A high-power microwave near-field radiation field intensity distribution test method and system

Abstract

The application discloses a kind of high-power microwave near-field radiation field intensity distribution test methods, comprising: constructing the field point grid for representing high-power microwave near-field, by obtaining field intensity gradient step and gradient coefficient, the field intensity discrete data of field point grid is calculated, and after difference estimation, the radiation field intensity distribution of the high-power microwave near-field is represented;The field intensity of grid uniform point distribution method test is used as initial field point data, the radiation field intensity gradient distribution is calculated, and then the gradient coefficient of each grid is calculated, and the grid encryption of three levels is carried out to different grids, according to the grid arrangement field intensity test point after encryption, the field intensity discrete data of each field point is obtained.Kriging space interpolation algorithm is used to carry out interpolation estimation calculation to the field intensity discrete data obtained by grid gradient encryption point distribution test, linear unbiased optimal estimation is carried out to known field intensity data sample in limited domain, and finally the continuous high-power microwave near-field radiation field intensity distribution diagram is obtained.

Description

Technical Field

[0001] This invention relates to a method and system for testing the near-field radiation intensity distribution of high-power microwaves, belonging to the field of electromagnetic environment testing, and particularly to a method and system for testing the near-field electromagnetic environment of high-power microwaves based on gradient-density point layout. Background Technology

[0002] Based on the radiation characteristics of high-power microwave radiating antennas, in the near-field region, the radiating antenna pattern has not yet been formed, and the radiated power exhibits oscillating characteristics with distance. Therefore, the accuracy of testing the near-field radiation field strength distribution based on the far-field radiation pattern is poor.

[0003] Due to the instability of high-power sources, the actual transmitted power will vary each time, making it impossible to obtain the radiation field strength distribution through multiple transmissions of a high-power source. Therefore, to obtain a relatively accurate field strength distribution, test points need to be arranged according to requirements in the near-field region of the high-power microwave transmitting antenna, and multi-point synchronous testing should be performed on a single transmission.

[0004] If a uniform sampling method is used to test the near-field radiation intensity distribution of high-power microwaves, a large number of field strength testing devices need to be deployed simultaneously. Furthermore, using a uniform sampling method in areas with significant field strength variations will result in poor testing accuracy. To ensure the accuracy and reliability of the high-power microwave near-field intensity distribution test, the number of testing points should be minimized to reduce the disturbance of the radiation field by the testing devices, while simultaneously ensuring testing accuracy. Summary of the Invention

[0005] To address the existing technical problems, this invention provides a method and system for testing the near-field radiation intensity distribution of high-power microwaves;

[0006] A method for testing the near-field radiation intensity distribution of high-power microwaves includes: constructing a field point grid to characterize the near-field of high-power microwaves; obtaining the field intensity gradient steps and gradient coefficients; calculating the discrete field intensity data of the field point grid; and performing difference estimation to characterize the radiation intensity distribution of the near-field of the high-power microwaves.

[0007] Preferably, the environmental field strength is tested using a uniform grid distribution method as the initial field point data, and the gradient of the field strength E is calculated based on the initial field point data:

[0008]

[0009] E is the electric field strength, and the coordinates x and y are the independent and dependent variables of the electric field strength E function. i and j are the unit vectors in the x and y directions, respectively.

[0010] Preferably, the magnitude of the gradient is:

[0011]

[0012] The uniform grid sampling method samples from a grid of density n×m, with a grid spacing of Δx in the x-direction and Δy in the y-direction. At point (i,j), the measured value of the electric field strength E is Ei. i,j Its partial derivative is:

[0013]

[0014]

[0015] The field intensity gradient magnitude at each grid point is calculated using equations (2), (3), and (4). The maximum gradient magnitude max|grad(E)| and the average gradient magnitude are then calculated from the field intensity gradient magnitude. This then generates the gradient coefficient α.

[0016] Preferably, in the process of obtaining the average gradient magnitude through the field strength gradient magnitude, the average gradient magnitude is expressed as:

[0017]

[0018] Preferably, in the process of generating gradient coefficients, the generated gradient coefficients are represented as follows:

[0019]

[0020] Preferably, the value of α0 is derived from experience, with a typical value of α0 = 0.15, to control the reasonable setting of the number of points so as not to make the grid too dense; when the gradient coefficient α > α0, the gradient in this area is large, and it is necessary to refine the grid or reduce the number of points in the grid with small gradient coefficient.

[0021] Preferably, α max The maximum grid gradient coefficient, α0~α max The grid between the points is divided into three equal parts, and the gradient coefficients are arranged in ascending order to obtain discrete field strength data for each field point by densifying the grid at different levels.

[0022] Preferably, the Kriging spatial interpolation algorithm is used to perform interpolation estimation on the discrete field strength data, and linear unbiased optimal estimation is performed on the field strength data samples to obtain a radiation field strength distribution map of the continuous high-power microwave near field to characterize the radiation field strength distribution.

[0023] A high-power microwave near-field radiation intensity distribution testing system includes:

[0024] The data acquisition module is used to collect field point data for testing the environmental field strength using the uniform grid distribution method.

[0025] The data processing module is used to generate a field grid for characterizing the near field of high-power microwaves based on the field data.

[0026] The characterization module is used to calculate the discrete field strength data of the field point grid by acquiring the field strength gradient step and gradient coefficient according to the field point network, and after performing difference estimation, generate a radiation field strength distribution map to characterize the radiation field strength distribution of the high-power microwave near field.

[0027] The present invention discloses the following technical effects:

[0028] 1. A method for testing the near-field radiation intensity distribution of high-power microwaves using a grid gradient densification method. The method uses the field intensity obtained from a uniform grid densification method as initial field point data, calculates the gradient distribution of the radiation field intensity, and then calculates the gradient coefficient of each grid. Three levels of grid densification are applied to different grids. Field intensity test points are arranged according to the densified grid to obtain discrete field intensity data for each point. The Kriging spatial interpolation algorithm is used to interpolate and estimate the discrete field intensity data obtained from the grid gradient densification test. Within a finite domain, a linear unbiased optimal estimation is performed on the known field intensity data samples, ultimately obtaining a continuous high-power microwave near-field radiation intensity distribution map.

[0029] 2. A high-power microwave near-field radiation field strength distribution testing system, the testing device consists of a horn antenna, a high-power attenuator, a detector, an RF cable, and an oscilloscope. The horn antenna with low gain and high power capacity is used to receive high-power radiated signals. Since high-power microwave electromagnetic pulses have high peak values, a high-power attenuator is added at the front end of the testing system to attenuate the signal to a certain extent. The signal is then converted into a pulse voltage by the detector and transmitted to the oscilloscope. Finally, the field strength at the test point is calculated by back-calculating the attenuation of the test system path. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 A flowchart illustrating a method for testing the near-field radiation intensity distribution of high-power microwaves, provided as an example of the present invention.

[0032] Figure 2 A schematic diagram of a high-power microwave near-field radiation intensity distribution testing device provided as an example of the present invention;

[0033] Figure 3 An initial field strength test layout diagram based on the grid uniform point distribution method is provided as an example of the present invention.

[0034] Figure 4 A schematic diagram of a gradient grid densification point layout method provided as an example of the present invention;

[0035] Figure 5 This is an example diagram of a field layout after being encrypted using a gradient grid, provided as an example of the present invention. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0037] Figure 1 This invention discloses a method for testing the near-field radiation intensity distribution of high-power microwaves. The method involves acquiring the field intensity gradient steps and gradient coefficients, calculating the discrete field intensity data of the field point grid, performing linear unbiased optimal estimation on the field intensity data samples, and obtaining a continuous radiation intensity distribution map of the high-power microwave near-field to characterize the radiation intensity distribution. The method includes: constructing a field point grid to characterize the high-power microwave near-field; acquiring the field intensity gradient steps and gradient coefficients; calculating the discrete field intensity data of the field point grid; performing difference estimation; and characterizing the radiation intensity distribution of the high-power microwave near-field.

[0038] Preferably, the environmental field strength is tested using a uniform grid distribution method as the initial field point data, and the gradient of the field strength E is calculated based on the initial field point data:

[0039]

[0040] E is the electric field strength, and the coordinates x and y are the independent and dependent variables of the electric field strength E function. i and j are the unit vectors in the x and y directions, respectively.

[0041] Preferably, the magnitude of the gradient is:

[0042]

[0043] The uniform grid sampling method samples from a grid of density n×m, with a grid spacing of Δx in the x-direction and Δy in the y-direction. At point (i,j), the measured value of the electric field strength E is Ei. i,j Its partial derivative is:

[0044]

[0045]

[0046] The field intensity gradient magnitude at each grid point is calculated using equations (2), (3), and (4). The maximum gradient magnitude max|grad(E)| and the average gradient magnitude are then calculated from the field intensity gradient magnitude. This then generates the gradient coefficient α.

[0047] Preferably, in the process of obtaining the average gradient magnitude through the field strength gradient magnitude, the average gradient magnitude is expressed as:

[0048]

[0049] Preferably, in the process of generating gradient coefficients, the generated gradient coefficients are represented as follows:

[0050]

[0051] Preferably, the value of α0 is derived from experience, with a typical value of α0 = 0.15, to control the reasonable setting of the number of points so as not to make the grid too dense; when the gradient coefficient α > α0, the gradient in this area is large, and it is necessary to refine the grid or reduce the number of points in the grid with small gradient coefficient.

[0052] Preferably, α max The maximum grid gradient coefficient, α0~α max The grid between the points is divided into three equal parts, and the gradient coefficients are arranged in ascending order to obtain discrete field strength data for each field point by densifying the grid at different levels.

[0053] Preferably, the Kriging spatial interpolation algorithm is used to perform interpolation estimation on the discrete field strength data, and linear unbiased optimal estimation is performed on the field strength data samples to obtain a radiation field strength distribution map of the continuous high-power microwave near field to characterize the radiation field strength distribution.

[0054] This invention also discloses a high-power microwave near-field radiation field strength distribution testing system, which is used to realize the function of testing the high-power microwave near-field radiation field strength distribution. By acquiring the field strength gradient step and gradient coefficient, the system calculates the field strength discrete data of the field point grid, performs linear unbiased optimal estimation on the field strength data sample, and obtains a continuous high-power microwave near-field radiation field strength distribution map to characterize the radiation field strength distribution.

[0055] Includes: a data acquisition module, used to obtain field point data for testing environmental field strength using a grid uniform point distribution method;

[0056] The data processing module is used to generate a field grid for characterizing the near field of high-power microwaves based on the field data.

[0057] The characterization module is used to calculate the discrete field strength data of the field point grid by acquiring the field strength gradient step and gradient coefficient according to the field point network, and after performing difference estimation, generate a radiation field strength distribution map to characterize the radiation field strength distribution of the high-power microwave near field.

[0058] Figure 1A flowchart of a method for testing the near-field radiation intensity distribution of high-power microwaves is provided, comprising the following steps: Step S1, using a uniform grid distribution method and a high-power microwave near-field radiation intensity distribution testing device to test the environmental field intensity as initial field point data. Step S2, calculating the field intensity gradient distribution based on the initial field point data, and then calculating the gradient coefficient of each grid, performing three levels of grid refinement on different grids. Step S3, arranging field intensity test points according to the refined grid, and obtaining discrete field intensity data for each field point. Step S4, using the Kriging spatial interpolation algorithm to interpolate and estimate the discrete field intensity data, finally obtaining a continuous high-power microwave near-field radiation intensity distribution map.

[0059] Figure 2 A schematic diagram of a high-power microwave near-field radiation intensity distribution testing device is provided. This device, used to achieve the aforementioned system functions, includes a horn antenna, a high-power attenuator, a detector, an RF cable, and an oscilloscope. The basic principle of the testing device is as follows: a low-gain, high-power horn antenna is used to receive high-power radiated signals. Due to the high peak value of high-power microwave electromagnetic pulses, a high-power attenuator is added at the front end of the testing system to attenuate the signal to a certain extent. The signal is then converted into a pulse voltage by the detector, transmitted to the oscilloscope, and finally, the field strength at the test point is calculated by back-calculating the attenuation of the testing system path.

[0060] Figure 3 An initial field strength testing layout based on a grid uniform point distribution method is provided. The grid uniform point distribution method is employed, and a high-power microwave near-field radiation field strength distribution testing device is used to measure the field strength at each point as initial data.

[0061] Figure 4 A gradient grid densification method is provided. The field strength gradient distribution is calculated based on initial field point data, and then the gradient coefficients of each grid are calculated. Let the field strength E be a function of planar coordinates x and y, denoted as E(x,y). The gradient of E is defined as:

[0062]

[0063] In the formula: i, j represent unit vectors in the x and y directions, and the magnitude of the gradient is:

[0064]

[0065] Assuming the uniform grid sampling method divides the sample into a grid of density n×m, with a grid spacing of Δx in the x-direction and Δy in the y-direction, the measured value of the electric field strength E at point (i,j) is E. i,j Its partial derivatives can be approximated as:

[0066]

[0067]

[0068] Substituting equations (3) and (4) into equation (2) yields the magnitude of the field intensity gradient at each grid point, and then the gradient coefficients of each grid can be calculated. The formula for calculating the grid gradient coefficients is as follows:

[0069]

[0070]

[0071] Where: grad(E) i，j ) represents the gradient of Ei,j; grad(E i+Δx，j Let grad(Ei,j) be the gradient of Ei,j with a grid distance of Δx in the x-direction and a constant grid distance in the y-direction; i，j+Δy ) represents the gradient of Ei,j with constant grid spacing in the x-direction and grid spacing of Δy in the y-direction; grad(E i+Δx,j+Δy Let α be the gradient of Ei,j with grid spacing Δx in the x-direction and Δy in the y-direction. In the formula, α is the gradient coefficient; E is the field strength parameter value. The average gradient value within each rectangular grid; max|grad(E)| is the maximum gradient value within the entire grid.

[0072] When the gradient coefficient α > α0, it indicates a large gradient in the region, requiring mesh refinement. Otherwise, no refinement is needed, or the number of points should be reduced in areas with low gradient coefficients. The value of α0 is derived empirically, with a typical value of α0 = 0.15. This value helps control the number of points to avoid over-refinement. Different levels of mesh refinement are applied based on the principle that more points are placed in complex regions with larger gradient coefficients. Assume α... max To determine the maximum grid gradient coefficient, then α0~α max The grid is divided into three equal parts, and the gradient coefficients are increased to densify the grid at different levels.

[0073] Figure 5 An example diagram of the field point layout after gradient grid refinement is provided. The field strength testing device is arranged according to the refined field point layout diagram to obtain discrete field strength data for each field point. The Kriging spatial interpolation algorithm is used to perform interpolation estimation calculations on the discrete field strength data. Within a finite domain, linear unbiased optimal estimation is performed on the known field strength data samples, ultimately obtaining a continuous high-power microwave near-field radiation field strength distribution map.

[0074] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0075] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

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

Claims

1. A method for testing the near-field radiation intensity distribution of high-power microwaves, characterized in that... include: A field point grid for characterizing the near field of high-power microwaves is constructed. The field strength measured by the uniform grid distribution method is used as the initial field point data. The gradient distribution of the radiation field strength is calculated, and then the gradient coefficient of each grid is calculated. Three levels of grid refinement are applied to different grids. Field strength test points are arranged according to the refined grid. The discrete field strength data of each field point in the field point grid is calculated. The Kriging spatial interpolation algorithm is used to interpolate and estimate the discrete field strength data obtained by the grid gradient refinement test. In a finite domain, linear unbiased optimal estimation is performed on the known field strength data samples to obtain a radiation field strength distribution map for characterizing the radiation field strength distribution of the continuous high-power microwave near field.

2. The method for testing the near-field radiation intensity distribution of high-power microwaves according to claim 1, characterized in that: The environmental field strength was measured using a uniform grid distribution method as the initial field point data. The gradient of the field strength E was then calculated based on the initial field point data. E is the electric field strength, and the coordinates x and y are the independent and dependent variables of the electric field strength E function. i and j are the unit vectors in the x and y directions, respectively.

3. The method for testing the near-field radiation intensity distribution of high-power microwaves according to claim 2, characterized in that: The magnitude of the gradient is: The uniform grid sampling method samples from a grid of density n×m, with a grid spacing of Δx in the x-direction and Δy in the y-direction. At point (i,j), the measured value of the electric field strength E is Ei. i,j Its partial derivative is: The field intensity gradient magnitude at each grid point is calculated using equations (2), (3), and (4). The maximum gradient magnitude max|grad(E)| and the average gradient magnitude are then calculated from the field intensity gradient magnitude. This then generates the gradient coefficient α.

4. The method for testing the near-field radiation intensity distribution of high-power microwaves according to claim 3, characterized in that: In the process of obtaining the average gradient magnitude through the field strength gradient magnitude, the average gradient magnitude is expressed as:

5. The method for testing the near-field radiation intensity distribution of high-power microwaves according to claim 4, characterized in that: In the process of generating gradient coefficients, the generated gradient coefficients are represented as follows:

6. The method for testing the near-field radiation intensity distribution of high-power microwaves according to claim 5, characterized in that: The value of α0 is derived from experience, with a typical value of α0 = 0.

15. This helps to control the number of points to be set reasonably so as not to make the grid too dense. When the gradient coefficient α > α0, the gradient in this area is large, and the grid needs to be denser or the number of points should be reduced in the areas with small gradient coefficients.

7. The method for testing the near-field radiation intensity distribution of high-power microwaves according to claim 6, characterized in that: α max The maximum grid gradient coefficient, α0~α max The grid between the points is divided into three equal parts, and the gradient coefficients are arranged in ascending order to obtain discrete field strength data for each field point by densifying the grid at different levels.

8. A high-power microwave near-field radiation intensity distribution testing system, characterized in that... include: The data acquisition module is used to collect field point data for testing the environmental field strength using the uniform grid distribution method. The data processing module is used to generate a field grid for characterizing the near field of high-power microwaves based on the field data. The characterization module uses the field strength obtained from the uniform grid-based test as initial field point data to calculate the radiation field strength gradient distribution, and then calculates the gradient coefficient of each grid. It performs three levels of grid refinement on different grids, arranges field strength test points according to the refined grid, calculates the discrete field strength data of each field point in the grid, and uses the Kriging spatial interpolation algorithm to interpolate and estimate the discrete field strength data obtained from the grid gradient refinement test. In a finite domain, it performs linear unbiased optimal estimation on the known field strength data samples to obtain a continuous high-power microwave near-field radiation field strength distribution map for characterizing the radiation field strength distribution.

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