A method and device for extracting electromagnetic coupling parameters based on multi-layer fast multipole

Abstract

The present invention discloses a method and device for extracting electromagnetic coupling parameters based on multi-layer fast multipole, including: constructing an electromagnetic model of a radar geometric model; obtaining a basis function index table of the radar geometric model; according to the basis function index table, using a preset algorithm to calculate the current and magnetic flow distribution corresponding to the excitation of the first antenna unit when the first antenna unit is excited, and extracting the first typical characteristic current and magnetic flow of the radar geometric model; according to the first typical characteristic current and magnetic flow of the radar geometric model, as the initial solution of the solver, calculating the current and magnetic flow distribution corresponding to the excitation of the antenna unit adjacent to the first antenna unit when the antenna unit adjacent to the first antenna unit is excited; until all antenna units are excited, the current and magnetic flow distribution corresponding to the excitation of all antenna units are obtained, and the S parameters or unit directivity diagrams of the antenna array of the radar geometric model are extracted. The present invention can improve the efficiency of calculating large antenna arrays and carrier computing resources.

Description

Technical Field

[0001] The invention belongs to the technical field of electromagnetics, and in particular relates to a method and a device for extracting electromagnetic coupling parameters based on a multi-layer fast multipole. Background Art

[0002] Array antennas are widely used in long-range early warning radars, airborne radars and other fields. When designing and optimizing array antennas, it is necessary to extract the S parameters of the array antenna for isolation analysis and extract the unit radiation pattern of the array for optimization.

[0003] At present, the common method is to use the method of moments (MoM) or the finite element method (FEM) to simulate the antenna array as a whole, and then extract the S parameters or unit radiation pattern of the array. Although this method has high calculation accuracy, it requires a lot of computing resources and time resources when performing simulation calculations; and with the increasing frequency of array antennas and the increasing size of arrays in actual engineering, the demand for integrated simulation design of array antenna loads is increasing, and the computing resources consumed by using MoM or FEM methods for simulation calculations have become unacceptable. Therefore, it is urgent to provide an electromagnetic coupling parameter extraction method that can improve the accurate and efficient simulation of large antenna arrays under limited computing resources. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a method and device for extracting electromagnetic coupling parameters based on multi-layer fast multipole. The technical problem to be solved by the present invention is achieved by the following technical solutions:

[0005] In a first aspect, the present invention provides a method for extracting electromagnetic coupling parameters based on multi-layer fast multipole, comprising:

[0006] Constructing an electromagnetic model of a radar geometric model; the radar geometric model includes an array antenna and a carrier platform geometric model and a wave port excitation model, and the array antenna includes multiple antenna units;

[0007] According to the electromagnetic model, a basis function index table of the radar geometric model is obtained; the basis function of the radar geometric model includes basis function information of the antenna unit and basis function information of the carrier platform;

[0008] According to the basis function index table, a preset algorithm is used to calculate the current and magnetic current distribution corresponding to the excitation of the first antenna unit when the first antenna unit is excited;

[0009] Extracting the first typical characteristic current and magnetic current of the radar geometric model according to the current and magnetic current distribution corresponding to the excitation of the first antenna unit;

[0010] According to the first typical characteristic current and magnetic current of the radar geometric model, as the initial solution of the solver, when the antenna unit adjacent to the first antenna unit is excited, the current and magnetic current distribution corresponding to the excitation of the antenna unit adjacent to the first antenna unit is calculated;

[0011] Until all antenna units are excited, the current and magnetic current distribution corresponding to the excitation of all antenna units are obtained;

[0012] According to the current and magnetic flow distribution corresponding to the excitation of all antenna units, the S parameters or unit radiation pattern of the antenna array of the radar geometric model are extracted.

[0013] In a second aspect, the present invention further provides an electromagnetic coupling parameter extraction device based on a multi-layer fast multipole, comprising:

[0014] An electromagnetic model building module is used to build an electromagnetic model of a radar geometric model; the radar geometric model includes an array antenna and a carrier platform geometric model and a wave port excitation model, and the array antenna includes a plurality of antenna units;

[0015] A basis function index table acquisition module is used to acquire a basis function index table of a radar geometric model according to an electromagnetic model; the basis function of the radar geometric model includes basis function information of an antenna unit and basis function information of a carrier platform;

[0016] A current and magnetic current distribution acquisition module is used to calculate the current and magnetic current distribution corresponding to the excitation of the first antenna unit when the first antenna unit is excited using a preset algorithm according to the basis function index table;

[0017] A typical characteristic current and magnetic current acquisition module is used to extract the first typical characteristic current and magnetic current of the radar geometric model according to the current and magnetic current distribution corresponding to the excitation of the first antenna unit;

[0018] A current and magnetic current updating module, used for calculating the current and magnetic current distribution corresponding to the excitation of the antenna unit adjacent to the first antenna unit when the antenna unit adjacent to the first antenna unit is excited, based on the first typical characteristic current and magnetic current of the radar geometric model as the initial solution of the solver;

[0019] An iteration module is used to excite all antenna units and obtain the current and magnetic current distribution corresponding to the excitation of all antenna units;

[0020] The result output module is used to extract the S parameters or unit radiation pattern of the antenna array of the radar geometric model according to the current and magnetic current distribution corresponding to the excitation of all antenna units.

[0021] Beneficial effects of the present invention:

[0022] The invention provides a method and device for extracting electromagnetic coupling parameters based on multi-layer fast multipole, which construct an electromagnetic model of a radar geometric model, and according to the electromagnetic model, use a wave port modeling technology to better simulate antenna excitation and realize load matching, and calculate more accurate electromagnetic coupling characteristics, namely S parameters; construct a basis function index table of the radar geometric model, and use a multi-layer fast multipole algorithm to calculate the current and magnetic flow distribution corresponding to the first antenna unit excitation when the radar geometric model is excited, so as to solve larger-scale problems under limited computing resources; construct an initial solution of a solver according to the current and magnetic flow distribution corresponding to the first antenna unit excitation, which can effectively reduce the number of iteration steps when an iterative algorithm such as multi-layer fast multipole is used to calculate multiple excitation problems such as sequential excitation of array antennas, thereby achieving the purpose of reducing computing time and improving efficiency; through continuous iterative updating of the solver, the current and magnetic flow distribution corresponding to the excitation of all antenna units are obtained, and the S parameters or unit radiation patterns of the antenna array are further obtained; the invention is used to solve the problem that the computing resources and computing time consumption are too large when calculating a large antenna array load in the prior art, resulting in the inability to calculate, and the technical problem that too many array antenna excitations lead to low computing efficiency of the multi-layer fast multipole method.

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a flow chart of a method for extracting electromagnetic coupling parameters based on multi-layer fast multipole provided by an embodiment of the present invention;

[0025] Figure 2 is a schematic diagram of a radar geometric model provided by an embodiment of the present invention;

[0026] Figure 3 is a schematic diagram of an array antenna provided by an embodiment of the present invention;

[0027] Figure 4 is a schematic diagram of current distribution of the antenna array when the test model provided by the embodiment of the present invention is excited by the rectangular wave port 3;

[0028] Figure 5 is a schematic diagram of current distribution of the antenna array when the test model provided by the embodiment of the present invention is excited by the rectangular wave port 2;

[0029] Figure 6 It is a schematic diagram of the initial solution current distribution for constructing rectangular wave port 2 excitation provided by an embodiment of the present invention;

[0030] Figure 7 is a comparison diagram of S parameter results of the antenna array plus radome test model provided by an embodiment of the present invention;

[0031] Figure 8 It is a comparison diagram of the radiation pattern xoz surface results of the antenna array plus radome test model provided in an embodiment of the present invention;

[0032] Fig. 9 It is a comparison diagram of the radiation pattern yoz surface results of the antenna array plus radome test model provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0034] In the prior art, the multilevel fast multipole algorithm (MLFMA) method, as a fast algorithm of MoM, can reduce the computational complexity to O(NlogN) and greatly reduce the required computing resources. Therefore, the use of MLFMA can achieve accurate and efficient simulation calculations for large antenna arrays. However, the current academic research on MLFMA is mostly focused on using MLFMA to calculate the electromagnetic scattering characteristics of electrically large ideal conductor targets, and there is less research on the calculation of electromagnetic radiation characteristics of complex structures such as array antennas that contain metals and a variety of dielectric materials. Among them, Fritz Arndt, J. Brandt et al. published an article titled "Fast CAD and optimization of waveguide components and aperture antennas by hybrid MM / FE / MoM / FD methods-State-of-the-art and recent advances" in the journal IEEE Transactions on Microwave Theory and Techniques, Vol. 52, No. 1, pp. 292-305 in 2004, in which they disclosed a waveport excitation modeling method based on the mode matching method. This method achieves the effect of simulating matching loads and absorbing echoes in the waveguide by connecting a semi-infinite waveguide structure to the waveport surface, and establishes the integral equation of the port based on the equivalent principle, thereby realizing the simulation calculation of the electromagnetic radiation problem of the antenna model by MLFMA. In 2008, Jan Fostier and Femke Olyslager published an article titled "An Asynchronous Parallel MLFMA for Scattering at Multiple Dielectric Objects" in the journal IEEE Transactions on Antennas and Propagation, Vol. 56, No. 8, pp. 2346-2355. They disclosed a parallel MLFMA method for calculating multi-media structure scattering problems. This method uses an asynchronous parallel strategy based on a message passing interface (MPI) to implement MLFMA calculations for models with complex structures.Although the above method can realize the extraction of S parameters and unit radiation patterns of array antennas by MLFMA, its shortcomings are: although MLFMA can effectively reduce the memory requirements and calculation time when calculating array antennas, as an iterative method, when calculating multi-excitation problems such as array antenna S parameters and unit radiation pattern extraction, it is necessary to perform an iterative calculation when calculating each set of excitations. Therefore, the more antenna units the array antenna has, the more times MLFMA performs iterative calculations, the longer the calculation time required and the impact on the final calculation efficiency.

[0035] In view of this, the present invention provides an electromagnetic coupling parameter extraction method based on multi-layer fast multipole, which is used to solve the problem in the prior art that the computing resources and computing time are too large to be calculated when calculating large antenna arrays and carriers, and the technical problem that the multi-layer fast multipole method has low calculation efficiency due to too many array antenna excitations.

[0036] See also Figure 1 to Figure 3 , Figure 1 is a flow chart of a method for extracting electromagnetic coupling parameters based on multi-layer fast multipole provided by an embodiment of the present invention. Figure 2 is a schematic diagram of a radar geometric model provided by an embodiment of the present invention, Figure 3 is a schematic diagram of an array antenna provided by an embodiment of the present invention. The present invention provides an electromagnetic coupling parameter extraction method based on a multi-layer fast multipole, including:

[0037] S101, constructing an electromagnetic model of a radar geometric model; the radar geometric model includes an array antenna and a carrier platform geometric model and a wave port excitation model, and the array antenna includes a plurality of antenna units.

[0038] Specifically, in this embodiment, the electromagnetic model includes an antenna array and a carrier platform electromagnetic model, and a wave port excitation electromagnetic model; wherein,

[0039] The process of building the electromagnetic model of the antenna array and carrier platform includes:

[0040] The electric field integral equation and PMCHW integral equation are used to discretize the geometric model of the array antenna and the carrier platform and establish an electromagnetic model to obtain the electromagnetic model of the antenna array and the carrier platform; wherein, for different regions i and j, the electric field integral equation and PMCHW integral equation are expressed as follows:

[0041]

[0042] in, represents the unit normal vector of the interface from region j to region i, E( j ) represents the electric field in region j, E( i) represents the electric field in region i, η i represents the wave impedance of region i, L( i ) and K( i ) represents the integral operator of region i, J i represents the discrete equivalent current in region i at the interface, M i represents the discrete equivalent magnetic flux in region i at the interface, η j represents the wave impedance of region j, L( j ) and K( j ) represents the integral operator of region j, J j represents the discrete equivalent current in region j at the interface, M j represents the discrete equivalent magnetic flux in region j at the interface, H( j ) represents the magnetic field in region j, H( i ) represents the magnetic field in region i.

[0043] The process of building the wave port excitation electromagnetic model includes:

[0044] The wave port excitation is discretized in the wave port excitation model using a preset integral equation and electromagnetic modeling is established to obtain the wave port excitation electromagnetic model; wherein the preset integral equation expression is:

[0045]

[0046] in, represents the unit normal vector on the port surface from the wave port to the waveguide cavity, J s Represents the equivalent current on the wave port, M s represents the equivalent magnetic current on the wave port, e l represents the lth mode field in the wave port excitation, e j represents the normalized eigenvector of the waveguide, η j represents the wave impedance in the waveguide, and S represents the port surface.

[0047] It should be noted that the present embodiment uses a wave port model to simulate antenna excitation. The wave port model can effectively simulate antenna excitation while achieving the effect of matching the load, and can more accurately extract the S parameters of the antenna array.

[0048] S102. Obtain a basis function index table of a radar geometric model according to the electromagnetic model; the basis function of the radar geometric model includes basis function information of antenna units and basis function information of a carrier platform.

[0049] Specifically, in this embodiment, the relative positions between the antenna units are recorded, and the basis function information of each antenna unit is marked to establish a basis function index table of the antenna unit; at the same time, the basis function information of the carrier platform is marked, and the basis function information of the carrier platform is recorded in the basis function index table; through the above method, the basis function index table of the radar geometric model is constructed.

[0050] S103. When the first antenna unit is excited, the current and magnetic current distribution corresponding to the excitation of the first antenna unit are calculated using a preset algorithm according to the basis function index table.

[0051] Specifically, in this embodiment, the preset algorithm is MLFMA, and any antenna unit in the array antenna is selected, and MLFMA is used to calculate the solution when the antenna unit is excited and other antenna units are not excited, and the current and magnetic flow distribution of the radar geometric model are obtained according to the solution, wherein the expression of the current and magnetic flow distribution I of the radar geometric model is:

[0052]

[0053] Among them, I s represents the equivalent current and magnetic flow corresponding to the carrier platform basis function, represents the equivalent current and magnetic current corresponding to the kth antenna unit basis function, represents the equivalent current and magnetic current corresponding to the wave port excitation of the antenna unit, k represents the index of the antenna unit, and N represents the total number of antenna units.

[0054] Compared with the prior art which uses the method of moments, the finite element method, etc. to extract the S parameters of a large antenna array, this embodiment uses a multi-layer fast multipole algorithm, which can effectively reduce the consumption of computing resources such as memory, so that it is possible to solve the problems of larger-scale antenna arrays and carrier platforms with limited resources.

[0055] S104. Extracting the first typical characteristic current and magnetic current of the radar geometric model according to the current and magnetic current distribution corresponding to the excitation of the first antenna unit.

[0056] Specifically, in this embodiment, the detailed process of step S104 includes:

[0057] According to the current and magnetic current distribution of the radar geometric model, the S parameters of the radar geometric model are obtained;

[0058] According to the S parameters of the radar geometric model, the first typical characteristic current and magnetic current of the radar geometric model are extracted.

[0059] The first typical characteristic current and magnetic current I of the radar geometric model typ The expression is:

[0060]

[0061] Among them, T s represents the threshold for extracting typical characteristic current and magnetic current, m represents the number of the selected antenna unit, S 1,m It represents the S parameter, i.e., coupling parameter, between the antenna unit currently being solved and the mth antenna unit. Optionally, based on actual engineering experience, the threshold for extracting typical characteristic current and magnetic current is usually -20 dB to -30 dB.

[0062] S105. Using the first typical characteristic current and magnetic current of the radar geometric model as the initial solution of the solver, calculate the current and magnetic current distribution corresponding to the excitation of the antenna unit adjacent to the first antenna unit when the antenna unit adjacent to the first antenna unit is excited.

[0063] Specifically, in this embodiment, when the antenna units adjacent to the first antenna unit are excited, the current and magnetic flow distribution corresponding to the excitation of the antenna units adjacent to the first antenna unit are calculated in sequence; optionally, the first antenna unit is the middle antenna unit in the array antenna, and the selection of the middle antenna unit of the array as the first calculated antenna unit is based on actual engineering experience, so that the most antenna units with the strongest coupling with the excited antenna units can be obtained, that is, when extracting the typical characteristic current and magnetic flow in step S104, the middle antenna unit of the antenna array is used as the first calculated unit, satisfying S 1,m >T s The antenna unit is the largest, and the typical characteristic electromagnetic current obtained is also the most representative.

[0064] Optionally, the solver's initial solution expression is:

[0065]

[0066] Among them, I con Represents the first typical characteristic electric current and magnetic current.

[0067] It should be noted that, according to the established basis function index table, according to the relative position relationship between the currently excited antenna unit and the surrounding antenna units, the first typical characteristic current and magnetic current are assigned to the corresponding position to complete the construction of the initial solution. Traditional initial solution construction methods are mostly used to solve scattering problems, and are not applicable to solving antenna array radiation and coupling problems. In this embodiment, a method for constructing an initial solution is proposed, which can effectively reduce the number of iterations when the iterative solver reaches the convergence accuracy when sequentially exciting the multiple types of excitation problems such as antenna arrays, and can improve the efficiency of the iterative method for solving antenna multi-excitation problems.

[0068] S106: until all antenna units are excited, the current and magnetic current distribution corresponding to the excitation of all antenna units are obtained.

[0069] Specifically, in this embodiment, exciting all antenna units includes two forms:

[0070] One is: the antenna units other than the first antenna unit all use the first typical characteristic current and magnetic current as the initial solution of the solver, and when the antenna units other than the first antenna unit are excited, the current and magnetic current distribution corresponding to the excitation of all the antenna units are calculated;

[0071] The other is: the second antenna unit adjacent to the first antenna unit uses the first typical characteristic current and magnetic current as the initial solution of the solver to calculate the current and magnetic current distribution corresponding to the excitation of the second antenna unit when the second antenna unit is excited; according to the current and magnetic current distribution corresponding to the excitation of the second antenna unit, the second typical characteristic current and magnetic current of the radar geometric model are extracted, and the third antenna unit adjacent to the second antenna unit uses the second typical characteristic current and magnetic current as the initial solution of the solver to calculate the excitation time of the third antenna unit and the current and magnetic current distribution corresponding to the excitation of the third antenna unit; until all antenna units are excited, the current and magnetic current distribution corresponding to the excitation of all antenna units are obtained.

[0072] S107. Extract the S parameters or unit radiation pattern of the antenna array of the radar geometric model according to the current and magnetic current distribution corresponding to the excitation of all antenna units.

[0073] In summary, the present invention provides an electromagnetic coupling parameter extraction method based on multi-layer fast multipole, constructs an electromagnetic model of a radar geometric model, and according to the electromagnetic model, uses wave port modeling technology to better simulate antenna excitation and realize load matching, and calculates more accurate electromagnetic coupling characteristics, namely S parameters; constructs a basis function index table of the radar geometric model, and uses the multi-layer fast multipole algorithm to calculate the current and magnetic flux distribution corresponding to the first antenna unit excitation when the radar geometric model is excited, so that larger-scale problems can be solved under limited computing resources; constructs the initial solution of the solver according to the current and magnetic flux distribution corresponding to the first antenna unit excitation, which can effectively reduce the number of iteration steps when the multi-layer fast multipole iterative algorithm such as the multi-layer fast multipole calculates multiple excitation problems such as sequential excitation of array antennas, thereby achieving the purpose of reducing the calculation time and improving the efficiency; through the continuous iterative update of the solver, the current and magnetic flux corresponding to the excitation of all antenna units are obtained, and the S parameters or unit radiation patterns of the antenna array are further obtained; the present invention is used to solve the problem that the computing resources and computing time consumption are too large when calculating the load on a large antenna array in the prior art, resulting in the inability to calculate, and the technical problem that the multi-layer fast multipole method has low calculation efficiency due to too many array antenna excitations.

[0074] In an optional embodiment of the present invention, the electromagnetic coupling parameter extraction method based on multi-layer fast multipole of the present invention is described by the following content, specifically:

[0075] S1. Establish an electromagnetic model of the array antenna loading platform.

[0076] According to the structural properties of the antenna unit and the carrier platform, the corresponding integral equations are used for discretization, an electromagnetic model of the array antenna carrier platform is established, and the wave port model is used to model the antenna excitation.

[0077] Figure 2 and Figure 3 A schematic diagram of an antenna array plus radome model is given.

[0078] S2. Construct a basis function index table of antenna units and carrier platforms.

[0079] According to the relative position relationship between antenna units in the antenna array, the correspondence between the antenna unit structure, the antenna unit wave port excitation, and the discrete basis function of the radome structure is constructed, and the corresponding index table is established.

[0080] S3. Calculate the solution when the antenna unit in the array is excited, and then obtain the electric and magnetic current distribution of the antenna array and the antenna cover when the antenna unit is excited.

[0081] First, select a typical antenna unit excitation solution. In this case, select the antenna array position, that is, antenna unit 3. Figure 4 A schematic diagram of the current distribution of the antenna array when antenna unit 3 is excited is given.

[0082] S4. Extract typical characteristic electric and magnetic currents according to the solution obtained in step S3.

[0083] According to the solution obtained in step S3, combined with the basis function index table constructed in step S2 and the S parameters obtained by exciting the antenna unit in step S3, typical characteristic electric and magnetic currents are extracted.

[0084] S5 constructs an initial solution when the adjacent antenna unit is excited based on the typical characteristic electric and magnetic currents extracted in step S4.

[0085] Construct the initial solution when exciting the adjacent antenna unit. In this case, the adjacent antenna unit selected is antenna unit 2. For comparison, in this case, Figure 5 The current distribution diagram of the antenna array when antenna unit 2 is excited is given. Figure 6 The schematic diagram of the antenna array current distribution corresponding to the initial solution when the antenna unit 2 constructed by the method of the present invention is excited is given. Figure 5 as well as Figure 6 It can be seen that the initial solution constructed by the method of the present invention can obtain a current distribution similar to its true solution.

[0086] S6. Calculate the solution when the adjacent antenna unit is excited.

[0087] The initial solution obtained in step S5 is brought into the iterative solver to calculate the solution when antenna unit 2 is excited.

[0088] S7. Determine whether the calculation of all antenna units is completed.

[0089] It is determined whether the calculation of all antenna units is completed. If not, steps S5, S6, and S7 are repeated until the calculation of all antenna units when excited is completed. Table 1 shows the number of iterations required for the antenna array plus antenna cover to calculate all antenna units under excitation in this case. In the table, * represents the solution of the antenna unit for extracting typical characteristic electric and magnetic currents. It can be seen from Table 1 that the traditional initial solution construction method is not suitable for solving the antenna array coupling problem. The method of the present invention can effectively reduce the number of iterations required for solving the antenna array coupling problem and improve the algorithm calculation efficiency.

[0090] Table 1 Comparison of the number of iterations required for calculating different rectangular port excitations by the method of the present invention and the traditional method

[0091]

[0092]

[0093] S8. Extract S parameters or unit orientation patterns.

[0094] After completing the calculation of all antenna elements, extract the antenna array S parameters or element radiation pattern for antenna design, optimization, etc. Figure 6 and Figure 7 The S parameters of the antenna array plus radome model and the two-dimensional radiation pattern calculation results of the xoz and yoz planes when the five antenna units are excited in the same direction with equal amplitude are given by the addition theorem. It can be seen from the figure that the calculation results of the method of the present invention are in good agreement with those of the commercial software, which verifies the calculation accuracy of the technology of the present invention.

[0095] Based on the same inventive concept, the present invention also provides an electromagnetic coupling parameter extraction device based on multi-layer fast multipole, which is applied to an electromagnetic coupling parameter extraction method based on multi-layer fast multipole provided in the above embodiment of the present invention. The embodiment of the method is referred to above and will not be repeated here; the device comprises:

[0096] An electromagnetic model building module is used to build an electromagnetic model of a radar geometric model; the radar geometric model includes an array antenna and a carrier platform geometric model and a wave port excitation model, and the array antenna includes a plurality of antenna units;

[0097] A basis function index table acquisition module is used to acquire a basis function index table of a radar geometric model according to an electromagnetic model; the basis function of the radar geometric model includes basis function information of an antenna unit and basis function information of a carrier platform;

[0098] A current and magnetic current distribution acquisition module is used to calculate the current and magnetic current distribution corresponding to the excitation of the first antenna unit when the first antenna unit is excited using a preset algorithm according to the basis function index table;

[0099] A typical characteristic current and magnetic current acquisition module is used to extract the first typical characteristic current and magnetic current of the radar geometric model according to the current and magnetic current distribution corresponding to the excitation of the first antenna unit;

[0100] A current and magnetic current updating module, used for calculating the current and magnetic current distribution corresponding to the excitation of the antenna unit adjacent to the first antenna unit when the antenna unit adjacent to the first antenna unit is excited, based on the first typical characteristic current and magnetic current of the radar geometric model as the initial solution of the solver;

[0101] An iteration module is used to excite all antenna units and obtain the current and magnetic current distribution corresponding to the excitation of all antenna units;

[0102] The result output module is used to extract the S parameters or unit radiation pattern of the antenna array of the radar geometric model according to the current and magnetic current distribution corresponding to the excitation of all antenna units.

[0103] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the term "include", "comprise" or any other variant is intended to cover non-exclusive inclusion, so that the article or device including a series of elements includes not only those elements, but also other elements that are not explicitly listed. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the article or device including the elements. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The orientation or position relationship indicated by "up", "down", "left", "right", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0104] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0105] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A method for extracting electromagnetic coupling parameters based on multi-layer fast multipole, characterized in that: include: Constructing an electromagnetic model of a radar geometric model; the radar geometric model includes an array antenna and a carrier platform geometric model and a wave port excitation model, the array antenna includes a plurality of antenna units; the electromagnetic model includes an antenna array and a carrier platform electromagnetic model, and a wave port excitation electromagnetic model; wherein, The antenna array and carrier platform electromagnetic model construction process includes: The electric field integral equation and the PMCHW integral equation are used to discretize the geometric model of the array antenna and the carrier platform and establish an electromagnetic model to obtain the electromagnetic model of the antenna array and the carrier platform; wherein, for different regions and , the electric field integral equation and the PMCHW integral equation are expressed as: ； in, The interface consists of the area Pointing area The unit normal vector of Indicates area The electric field in Indicates area The electric field in Indicates area The wave impedance, and Indicates area The integral operator of Represents the interface area Discrete equivalent current, Represents the interface area Discrete equivalent magnetic current, Indicates area The wave impedance, and Indicates area The integral operator of Represents the interface area Discrete equivalent current, Represents the interface area Discrete equivalent magnetic current, Indicates area The magnetic field in Indicates area Magnetic field in The wave port excitation electromagnetic model construction process includes: The wave port excitation is discretized in the wave port excitation model using a preset integral equation and electromagnetic modeling is established to obtain the wave port excitation electromagnetic model; wherein the preset integral equation expression is: ； in, represents the unit normal vector on the port surface from the wave port to the waveguide cavity, represents the equivalent current on the wave port, represents the equivalent magnetic current on the wave port, Indicates the first wave in the port excitation A pattern field, represents the normalized eigenvector of the waveguide, represents the wave impedance in the waveguide, Indicates the port surface; According to the electromagnetic model, a basis function index table of the radar geometric model is obtained; the basis function of the radar geometric model includes basis function information of the antenna unit and basis function information of the carrier platform; According to the basis function index table, using a preset algorithm to calculate the current and magnetic current distribution corresponding to the excitation of the first antenna unit when the first antenna unit is excited; Extracting first typical characteristic current and magnetic current of the radar geometric model according to the current and magnetic current distribution corresponding to the excitation of the first antenna unit; According to the first typical characteristic current and magnetic current of the radar geometric model, as the initial solution of the solver, when the antenna unit adjacent to the first antenna unit is excited, the current and magnetic current distribution corresponding to the excitation of the antenna unit adjacent to the first antenna unit is calculated; Until all antenna units are excited, the current and magnetic current distribution corresponding to the excitation of all antenna units are obtained; According to the current and magnetic current distribution corresponding to the excitation of all the antenna units, the S parameters or unit radiation patterns of the antenna array of the radar geometric model are extracted.

2. The electromagnetic coupling parameter extraction method based on multi-layer fast multipole according to claim 1 is characterized in that: Current and magnetic flow distribution of the radar geometry model The expression is: ； in, represents the equivalent current and magnetic flow corresponding to the carrier platform basis function, Indicates The equivalent current and magnetic current corresponding to the antenna unit basis function are: It represents the equivalent current and magnetic flux corresponding to the excitation of the antenna unit wave port, represents the index of the antenna element, Indicates the total number of antenna elements.

3. The electromagnetic coupling parameter extraction method based on multi-layer fast multipole according to claim 1 is characterized in that: The extracting the first typical characteristic current and magnetic current of the radar geometric model according to the current and magnetic current distribution corresponding to the excitation of the first antenna unit comprises: Obtaining S parameters of a radar geometric model according to the current and magnetic current distribution corresponding to the excitation of the first antenna unit; According to the S parameters of the radar geometric model, first typical characteristic current and magnetic current of the radar geometric model are extracted.

4. The electromagnetic coupling parameter extraction method based on multi-layer fast multipole according to claim 1 is characterized in that: The first typical characteristic current and magnetic flux of the radar geometric model The expression is: ； in, represents the threshold for extracting typical characteristic current and magnetic current, Indicates the number of the selected antenna unit, Indicates the antenna unit currently being solved and the The S parameters of each antenna unit are coupling parameters. Represents the equivalent current and magnetic current corresponding to the carrier platform basis function.

5. The electromagnetic coupling parameter extraction method based on multi-layer fast multipole according to claim 1 is characterized in that: The step of exciting all antenna units and obtaining current and magnetic current distribution corresponding to the excitation of all antenna units includes: The antenna units other than the first antenna unit all use the first typical characteristic current and magnetic current as the initial solution of the solver, and when the antenna units other than the first antenna unit are excited, the current and magnetic current distribution corresponding to the excitation of all the antenna units are calculated; or, The second antenna unit adjacent to the first antenna unit uses the first typical characteristic current and magnetic current as the initial solution of the solver to calculate the current and magnetic current distribution corresponding to the excitation of the second antenna unit when the second antenna unit is excited; according to the current and magnetic current distribution corresponding to the excitation of the second antenna unit, the second typical characteristic current and magnetic current of the radar geometric model are extracted; the third antenna unit adjacent to the second antenna unit uses the second typical characteristic current and magnetic current as the initial solution of the solver to calculate the current and magnetic current distribution corresponding to the excitation of the third antenna unit when the third antenna unit is excited; until all antenna units are excited, the current and magnetic current distribution corresponding to the excitation of all antenna units are obtained.

6. The electromagnetic coupling parameter extraction method based on multi-layer fast multipole according to claim 1 is characterized in that: The expression of the initial solution of the solver is: ； in, Represents the first typical characteristic current and magnetic current, Represents the equivalent current and magnetic current corresponding to the carrier platform basis function.

7. An electromagnetic coupling parameter extraction device based on multi-layer fast multipole, characterized in that: include: The electromagnetic model building module is used to build an electromagnetic model of a radar geometric model; the radar geometric model includes an array antenna and a carrier platform geometric model and a wave port excitation model, and the array antenna includes a plurality of antenna units; the electromagnetic model includes an antenna array and a carrier platform electromagnetic model, and a wave port excitation electromagnetic model; wherein, The antenna array and carrier platform electromagnetic model construction process includes: The electric field integral equation and the PMCHW integral equation are used to discretize the geometric model of the array antenna and the carrier platform and establish an electromagnetic model to obtain the electromagnetic model of the antenna array and the carrier platform; wherein, for different regions and , the electric field integral equation and the PMCHW integral equation are expressed as: ； in, The interface consists of the area Pointing area The unit normal vector of Indicates area The electric field in Indicates area The electric field in Indicates area The wave impedance, and Indicates area The integral operator of Represents the interface area Discrete equivalent current, Represents the interface area Discrete equivalent magnetic current, Indicates area The wave impedance, and Indicates area The integral operator of Represents the interface area Discrete equivalent current, Represents the interface area Discrete equivalent magnetic current, Indicates area The magnetic field in Indicates area Magnetic field in The wave port excitation electromagnetic model construction process includes: The wave port excitation is discretized in the wave port excitation model using a preset integral equation and electromagnetic modeling is established to obtain the wave port excitation electromagnetic model; wherein the preset integral equation expression is: ； in, represents the unit normal vector on the port surface from the wave port to the waveguide cavity, represents the equivalent current on the wave port, represents the equivalent magnetic current on the wave port, Indicates the first wave in the port excitation A pattern field, represents the normalized eigenvector of the waveguide, represents the wave impedance in the waveguide, Indicates the port surface; A basis function index table acquisition module is used to acquire a basis function index table of the radar geometric model according to the electromagnetic model; the basis function of the radar geometric model includes basis function information of the antenna unit and basis function information of the carrier platform; A current and magnetic current distribution acquisition module, used to calculate the current and magnetic current distribution corresponding to the excitation of the first antenna unit when the first antenna unit is excited using a preset algorithm according to the basis function index table; A typical characteristic current and magnetic current acquisition module, used for extracting the first typical characteristic current and magnetic current of the radar geometric model according to the current and magnetic current distribution corresponding to the excitation of the first antenna unit; A current and magnetic current updating module, used for calculating the current and magnetic current distribution corresponding to the excitation of the antenna unit adjacent to the first antenna unit when the antenna unit adjacent to the first antenna unit is excited, based on the first typical characteristic current and magnetic current of the radar geometric model as the initial solution of the solver; An iteration module is used to obtain the current and magnetic current distribution corresponding to the excitation of all antenna units until all antenna units are excited; The result output module is used to extract the S parameters or unit radiation pattern of the antenna array of the radar geometric model according to the current and magnetic current distribution corresponding to the excitation of all the antenna units.

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