattering field with structural mode term The scattered field of the antenna mode term of a single antenna element is utilized through the pattern product method. Calculate the scattering field of the antenna mode terms of each element in the subarray. The scattered field of the antenna mode terms in each element of the subarray in step 2. Scattered field of each antenna mode term in the subarray calculated by the product method with the radiation pattern Solve the simultaneous overdetermined equations to obtain the mutual coupling correction matrix. ;

[0011] Step 4: Apply the mutual coupling correction matrix obtained in Step 3. The scattering field of the structural mode term of a single antenna element is obtained by using the pattern product method. Calculated scattering field of each element's structural mode term in the subarray Multiplying the matrices together yields the scattering field of the matrix structure mode term in each element of the subarray. ;

[0012] Step 5: Scatter the antenna mode terms of each element in the subarray. Scattering field with structural mode term The scattered fields in each element of the subarray are obtained by adding them together. :

[0013] ;

[0014] Step 6, OK The subarray of the column is equivalently constructed as OK For a large-scale array antenna, obtain the displacement vector of each element of the subarray relative to the elements of the large-scale array antenna:

[0015]

[0016] in, For subarrays relative to large-scale array antennas The row displacement vector of the row element. For subarrays relative to large-scale array antennas The column displacement vector of the column element. For subarrays relative to large-scale array antennas Line number The total displacement vector of the column element;

[0017] Step 7: Based on Step 6, calculate the first step of the large-scale array antenna. Line number Scattering field of column unit Antenna mode term scattering field and the scattering field of the structure mode term ;

[0018] Step 8: Based on step 7, obtain the total scattered field of the large-scale array antenna. Total antenna mode term scattering field and the scattering field of the overall structure mode term .

[0019] The antenna mode term scattering field in each element of the subarray calculated in step 2 It is expressed as follows:

[0020]

[0021] in, Let be the matrix composed of the radiation fields in each element of the subarray. The number of subarray antenna elements. Here is the load reflection coefficient matrix for each unit. It is the identity matrix. To characterize the mutually coupled S-parameter matrices, To match the received vector, each unit matches the received vector. It is expressed as follows:

[0022]

[0023] in, It is the symbol for imaginary numbers. For wavelength, The amplitude of the incident wave, It is the amplitude vector of the radiation field generated by the antenna element when it is excited. This represents the direction of propagation of the incident plane wave.

[0024] In step 3, the antenna mode term scattering field of a single antenna element is obtained. Scattering field with structural mode term , means as follows:

[0025]

[0026]

[0027] Among them, superscript Represents the scattered field. Indicates the antenna mode item, subscript Indicates the structural pattern item. The reflection coefficient of the antenna element load. For antenna element return loss, The scattered field when an infinite load is connected to the antenna element port. This represents the scattered field when the antenna element port is connected to zero load.

[0028] In step 3, the scattering field of the antenna mode term of a single antenna element is utilized by the pattern product method. The calculated scattering field of each element antenna mode term in the subarray It is expressed as follows:

[0029] Scattered field of each element antenna mode term in bistatic mode :

[0030]

[0031] Scattered field of each element antenna mode term in monostation mode :

[0032]

[0033] in, It is the symbol for imaginary numbers. The scattered wave vector, The incident wave vector, For the first The displacement of each antenna element is expressed as follows:

[0034]

[0035] in, The line spacing vector. This is the column spacing vector.

[0036] In step 3, the scattered field of the antenna mode terms in each element of the subarray is... Scattered field of each antenna mode term in the subarray calculated by the product method with the radiation pattern The simultaneous overdetermined equations are expressed as:

[0037]

[0038] in, The number of subarray antenna elements. The number of sampling points. The mutual coupling correction matrix is ​​represented as A two-dimensional matrix is ​​represented as follows:

[0039]

[0040] in, This represents the inverse matrix.

[0041] In step 4, the scattering field of the structure mode term of a single antenna element is utilized by the pattern product method. The calculated scattering field of each element's structural mode term in the subarray It is expressed as follows:

[0042] Scattering field of each element structure mode term in the bistatic mode :

[0043]

[0044] Scattering field of each element structure mode term in single-station mode :

[0045]

[0046] in, It is the symbol for imaginary numbers. The scattered wave vector, The incident wave vector, For the first The displacement of each antenna element is expressed as follows:

[0047]

[0048] in, The line spacing vector. This is the column spacing vector.

[0049] The mutual coupling correction matrix in step 4 The scattering field of the structural mode term of a single antenna element is obtained by using the pattern product method. Calculated scattering field of each element's structural mode term in the subarray The multiplication of the matrices is represented as follows:

[0050]

[0051] in, The number of subarray antenna elements. The number of sampling points represents the scattering field of the structure mode term in each unit array. It is expressed as follows:

[0052]

[0053] in, The first mutual coupling correction matrix OK.

[0054] In step 6, the subarray is relative to the first large-scale array antenna. Row displacement vector of row element The method to obtain it is as follows:

[0055] (6a) Move the first row of the subarray to the second row. Row unit equivalent to OK The first row to the second row of the column array row unit, to obtain OK The first row to the second row of the column array The displacement vector of each row is ;

[0056] (6b) The first subarray Row unit equivalent to OK The first column array Arriving at the row unit, to obtain OK The array of columns Arriving at the The displacement vector of each row is ,in This is the line spacing;

[0057] (6c) The first subarray Arriving at the Row unit equivalent to OK The first column array Arriving at the row unit, to obtain OK The first column array Arriving at the The displacement vector of each row is ;

[0058] Subarray relative to large-scale array antenna Column displacement vector of column element The method to obtain it is as follows:

[0059] (6d) will OK The first column to the second column of the column array Column cells are equivalent to OK The first column to the second column of the column array column cells, to obtain OK The first column to the second column of the column array The displacement vector of each column is ;

[0060] (6e) will OK Column array Column cells are equivalent to OK Column array Listed to number column cells, to obtain OK The first column array Listed to number The displacement vector of each column is ,in Column spacing;

[0061] (6f) will OK The first column array Listed to number Column cells are equivalent to OK The first column array To the column cells, to obtain OK The first column array Listed to number The displacement vector of each column is .

[0062] The specific method for step 7 is as follows:

[0063] The scattered field was calculated in bistatic mode Antenna mode term scattering field and the scattering field of the structure mode term :

[0064]

[0065]

[0066]

[0067] The scattered field was calculated in single-station mode Antenna mode term scattering field and the scattering field of the structure mode term :

[0068]

[0069]

[0070]

[0071] Among them, superscript Represents the scattered field. It is the symbol for imaginary numbers. The scattered wave vector, The incident wave vector.

[0072] The specific method for step 8 is as follows:

[0073] The total scattered field was calculated in bistatic mode. Total antenna mode term scattering field Total structural mode term scattering field :

[0074]

[0075]

[0076] ;

[0077] The total scattered field was calculated in single-station mode. Total antenna mode term scattering field Total structural mode term scattering field :

[0078]

[0079]

[0080] .

[0081] Compared with the prior art, the present invention has the following advantages:

[0082] First, this invention uses the reciprocity theorem to calculate the scattering field of the antenna mode terms in each element of the subarray using the radiation field in each element of the subarray, which effectively reduces the difficulty of separating the scattering field of the antenna mode terms in the antenna elements of the subarray.

[0083] Second, this invention introduces a mutual coupling correction matrix. By solving the overdetermined equations of the antenna mode term scattering field in each element of the subarray and the antenna mode term scattering field calculated by the pattern product method, the mutual coupling correction matrix is ​​obtained. The scattering field of the structural mode term in each element calculated by the pattern product method is then corrected to obtain the scattering field of the structural mode term in each element array, thus realizing the calculation and separation of the scattering field in each element array.

[0084] Third, this invention combines the theory of array element similarity and spatial phase compensation to simplify the calculation problem of the scattered field of a large-scale array antenna into the calculation problem of the scattered field of a sub-array antenna. It establishes the correspondence between the scattered field in each element of the sub-array and the scattered field in each element of the large-scale array to be solved, and completes the equivalent construction of the large-scale array antenna to be solved. While ensuring the calculation accuracy, it reduces the demand and consumption of computing resources and computing time.

[0085] In summary, this invention has advantages such as low computation time and resource consumption, high computational accuracy, and the ability to simultaneously calculate and separate the scattered field. Attached Figure Description

[0086] Figure 1 This is a flowchart illustrating the implementation of the present invention.

[0087] Figure 2 This is a schematic diagram of a large-scale antenna array for acquiring the scattered field in this invention.

[0088] Figure 3 for Figure 2 The diagram shows a subarray of the antenna array.

[0089] Figure 4 This is a schematic diagram illustrating the row and column equivalence of the subarrays in this invention; wherein, Figure 4 (a) is a diagram illustrating the row equivalent. Figure 4 (b) is a schematic diagram of the column equivalent.

[0090] Figure 5 This is a comparison chart of the calculation results of this invention in bistatic mode with the full-wave simulation results and the calculation results of the pattern product method; wherein, Figure 5 (a) shows a comparison of the total antenna mode scattering results for a large-scale array antenna. Figure 5 (b) shows a comparison of the scattered field results for the overall structure mode term of a large-scale array antenna. Figure 5 (c) shows the comparison of the total scattering field results of the bistatic large-scale array antenna.

[0091] Figure 6 This is a comparison chart of the calculation results of this invention in single-station mode with the full-wave simulation results and the calculation results of the pattern multiplication method; wherein, Figure 6 (a) shows a comparison of the total antenna mode term scattering field results for a single station of a large-scale array antenna. Figure 6 (b) shows a comparison of the scattered field results of the single-station total structural mode term of the large-scale array antenna. Figure 6 (c) shows the comparison of the total scattering field results of a single station of a large-scale array antenna. Detailed Implementation

[0092] To more clearly describe the technical solution and effects of the present invention, the following description is provided in conjunction with specific embodiments and accompanying drawings.

[0093] Reference Figure 1 The implementation steps of this invention are as follows:

[0094] A method for acquiring and separating the scattered field of a large-scale array antenna, comprising the following steps:

[0095] Step 1: Construct a large-scale array antenna.

[0096] Reference Figure 2 This embodiment utilizes Ansys HFSS simulation software to model and simulate the large-scale array antenna to be solved. A microstrip patch antenna is used as the antenna element of the array antenna, and a large-scale array is established in the Cartesian xyz coordinate system. The planar array of elements is used as the large-scale array antenna to be solved. The antenna elements are uniformly arranged, with rows arranged along the positive x-axis and the row spacing being [value missing]. Arranged in columns along the positive y-axis, with a column spacing of [value missing]. The operating frequency is 2.45 GHz, the incident wave is a plane wave, and the incident angle is set to [value missing]. , .

[0097] Step 2: Obtain the radiation field in each element of the subarray. And calculate the antenna mode term scattering field in each element of the subarray. ,in .

[0098] 2.1) Based on the element similarity theory, select elements with the same arrangement as the large-scale array antenna. The element array antenna is used as a subarray, such as Figure 3 As shown;

[0099] 2.2) Set the sampling angle range, pitch angle The range is Sampling interval is azimuth The range is Sampling interval is Obtain the radiation field in each element of the subarray. ;

[0100] 2.3) Using the reciprocity theorem, the radiation field of each element in the subarray is utilized. Calculate the scattered field of the antenna mode terms in each element of the subarray; :

[0101]

[0102] in, Let be the matrix composed of the radiation fields in each element of the subarray. , Here is the load reflection coefficient matrix for each unit. It is the identity matrix. To characterize the mutually coupled S-parameter matrices, To match the received vector, each unit matches the received vector. It is expressed as follows:

[0103]

[0104] in, It is the symbol for imaginary numbers. For wavelength, The amplitude of the incident wave, It is the amplitude vector of the radiation field generated by the antenna element when it is excited. This represents the direction of propagation of the incident plane wave.

[0105] Step 3: Obtain the antenna mode term scattering field of a single antenna element. Scattering field with structural mode term The scattered field of the antenna mode terms in each element of the subarray in step two. The scattered field of the antenna mode term using a single antenna element via the pattern product method Calculated scattering field of antenna mode terms for each element of the subarray Solve the simultaneous overdetermined equations to obtain the mutual coupling correction matrix. .

[0106] 3.1) Simulate the scattering field of a single antenna element, keeping the sampling angle range consistent with the radiation field of each element in the subarray, to obtain the antenna mode term scattering field of the antenna element. Scattering field with structural mode term :

[0107]

[0108]

[0109] Among them, superscript Represents the scattered field. Indicates the antenna mode item, subscript Indicates the structural pattern item. The reflection coefficient of the antenna element load. For antenna element return loss, The scattered field when an infinite load is connected to the antenna element port. The scattered field when the antenna element port is connected to zero load;

[0110] 3.2) The scattered field of each element antenna mode term in the subarray is calculated using the pattern product method. :

[0111] Scattered field of each element antenna mode term in bistatic mode :

[0112]

[0113] Scattered field of each element antenna mode term in monostation mode :

[0114]

[0115] in, It is the symbol for imaginary numbers. The scattered wave vector, The incident wave vector, For the first The displacement of each antenna element is expressed as follows:

[0116]

[0117] in, The line spacing vector. The column spacing vector;

[0118] 3.3) The scattered field of the antenna mode terms in each element of the subarray Scattered field of each antenna mode term in the subarray calculated by the product method with the radiation pattern Simultaneous overdetermined equations:

[0119]

[0120] in, , , The mutual coupling correction matrix is ​​represented as A two-dimensional matrix is ​​represented as follows:

[0121]

[0122] in, This represents the inverse matrix.

[0123] Step 4: Combine the mutual coupling correction matrix with the scattered field from the structure mode term of a single antenna element using the pattern multiplication method. Calculated scattering field of each element's structural mode term in the subarray Multiplying the matrices together yields the scattering field of the structure mode terms in each unit matrix. .

[0124] 4.1) Scattering field of each element's structural mode term obtained by the pattern product method It is expressed as follows:

[0125] Scattering field of each element structure mode term in the bistatic mode :

[0126]

[0127] Scattering field of each element structure mode term in single-station mode :

[0128]

[0129] in, It is the symbol for imaginary numbers. The scattered wave vector, The incident wave vector, For the first The displacement of each antenna element is expressed as follows:

[0130]

[0131] in, The line spacing vector. The column spacing vector;

[0132] 4.2) Mutual Coupling Correction Matrix Scattered field of each element's structural mode term in the subarray calculated by the pattern product method The multiplication of the matrices is represented as follows:

[0133]

[0134] in, The number of subarray antenna elements. The number of sampling points represents the scattering field of the structure mode term in each unit array. It is expressed as follows:

[0135]

[0136] in, The first mutual coupling correction matrix OK.

[0137] Step 5: Based on the results of 2.3) and 4.2), scatter the antenna mode terms in each element of the subarray. Scattering field with structural mode term The scattered fields in each element array are obtained by adding them separately. :

[0138] .

[0139] Step Six: OK The subarray of the column is equivalently constructed as OK For a large-scale array antenna, obtain the displacement vector of each element of the subarray relative to the elements of the large-scale array antenna.

[0140] 6.1) Perform row equivalence on the subarray, transforming the 7x7 subarray into a 10x7 array, such as... Figure 4 As shown in (a), the first large-scale array antenna is obtained. Row displacement vector of row element ;

[0141] 6.1.1) Equip the first to third rows of the subarray with the first to third rows of a 10x7 array, resulting in the displacement vector for each row of the 10x7 array. ;

[0142] 6.1.2) The 4th row of the subarray is equivalent to the 4th to 7th rows of a 10x7 array, resulting in the displacement vector for each row of the 4th to 7th rows of the 10x7 array. ;

[0143] 6.1.3) Equivalently representing rows 5 to 7 of the subarray as rows 8 to 10 of a 10x7 array, the displacement vector for each row of the 10x7 array is: .

[0144] 6.2) Perform column equivalence on the 10x7 array, effectively constructing it as a 10x10 large-scale array antenna, such as... Figure 4 As shown in (b), the first large-scale array antenna is obtained. Column displacement of column element ;

[0145] 6.2.1) The first to third columns of the 10x7 array are equivalent to the first to third columns of a large-scale array antenna, resulting in the displacement vector of each column of the large-scale array antenna as follows: ;

[0146] 6.2.2) The fourth column element of the 10x7 array is equivalent to the fourth to seventh columns of a large-scale array antenna, resulting in the displacement vector of each column from the fourth to the seventh column of the large-scale array antenna. ;

[0147] 6.2.3) The 5th to 7th columns of the 10x7 array are equivalent to the 8th to 10th columns of a large-scale array antenna, resulting in the displacement vector of each column of the 8th to 10th columns of the large-scale array antenna as follows: .

[0148] 6.3) Based on the results of 6.1) and 6.2), the first step of the large-scale array antenna is obtained. Line number Total displacement vector of column element :

[0149] .

[0150] Step 7: Calculate the scattering field of each element of the large-scale array antenna, the scattering field of the antenna mode term, and the scattering field of the structural mode term using the spatial phase compensation theory.

[0151] 7.1) Based on the results of 2.3) and 6.3), the first step of the large-scale array antenna is calculated. Line number Antenna mode term scattering field of column element :

[0152] Antenna mode term scattering field in bistatic mode :

[0153]

[0154] Antenna mode term scattering field in monostation mode :

[0155]

[0156] Among them, superscript Represents the scattered field. It is the symbol for imaginary numbers. The scattered wave vector, The incident wave vector;

[0157] 7.2) Based on the results of 4.2) and 6.3), the first step of the large-scale array antenna is calculated. Line number Scattering field of structural mode terms of column unit :

[0158] Scattering field of structure mode term in bistatic mode :

[0159]

[0160] Scattering field of structure mode terms in single-station mode :

[0161]

[0162] Among them, superscript Represents the scattered field. It is the symbol for imaginary numbers. The scattered wave vector, The incident wave vector;

[0163] 7.3) Based on the results of steps 5 and 6.3), the first step of the large-scale array antenna is calculated. Line number Scattering field of column unit :

[0164] Scattering field in bistatic mode :

[0165]

[0166] Scattering field in single-station mode :

[0167]

[0168] Among them, superscript Represents the scattered field. It is the symbol for imaginary numbers. The scattered wave vector, The incident wave vector.

[0169] Step 8: Obtain the total scattered field of the large-scale array antenna based on the principle of field superposition. Total antenna mode term scattering field and total structure mode term scattering field .

[0170] 8.1) Based on the results in 7.1), the total antenna mode term scattering field of the large-scale array antenna is obtained by superimposing the scattered fields. :

[0171] Total antenna mode term scattering field in bistatic mode :

[0172] ;

[0173] Total antenna mode term scattering field in monostation mode :

[0174] ;

[0175] 8.2) Based on the results in 7.2), the scattered field of the overall structural mode term of the large-scale array antenna is obtained by superimposing the scattered fields. :

[0176] Total structural mode term scattering field in bistatic mode :

[0177] ;

[0178] Total structural mode term scattering field in single-station mode :

[0179] ;

[0180] 8.3) Based on the results in 7.3), the total scattered field of the large-scale array antenna is obtained by superimposing the scattered fields. :

[0181] Total scattering field in bistatic mode :

[0182] .

[0183] Total scattering field in single-station mode :

[0184] .

[0185] The effects of this invention can be further illustrated by the following simulation experiments:

[0186] I. Simulation Experiment Conditions

[0187] Ansys HFSS simulation software was used to model and simulate the large-scale array antenna to be solved. Microstrip patch antennas were used as the antenna elements of the array antenna. A large-scale array antenna was established in a Cartesian xyz coordinate system. A planar array of elements is used as a large-scale array antenna to acquire the scattered field. The antenna elements are uniformly arranged, with those along the plane... The rows are arranged along the positive axis, with a row spacing of [value missing]. Arranged in columns along the positive y-axis, with a column spacing of [value missing]. The operating frequency is 2.45GHz. Sampling parameters are set at the spatial pitch angle. for spatial azimuth for Obtain total scattered field data of a large-scale array antenna within a certain range, and select antennas with the same arrangement as the large-scale array antenna. The element array antenna is used as a subarray, and the radiation field data of each element in the subarray is acquired. Finally, the scattering field data of a single antenna element is acquired.

[0188] II. Simulation Experiment Content

[0189] Simulation Experiment 1: Under the above experimental conditions, the method of this invention uses the radiation field data of each element in the subarray and the bistatic scattering field data of the antenna element to obtain the scattering field of a large-scale array antenna in bistatic mode. The results are compared with those obtained by directly simulating the large-scale array antenna using HFSS and by calculating the results using the pattern product method. The results are as follows: Figure 5 As shown. Wherein:

[0190] Figure 5(a) shows a comparison of the total antenna mode scattering results for a large-scale array antenna. Figure 5 (b) shows a comparison of the scattered field results for the overall structure mode term of a large-scale array antenna. Figure 5 (c) Comparison of total scattering field results for bistatic large-scale array antennas.

[0191] from Figure 5 of (a) Figure 5 of (b) Figure 5 As shown in (c), the bistatic scattering field of the large-scale array antenna calculated by this invention in bistatic mode is in better agreement with the HFSS simulation results compared to the pattern product method. Furthermore, the antenna mode term scattering field calculated by this invention is basically consistent with the HFSS simulation results, showing good agreement; the main lobe region and the first and second sidelobe regions of the structural mode term scattering field are basically consistent, with the error only showing a small increasing trend with angular deviation outside the second sidelobe region; the main lobe region and the first and second sidelobe regions of the total scattering field are basically consistent, with the error only showing a small increasing trend with angular deviation outside the second sidelobe region, indicating that this invention can achieve the acquisition and separation of the scattering field of a large-scale array antenna. Moreover, this invention only needs to acquire the subarray radiation field data and the bistatic antenna mode term scattering field and structural mode term scattering field of a single antenna element, requiring far less computation time and resources than directly simulating the bistatic scattering field of a large-scale array antenna.

[0192] Simulation Experiment 2: Under the above experimental conditions, the method of this invention uses the radiation field data of each element in the subarray and the single-station scattering field data of the antenna element to obtain the scattering field of a large-scale array antenna in monostatic mode. The results are compared with those obtained by directly simulating the large-scale array antenna using HFSS and by calculating the results using the pattern product method. The results are as follows: Figure 6 As shown. Wherein:

[0193] Figure 6 (a) shows a comparison of the total antenna mode term scattering field results for a single station of a large-scale array antenna. Figure 6 (b) shows a comparison of the scattered field results of the single-station total structural mode term of the large-scale array antenna. Figure 6 (c) shows the comparison of the total scattering field results of a single station of a large-scale array antenna.

[0194] from Figure 6 of (a) Figure 6 of (b) Figure 6 As can be seen from (c), in monostatic mode, the monostatic scattering field of the large-scale array antenna calculated by this invention is in better agreement with the HFSS simulation results compared to the pattern product method. Furthermore, the antenna mode term scattering field calculated by this invention is basically consistent with the HFSS simulation results, showing good agreement; the structural mode term scattering field... The results within the angular domain are basically consistent with those of the HFSS simulation, while smaller errors exist in other angular domains; the total scattered field is... The results are largely consistent with HFSS simulations in the angular domain, with smaller errors observed in other angular domains, indicating that this invention can achieve the acquisition and separation of the scattered field of a large-scale array antenna. Furthermore, this invention only requires acquiring the subarray radiation field data and the monostatic antenna mode term scattered field and structural mode term scattered field of a single antenna element, requiring significantly less computation time and resources than directly simulating the monostatic scattered field of a large-scale array antenna.

Claims

1. A method for acquiring and separating the scattered field of a large-scale array antenna, characterized in that: The specific steps include: Step 1, from OK In the large-scale array antennas to be solved, adjacent columns are selected. OK The array is used as a subarray, and the radiation field of each element in the subarray is collected. ,in, , , , All are integers, and , , , To measure the pitch angle in a spatial rectangular coordinate system, To measure the azimuth angle in a spatial rectangular coordinate system; Step 2: Utilize the radiation fields of each element in the subarray from Step 1. The scattered field of the antenna mode terms in each element of the subarray was calculated. ; Step 3: Obtain the antenna mode term scattering field of a single antenna element. Scattering field with structural mode term The scattered field of the antenna mode term of a single antenna element is utilized through the pattern product method. Calculate the scattering field of the antenna mode terms of each element in the subarray. The scattered field of the antenna mode terms in each element of the subarray in step 2. Scattered field of each antenna mode term in the subarray calculated by the product method with the radiation pattern Simultaneous overdetermined equations: Solve the mutual coupling correction matrix ;in, The number of subarray antenna elements. The number of sampling points; Step 4: Apply the mutual coupling correction matrix obtained in Step 3. The scattering field of the structural mode term of a single antenna element is obtained by using the pattern product method. Calculated scattering field of each element's structural mode term in the subarray Multiplying the matrices together yields the scattering field of the matrix structure mode term in each element of the subarray. ; Step 5: Scatter the antenna mode terms of each element in the subarray. Scattering field with structural mode term The scattered fields in each element of the subarray are obtained by adding them together. : ； Step 6, OK The subarray of the column is equivalently constructed as OK For a large-scale array antenna, obtain the displacement vector of each element of the subarray relative to the elements of the large-scale array antenna: in, For subarrays relative to large-scale array antennas The row displacement vector of the row element. For subarrays relative to large-scale array antennas The column displacement vector of the column element. For subarrays relative to large-scale array antennas Line number The total displacement vector of the column element; Subarray relative to large-scale array antenna Row displacement vector of row element The method for obtaining it is as follows: (6a) Move the first row of the subarray to the second row. Row unit equivalent to OK The first row to the second row of the column array row unit, to obtain OK The first row to the second row of the column array The displacement vector of each row is ; (6b) The first subarray Row unit equivalent to OK The first column array Arriving at the row unit, to obtain OK The array of columns Arriving at the The displacement vector of each row is ,in This is the line spacing; (6c) The first subarray Arriving at the Row unit equivalent to OK The first column array Arriving at the row unit, to obtain OK The first column array Arriving at the The displacement vector of each row is ; Subarray relative to large-scale array antenna Column displacement vector of column element The acquisition method and subarray relative to the first large-scale array antenna Row displacement vector of row element The same, only the object being operated on has changed to a column; Step 7: Based on Step 6, calculate the first step of the large-scale array antenna. Line number Scattering field of column unit Antenna mode term scattering field and the scattering field of the structure mode term ; Step 8: Based on step 7, obtain the total scattered field of the large-scale array antenna. Total antenna mode term scattering field and the scattering field of the overall structure mode term .

2. The method for acquiring and separating the scattered field of a large-scale array antenna according to claim 1, characterized in that, Step 2 calculates the antenna mode term scattering field in each element of the subarray. It is expressed as follows: in, Let be the matrix composed of the radiation fields in each element of the subarray. The number of subarray antenna elements. Here is the load reflection coefficient matrix for each unit. It is the identity matrix. To characterize the mutually coupled S-parameter matrices, To match the received vector, each unit matches the received vector. It is expressed as follows: in, It is the symbol for imaginary numbers. For wavelength, The amplitude of the incident wave, It is the amplitude vector of the radiation field generated by the antenna element when it is excited. This represents the direction of propagation of the incident plane wave.

3. The method for acquiring and separating the scattered field of a large-scale array antenna according to claim 1, characterized in that, Step 3 involves obtaining the antenna mode term scattering field of a single antenna element. Scattering field with structural mode term , means as follows: Among them, superscript Represents the scattered field. Indicates the antenna mode item, subscript Indicates the structural pattern item. The reflection coefficient of the antenna element load. For antenna element return loss, The scattered field when an infinite load is connected to the antenna element port. This represents the scattered field when the antenna element port is connected to zero load.

4. The method for acquiring and separating the scattered field of a large-scale array antenna according to claim 1, characterized in that, In step 3, the scattered field of the antenna mode term of a single antenna element is utilized through the pattern product method. The calculated scattering field of each element antenna mode term in the subarray It is expressed as follows: Scattered field of each element antenna mode term in bistatic mode : Scattered field of each element antenna mode term in monostation mode : in, It is the symbol for imaginary numbers. The scattered wave vector, The incident wave vector, For the first The displacement of each antenna element is expressed as follows: in, The line spacing vector. This is the column spacing vector.

5. The method for acquiring and separating the scattered field of a large-scale array antenna according to claim 1, characterized in that, Mutual coupling correction matrix in step 3 C for A two-dimensional matrix is ​​represented as follows: in, This represents the inverse matrix.

6. The method for acquiring and separating the scattered field of a large-scale array antenna according to claim 1, characterized in that, In step 4, the scattered field of the structural mode term of a single antenna element is utilized through the pattern product method. The calculated scattering field of each element's structural mode term in the subarray It is expressed as follows: Scattering field of each element structure mode term in the bistatic mode : Scattering field of each element structure mode term in single-station mode : in, It is the symbol for imaginary numbers. The scattered wave vector, The incident wave vector, For the first The displacement of each antenna element is expressed as follows: in, The line spacing vector. This is the column spacing vector.

7. The method for acquiring and separating the scattered field of a large-scale array antenna according to claim 1, characterized in that, Mutual coupling correction matrix in step 4 The scattering field of the structural mode term of a single antenna element is obtained by using the pattern product method. Calculated scattering field of each element's structural mode term in the subarray The multiplication of the matrices is represented as follows: in, The number of subarray antenna elements. The number of sampling points represents the scattering field of the structure mode term in each unit array. It is expressed as follows: in, The first mutual coupling correction matrix OK.

8. The method for acquiring and separating the scattered field of a large-scale array antenna according to claim 1, characterized in that, The specific method for step 7 is as follows: The scattered field was calculated in bistatic mode Antenna mode term scattering field and the scattering field of the structure mode term : The scattered field was calculated in single-station mode Antenna mode term scattering field and the scattering field of the structure mode term : Among them, superscript Represents the scattered field. It is the symbol for imaginary numbers. The scattered wave vector, The incident wave vector.

9. The method for acquiring and separating the scattered field of a large-scale array antenna according to claim 1, characterized in that, The specific method for step 8 is as follows: The total scattered field was calculated in bistatic mode. Total antenna mode term scattering field Total structural mode term scattering field : The total scattered field was calculated in single-station mode. Total antenna mode term scattering field Total structural mode term scattering field : 。

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