A method for compensating electrical performance of high-temperature ablative radome based on array element phase adjustment

Abstract

The present invention discloses a method for compensating the electrical performance of a high-temperature ablation radome based on array element phase adjustment. Based on data on the temperature distribution of the radome in an operating environment and changes in its material properties with temperature, the portion of the radome whose temperature exceeds the ablation temperature is reconstructed as an air radome when establishing a finite element model of the radome. Full-wave calculations using COMLOL are used to determine the electrical performance of the array antenna after loading the high-temperature ablation radome. The optimal phase distribution of the array antenna within the radome is iteratively solved using a particle swarm optimization algorithm, thereby compensating for the effects of high-temperature ablation on the radome's electrical performance. This method, while ensuring compensation accuracy, takes into account the effects of high-temperature ablation on the radome's electrical performance. The method boasts high compensation effectiveness and accuracy, and is widely applicable.

Description

Technical Field

[0001] The present invention belongs to the technical field of radar antennas, and in particular relates to a method for compensating the electrical performance of a high-temperature ablation radome based on array element phase adjustment. Background Art

[0002] Aircraft radomes primarily protect the electronic equipment within, preventing damage from rain, snow, wind loads, lightning strikes, and other flight conditions. To meet aerodynamic requirements, aircraft radomes are typically designed to be streamlined. This structure significantly impacts the electrical performance of the electronics within the radome, but through superior structural design, these performance requirements can be met.

[0003] During the service life of an aircraft, severe aerodynamic heating occurs, causing the temperature of the radome at the front of the aircraft to rise dramatically. When the temperature exceeds a certain limit, the radome will ablate, causing changes in the radome's material parameters and structure, which may have positive or negative impacts on electrical performance. Because it is difficult to compensate for changes in electrical performance by adjusting the radome's structure during service, the method of adjusting the excitation phase of the antenna inside the radome is generally used to compensate for electrical performance. This requires the preparation of pre-adjustment plans for the antenna phase distribution under various flight conditions during the radome's early design phase, thereby improving the electrical performance of the aircraft radome during service.

[0004] Currently, research results on the impact of high-temperature ablation of antenna covers on electrical performance vary. CN111539141A discloses a method for rapidly compensating the electrical performance of active phased array antennas under high-temperature ablation. This method, based on geometric optics, treats the electromagnetic wave as a ray emanating from the antenna's radiation source. The equivalent transmission line theory then calculates the changes in amplitude and phase after the electromagnetic wave passes through the high-temperature ablated antenna cover. The antenna phase is then compensated based on these changes. While this geometric optics compensation method, based on high-frequency approximation, offers rapid calculation speed, it struggles to guarantee accuracy. Wang Wei's 2015 paper, "Rapid Optimization of Antenna Cover Aiming Error Based on Array Element Phase Control," discloses a method for rapidly optimizing the aiming error of a covered antenna by adjusting the excitation phase of a phased array unit. Based on a particle swarm algorithm, both continuously variable phase and digital discrete phase adjustment optimization are achieved. However, when the antenna cover is heated to high temperatures, the dielectric constant and loss tangent of the material change with temperature, making its electrical performance difficult to guarantee. Summary of the Invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a method for compensating the electrical performance of a high-temperature ablation radome based on array element phase adjustment. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0006] The present invention provides a method for compensating the electrical performance of a high-temperature ablation radome based on array element phase adjustment, the method comprising:

[0007] S1: Determine the structural parameters and material properties of the aircraft's radome;

[0008] S2: determining the flight condition of the aircraft's radome according to the aircraft's flight curve;

[0009] S3: Using the commercial software Fluent, a flow field and a fluid calculation grid model of the aircraft's radome are established based on the structural parameters and flight conditions, thereby obtaining temperature distribution data on the outer surface of the radome;

[0010] S4: The temperature distribution data and material property data of the radome outer surface are imported into the commercial software COMLOL in the form of interpolation functions to construct a finite element model of the high-temperature ablation radome;

[0011] S5: Using MATLAB, based on particle swarm optimization parameters, randomly generate the phase distribution of the antenna array inside the radome and specify the scanning angle of the antenna array; the particle swarm optimization parameters include: the number of individuals in the optimization population and the maximum number of iterations;

[0012] S6: using commercial software COMLOL, obtaining a first far-field pattern of the array antenna based on the phase distribution and the scanning angle, and extracting electrical performance of the array antenna from the first far-field pattern;

[0013] S7: Using the commercial software COMLOL, based on the finite element model, phase distribution, and scanning angle of the high-temperature ablative radome, a second far-field pattern of the array antenna after the high-temperature ablative radome is installed is obtained, thereby determining the electrical performance of the array antenna after the high-temperature ablative radome is installed;

[0014] S8: establishing an optimization design model based on the phase distribution of the antenna array and the electrical performance of the array antenna after being loaded with a high-temperature ablation radome; and iterating the optimization design model for a maximum number of times using a particle swarm optimization algorithm in MATLAB to obtain an optimized phase distribution of the array antenna.

[0015] S9: Based on the electrical performance requirements of the antenna design, determine whether the change in the electrical performance of the optimized antenna meets the preset requirements. If so, output the optimized array antenna phase distribution; otherwise, adjust the particle swarm optimization parameters and repeat steps S5 to S9 until the preset requirements are met.

[0016] In one embodiment of the present invention, the structural parameters of the radome include:

[0017] The height, diameter, thickness of the radome and the distribution position of the array antenna inside the radome.

[0018] In one embodiment of the present invention, the material properties of the radome include:

[0019] Thermal conductivity Q, specific heat capacity C P , dielectric constant epu and loss tangent loss curves changing with temperature.

[0020] In one embodiment of the present invention, the flight operating conditions of the radome include:

[0021] The flight altitude, flight speed and angle of attack of the radome.

[0022] In one embodiment of the present invention, the temperature distribution data and material property changes of the outer surface of the radome are imported into the commercial software COMLOL in the form of an interpolation function to construct a finite element model of the high-temperature ablation radome, including:

[0023] The temperature distribution data was processed into a first data table with J rows and 3 columns using the commercial software Fluent. The format of the first data table is as follows:

[0024] (x j ,y j ,T j ), j = 1, 2, ..., J;

[0025] Where j represents the jth grid node in the fluid calculation grid model of the radome, J represents the total number of grid nodes in the fluid calculation grid model, and x j ,y j represents the coordinates of the grid nodes, T j Indicates the temperature corresponding to the j-th grid node;

[0026] Data on changes in material properties with temperature are extracted from the material properties of the radome, and the data on changes in material properties with temperature are processed into a second data table with K rows and 2 columns; the format of the second data table is as follows:

[0027] (T k ,value k ),k=1,2,…,K;

[0028] Where k represents the kth sampling point in the temperature curve of the radome material, K represents the total number of sampling points, and T k Indicates the temperature of the sampling point, value k Indicates the material parameter value corresponding to the kth sampling point;

[0029] Import the first and second data tables into the interpolation function interface of the commercial software COMLOL to construct the temperature interpolation function T(x,y), thermal conductivity interpolation function Q(T), and specific heat capacity interpolation function C P (T), dielectric constant interpolation function epu(T) and loss tangent interpolation function loss(T), simulate the state of radome ablation;

[0030] In the radome material parameter setting in the commercial software COMLOL, the thermal conductivity is set to Q(T) and the specific heat capacity is set to C P (T), the dielectric constant is set to epu(T), the loss tangent is set to loss(T), and the temperature boundary condition is set to T(x,y) in the boundary condition setting to obtain the finite element model of the high-temperature ablation antenna cover.

[0031] In one embodiment of the present invention, using MATLAB, based on particle swarm optimization parameters, randomly generating the phase distribution of the antenna array in the radome and specifying the scanning angle of the antenna array, includes:

[0032] The rand function in MATLAB is used to randomly generate the phase distribution of each array unit in the antenna array inside the radome. The number of array units is equal to the number of individuals in the optimization population in the particle swarm optimization parameters. The phase distribution of the array unit ranges from [-180° to 180°], and the scanning angle of the array unit is obtained by default.

[0033] In one embodiment of the present invention, the electrical performance of the array antenna includes:

[0034] Main beam peak G0, main beam position B0, left first sidelobe level LSSL0, right first sidelobe level RSLL0 and main beam half power beamwidth HPPBW0.

[0035] In one embodiment of the present invention, the commercial software COMLOL is used to obtain a second far-field pattern of the array antenna after the high-temperature ablative radome is installed based on the finite element model, phase distribution, and scanning angle of the high-temperature ablative radome, thereby determining the electrical performance of the array antenna after the high-temperature ablative radome is installed, including:

[0036] Using the commercial software COMLOL and the finite element model of the high-temperature ablative radome, the phase distribution and scanning angle of the array element corresponding to each individual in the optimized population were simulated to obtain the second far-field pattern of the array antenna equipped with the high-temperature ablative radome.

[0037] Using the COMSOL Multiphysics with MATLAB interface of the commercial software COMSOL and MATLAB co-simulation, the main beam peak G1 after loading the high-temperature ablation radome, the main beam position B1 after loading, the left first sidelobe level LSSL1 after loading, the right first sidelobe level RSLL1 after loading, and the main beam half-power beamwidth HPPBW1 after loading were extracted from the second far-field pattern;

[0038] Based on the main beam peak G0, main beam position B0, left first sidelobe level LSSL0, right first sidelobe level RSLL0, main beam half-power beam width HPPBW0, loaded main beam peak G1, loaded main beam position B1, loaded left first sidelobe level LSSL1, loaded right first sidelobe level RSLL1 and loaded main beam half-power beam width HPPBW1, the electrical performance of the array antenna after loading the high-temperature ablation antenna cover is obtained; wherein, the electrical performance of the array antenna after loading the high-temperature ablation antenna cover includes: aiming error BSE, maximum gain loss TLM, left first sidelobe level loss TLL, right first sidelobe level loss TLR and main beam half-power beam width loss TLB.

[0039] In one embodiment of the present invention, the optimization design model is as follows:

[0040]

[0041] Among them, φ n represents the phase distribution of the nth array element in the antenna array, BSE1 represents the pointing error caused by the radome under the specified flight condition, TLM1 represents the maximum gain loss caused by the radome under the specified flight condition, TLL1 represents the level loss of the left first sidelobe caused by the radome under the specified flight condition, TLR1 represents the level loss of the right first sidelobe caused by the radome under the specified flight condition, TLB1 represents the main beam half-power beamwidth loss caused by the radome under the specified flight condition, BSE0, TLM0, TLL0, TLR0 and TLB0 represent the normalization coefficients corresponding to the electrical performance of the array antenna under the specified flight condition.

[0042] In one embodiment of the present invention, the particle swarm optimization algorithm is used in MATLAB to perform an iterative process of the maximum number of iterations on the optimization design model, including:

[0043] The phase distributions of all array elements in the antenna array are regarded as a particle swarm, and each phase distribution is regarded as a particle; for each particle in the particle swarm, the fitness value of the particle is obtained using the optimization design model;

[0044] The best fitness value among all particles is selected as the optimal individual fitness value. If the optimal individual fitness value is better than the optimal individual fitness value obtained in the previous iterative processing process, the individual optimal position and global optimal position of the particle swarm are updated according to the update formula, and the updated individual optimal position and global optimal position of the particle swarm are used for the next iterative processing process.

[0045] Beneficial effects of the present invention:

[0046] The proposed solution, based on data on the temperature distribution of the radome in its operating environment and the temperature-dependent changes in its material properties, reconstructs the portion of the radome where the temperature exceeds the ablation temperature into an air radome when constructing a finite element model of the high-temperature ablation radome. Using COMLOL, full-wave calculations are performed to determine the electrical performance of the array antenna after installing the high-temperature ablation radome. A particle swarm optimization algorithm is then used to iteratively determine the optimal phase distribution of the array antenna within the radome, thereby compensating for the effects of high-temperature ablation on the radome's electrical performance. This approach not only ensures compensation accuracy but also accounts for the effects of high-temperature ablation on the radome's electrical performance, resulting in high compensation effectiveness and accuracy, as well as broad applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A schematic diagram of the steps of a method for compensating the electrical performance of a high-temperature ablation radome based on array element phase adjustment provided by an embodiment of the present invention;

[0048] Figure 2 A schematic flow chart of a method for compensating electrical performance of a high-temperature ablation radome based on array element phase adjustment provided by an embodiment of the present invention;

[0049] Figure 3 A schematic structural diagram of an aircraft radome provided by an embodiment of the present invention;

[0050] Figure 4 A schematic diagram of a finite element model of a high-temperature ablative radome provided by an embodiment of the present invention;

[0051] Figure 5 A temperature distribution cloud diagram of the outer surface of a radome provided in an embodiment of the present invention;

[0052] Figure 6a-6d A schematic diagram of a curve showing data of material properties changing with temperature provided by an embodiment of the present invention;

[0053] Figure 7 A phase distribution diagram of a compensated array antenna provided by an embodiment of the present invention;

[0054] Figure 8 A directional pattern of a compensated front and rear array antenna provided by an embodiment of the present invention.

[0055] Reference numerals:

[0056] 1-radome outer surface boundary, 2-fluid calculation inflow boundary, 3-fluid calculation outlet boundary. DETAILED DESCRIPTION

[0057] The present invention will be further described in detail below with reference to specific examples, but the embodiments of the present invention are not limited thereto.

[0058] See the schematic diagram of the steps of the method for compensating the electrical performance of a high-temperature ablation radome based on array element phase adjustment provided in the embodiment of the present invention. Figure 1 , please see the corresponding process diagram Figure 2 , the following will be combined Figure 1 and Figure 2 Each step of the method is introduced separately.

[0059] An embodiment of the present invention provides a method for compensating electrical performance of a high-temperature ablative radome based on array element phase adjustment, which may include:

[0060] S1: Determine the structural parameters and material properties of the aircraft's radome.

[0061] Specifically, the structural parameters of the radome, such as Figure 3 As shown, this may include:

[0062] The height, diameter, thickness of the radome and the distribution position of the array antenna inside the radome.

[0063] The design of the structural parameters of the radome can be based on Figure 3 The design is shown in the relevant parameters, and you can also design it according to specific needs.

[0064] Material properties of the radome, which can include:

[0065] Thermal conductivity Q and specific heat capacity C of the material P , the characteristics of dielectric constant epu and loss tangent loss changing with temperature.

[0066] S2: Determine the flight condition of the aircraft's radome according to the aircraft's flight curve.

[0067] Specifically, the flight conditions of the radome may include:

[0068] The flight altitude, flight speed and angle of attack of the radome.

[0069] S3: Using the commercial software Fluent, a fluid calculation grid model of the flow field and the aircraft's radome is established based on the structural parameters and flight conditions, thereby obtaining the temperature distribution data on the outer surface of the radome.

[0070] Specifically, in the commercial software Fluent, a steady-state thermal analysis of the aircraft's radome is performed based on the structural parameters and flight conditions, and a flow field and a fluid calculation grid model of the aircraft's radome are established, such as Figure 4 As shown in Figure 2, the temperature distribution data of the outer surface of the radome is obtained. Figure 4 It can be seen that the fluid calculation grid model of the radome can include: the radome outer surface boundary 1, the fluid calculation inflow boundary 2, and the fluid calculation outlet boundary 3. For the corresponding radome outer surface temperature distribution cloud diagram, please refer to Figure 5 .

[0071] S4: The temperature distribution data of the outer surface of the radome and the data on the variation of material properties with temperature are imported into the commercial software COMLOL in the form of an interpolation function to construct a finite element model of the high-temperature ablation radome.

[0072] Specifically, for S4, it may include:

[0073] S41, extracting temperature distribution data of the outer surface of the radome from the commercial software Fluent, and processing the temperature distribution data into a first data table with J rows and 3 columns; the format of the first data table is as follows:

[0074] (x j ,y j ,T j ), j = 1, 2, ..., J;

[0075] Where j represents the jth grid node in the fluid calculation grid model of the radome, J represents the total number of grid nodes in the fluid calculation grid model, and x j ,y j represents the coordinates of the grid nodes, T j Indicates the temperature corresponding to the j-th grid node.

[0076] S42, extracting data on the variation of material properties with temperature from the material properties of the radome, and processing the data on the variation of material properties with temperature into a second data table with K rows and 2 columns; the format of the second data table is as follows:

[0077] (T k ,value k ),k=1,2,…,K;

[0078] Where k represents the kth sampling point in the temperature curve of the radome material, K represents the total number of sampling points, and T k Indicates the temperature of the sampling point, value k It represents the material parameter value corresponding to the kth sampling point. It can be understood that the material properties are functions of temperature and will change with temperature. The material parameter value is the value corresponding to the material property at the sampling point.

[0079] For a detailed diagram of the curve of material properties changing with temperature, please refer to Figure 6a-6d ;in, Figure 6a represents the specific heat capacity C of the radome P The temperature-dependent curve, Figure 6b A graph showing the thermal conductivity Q of the radome as a function of temperature, Figure 6c A graph showing how the dielectric constant epu of the radome changes with temperature. Figure 6d A graph showing how the loss tangent of the radome changes with temperature.

[0080] S43, importing the first data table and the second data table into the interpolation function interface of the commercial software COMLOL, constructing the temperature interpolation function T(x,y), the thermal conductivity interpolation function Q(T), and the specific heat capacity interpolation function C P (T), dielectric constant interpolation function epu(T) and loss tangent interpolation function loss(T) are used to simulate the state of radome ablation.

[0081] Specifically, extrapolation interpolation is used for the dielectric constant interpolation function epu(T) and the loss tangent interpolation function loss(T), that is, when the temperature exceeds the ablation temperature, the dielectric constant is extrapolated to 1 and the loss tangent is extrapolated to 0. The part of the antenna cover whose temperature exceeds the ablation temperature is regarded as an air cover to simulate the state of the antenna cover ablation. The selected coordinate system can be the two-dimensional global coordinate system O-xy of COMSOL, and T represents the temperature variable.

[0082] S44, in the radome material parameter setting in the commercial software COMLOL, set the thermal conductivity to Q(T) and the specific heat capacity to C P (T), the dielectric constant is set to epu(T), the loss tangent is set to loss(T), and the temperature boundary condition is set to T(x,y) in the boundary condition setting to obtain the finite element model of the high-temperature ablation antenna cover.

[0083] The method for compensating the electrical properties of a high-temperature ablation radome provided in an embodiment of the present invention reconstructs the portion of the radome where the temperature exceeds the ablation temperature into an air hood based on the temperature distribution of the radome in a working environment and the data on changes in material properties with temperature, thereby obtaining a finite element model of the high-temperature ablation radome.

[0084] S5: Using MATLAB, based on the particle swarm optimization parameters, the phase distribution of the antenna array inside the radome is randomly generated, and the scanning angle of the antenna array is specified; the particle swarm optimization parameters include: the number of individuals in the optimization population and the maximum number of iterations.

[0085] Specifically, for S5, using MATLAB, based on particle swarm optimization parameters, randomly generating the phase distribution of the antenna array in the radome and specifying the scanning angle of the antenna array can include:

[0086] The rand function in MATLAB is used to randomly generate the phase distribution of each array unit in the antenna array inside the radome. The number of array units is equal to the number of individuals in the optimization population in the particle swarm optimization parameters. The phase distribution of the array unit ranges from [-180° to 180°], and the scanning angle of the array unit can be obtained by default.

[0087] It is understandable that the array antenna inside the radome can be represented by a set of electric point dipoles. The dipole moment direction of each electric point dipole is parallel to the x-direction, and the corresponding current is:

[0088]

[0089] Among them, n represents the number of the electric point dipole, A n represents the amplitude of the nth current, e represents the natural constant, j represents the imaginary unit, and N represents the total number of electric point dipoles; φ n represents the phase of the nth current, which corresponds to the phase distribution of the nth array element.

[0090] The number of individuals and the maximum number of iterations in the particle swarm optimization parameters are set, and the rand function in MATLAB is used to randomly generate the population. Each individual in the population corresponds to a phase distribution of the array antenna, thereby obtaining the phase distribution of each array unit in the antenna array inside the radome.

[0091] S6: Using the commercial software COMLOL, based on the phase distribution and the scanning angle, the first far-field pattern of the array antenna is obtained, and the electrical performance of the array antenna is extracted from the first far-field pattern.

[0092] Specifically, for S6, it may include:

[0093] S61, using COMSOL simulation to simulate the phase distribution and scanning angle of the array unit in the array antenna corresponding to each individual in the population, to obtain a first far-field pattern of the array antenna.

[0094] S62, using the COMSOL Multiphysics with MATLAB interface of the commercial software COMSOL and MATLAB co-simulation, extract the electrical performance of the array antenna from the first far-field pattern.

[0095] The electrical performance of the array antenna may include:

[0096] Main beam peak G0, main beam position B0, left first sidelobe level LSSL0, right first sidelobe level RSLL0 and main beam half power beamwidth HPPBW0.

[0097] S7: Using the commercial software COMLOL, based on the finite element model, phase distribution, and scanning angle of the high-temperature ablative radome, the second far-field radiation pattern of the array antenna after the high-temperature ablative radome is installed is obtained, thereby determining the electrical performance of the array antenna after the high-temperature ablative radome is installed.

[0098] Specifically, for S7, it may include:

[0099] S71, using the commercial software COMLOL, based on the finite element model of the high-temperature ablative radome, simulates the phase distribution and scanning angle of the array unit corresponding to each individual in the optimized population, and obtains the second far-field radiation pattern after the array antenna is equipped with the high-temperature ablative radome.

[0100] S72, using the COMSOL Multiphysics with MATLAB interface of the commercial software COMSOL and MATLAB co-simulation, extract the main beam peak G1 after loading the high-temperature ablation radome, the main beam position B1 after loading, the left first sidelobe level LSSL1 after loading, the right first sidelobe level RSLL1 after loading, and the main beam half-power beamwidth HPPBW1 after loading from the second far-field radiation pattern.

[0101] S73, based on the main beam peak G0, the main beam position B0, the left first sidelobe level LSSL0, the right first sidelobe level RSLL0, the main beam half-power beamwidth HPPBW0, the loaded main beam peak G1, the loaded main beam position B1, the loaded left first sidelobe level LSSL1, the loaded right first sidelobe level RSLL1 and the loaded main beam half-power beamwidth HPPBW1, obtain the electrical performance of the array antenna after being loaded with the high-temperature ablation antenna cover; wherein, the electrical performance of the array antenna after being loaded with the high-temperature ablation antenna cover includes: aiming error BSE, maximum gain loss TLM, left first sidelobe level loss TLL, right first sidelobe level loss TLR and main beam half-power beamwidth loss TLB.

[0102] Specifically, for the aiming error BSE, BSE = |B0-B1|;

[0103] For the maximum gain loss TLM, TLM = |TLM0-TLM1|;

[0104] For the left first sidelobe level loss TLL, TLL = |TSLL0-TSLL1|;

[0105] For the right first sidelobe level loss TLR, TLR = |RSLL0-RSLL1|;

[0106] For the main beam half-power beamwidth loss TLB, TLB=|HPBW0-HPBW1|.

[0107] S8: Based on the phase distribution of the antenna array and the electrical performance of the array antenna after being loaded with a high-temperature ablation radome, an optimization design model is established. Using the particle swarm optimization algorithm in MATLAB, the optimization design model is iterated for the maximum number of times to obtain the optimized phase distribution of the array antenna.

[0108] Specifically, for S8, it may include:

[0109] S81: Develop an optimization design model based on the phase distribution of the antenna array and the electrical performance of the array antenna after loading a high-temperature ablation radome. This may include:

[0110] The phase distribution of each array element in the array antenna obtained in step S5 is used as the design variable, and the aiming error BSE, maximum gain loss TLM, left first sidelobe level loss TLL, right first sidelobe level loss TLR, and main beam half-power beamwidth loss TLB obtained in step S7 are used as the design targets to establish an optimization design model. The optimization design model is as follows:

[0111]

[0112] Among them, φ n Represents the phase distribution of the nth array element in the antenna array, -180°≤φ n ≤180°, n=1,2,…,N, BSE1 represents the pointing error caused by the radome under the specified flight condition, TLM1 represents the maximum gain loss caused by the radome under the specified flight condition, TLL1 represents the left first sidelobe level loss caused by the radome under the specified flight condition, TLR1 represents the right first sidelobe level loss caused by the radome under the specified flight condition, TLB1 represents the main beam half-power beamwidth loss caused by the radome under the specified flight condition, BSE0, TLM0, TLL0, TLR0 and TLB0 represent the normalization coefficients corresponding to the electrical performance of the array antenna under the specified flight condition.

[0113] S82, using the particle swarm optimization algorithm through MATLAB, iterate the optimization design model for the maximum number of iterations to obtain the optimized array antenna phase distribution.

[0114] Specifically, using the particle swarm optimization algorithm in MATLAB, an iterative process of performing a maximum number of iterations on the optimization design model includes:

[0115] The phase distribution of all array elements in the antenna array is regarded as a particle swarm, and each phase distribution is regarded as a particle. For each particle in the particle swarm, the fitness value of the particle is obtained using the optimization design model.

[0116] The best fitness value among all particles is selected as the optimal individual fitness value. If the optimal individual fitness value is better than the optimal individual fitness value obtained in the previous iterative processing process, the individual optimal position and global optimal position of the particle swarm are updated according to the update formula, and the updated individual optimal position and global optimal position of the particle swarm are used for the next iterative processing process.

[0117] The particle velocity and position update formulas are standard formulas and will not be repeated here. For details, please refer to the existing relevant technical introduction.

[0118] It is understood that the fitness value can be a weighted sum of the aiming error and transmission loss. The transmission loss can include: maximum gain loss, left first sidelobe level loss, right first sidelobe level loss, and main beam half-power beamwidth loss. If the maximum number of iterations is set to 200, then 200 corresponding iterations will be performed in step S8 to obtain the optimized array antenna phase distribution for determination in step S9.

[0119] S9: Based on the electrical performance requirements of the antenna design, determine whether the change in the electrical performance of the optimized antenna meets the preset requirements. If so, output the optimized phase distribution of the array antenna; otherwise, adjust the particle swarm optimization parameters and repeat steps S5 to S9 until the preset requirements are met.

[0120] Understandably, Figure 2As shown, after the optimized array antenna phase distribution is obtained in step S8, step S9 determines whether the change in the electrical performance of the optimized antenna meets the preset requirements based on the electrical performance requirements of the antenna design. If the requirements are met, the optimized array antenna phase distribution is confirmed to meet the requirements. The optimized array antenna phase distribution is then output and the corresponding design scheme is selected as the optimal design scheme. If the requirements are not met, the particle swarm optimization parameters and / or the weights corresponding to each variable in the optimization design model can be adjusted, and steps S5 to S9 are repeated until the change in the electrical performance of the optimized antenna obtained in step S8 meets the preset requirements. The change in the electrical performance of the antenna refers to the electrical performance of the array antenna after the high-temperature ablation radome is installed. The preset requirements can be aiming error (BSE) < 0.3°, maximum gain loss (TLM) < 0.5dB, left first sidelobe level loss (TLL) < 1dB, right first sidelobe level loss (TLR) < 1dB, and main beam half-power beamwidth loss (TLB) < 1°. For ease of understanding, a simulation experiment is conducted below on the electrical performance compensation method for a high-temperature ablation radome based on array element phase adjustment provided in an embodiment of the present invention, so as to more clearly demonstrate the beneficial effects of the embodiment of the present invention.

[0121] Set simulation parameters: The structural diagram of an aircraft radome is as follows: Figure 3 As shown, the array antenna is 300 mm from the bottom of the radome. A total of 1×16 electric dipoles are arranged on the array surface with a spacing of λ / 2, where λ represents the operating wavelength. The operating frequency can be 9.4 GHz. The initial phase of the array elements can be uniform and in phase, and the scanning angle can be 10°. The outer wall diameter of the radome bottom can be 500 mm, the inner wall diameter can be 467.28 mm, and the height can be 1000 mm. The material can be quartz glass, and the dielectric constant of the material at room temperature can be 3.8 and the loss tangent can be 0.0005. The flight conditions of the aircraft can be: a flight altitude of 10 km, a flight speed of 7 Ma, and an angle of attack of 12°.

[0122] In the commercial software FLUENT, the aerodynamic thermal analysis of the aircraft radome is carried out. First, the fluid grid of the aircraft radome is divided, such as Figure 4 As shown, the incoming flow boundary condition is set to pressure far field, and the outlet boundary condition is set to pressure outlet. The incoming flow Mach number, air temperature, pressure and direction are determined by the flight speed, flight altitude and angle of attack respectively. The temperature distribution on the outer surface of the radome is obtained as shown in Figure 5 shown.

[0123] The temperature distribution data of the outer surface of the radome is extracted from the simulation results of Fluent. The data format is a data table. The first column of the table is the x-coordinate of the radome grid node, the second column is the y-coordinate, and the third column is the temperature value of the corresponding grid node. Figure 6a-6dThe radome material parameter curve shown is extracted as a data table. The first column is the temperature value, and the second column is the material parameter value corresponding to the current temperature. The above data table is imported into COMSOL to construct the temperature interpolation function T(x,y), thermal conductivity interpolation function Q(T), and specific heat capacity interpolation function C P (T), dielectric constant interpolation function epu(T) and loss tangent interpolation function loss(T), for dielectric constant interpolation function epu(T) and loss tangent interpolation function loss(T), extrapolation interpolation is adopted, that is, when the temperature exceeds the ablation temperature, the dielectric constant is extrapolated to 1 and the loss tangent is extrapolated to 0. The part of the radome where the temperature exceeds the ablation temperature is regarded as an air hood to simulate the state of radome ablation. In the radome material parameter setting in the commercial software COMLOL, the thermal conductivity is set to Q(T) and the specific heat capacity is set to C P (T), the dielectric constant is set to epu(T), the loss tangent is set to loss(T), and the temperature boundary condition is set to T(x,y) in the boundary condition setting to obtain the finite element model of the high-temperature ablation antenna cover.

[0124] Initialize the phase distribution of the array antenna, use COMSOL to calculate the electrical performance of the array antenna before and after adding the high-temperature ablation antenna cover, use COMSOL Multiphysics with MATLAB interface to extract the electrical performance indicators, build the optimization design model, and use the particle swarm optimization algorithm to solve the optimization model. The phase optimization results are as follows: Figure 7 The corresponding electrical performance indicators are shown in Table 1, which shows the comparison of electrical performance of the antenna cover before and after compensation.

[0125] Table 1 Comparison of electrical performance of radome before and after compensation

[0126] state BSE(°) TLM(dB) TLL(dB) TLR(dB) TLB(°) Uncompensated 1.33 0.91 2.78 4.48 0.73 Compensation 1 0.48 2.06 6.6 6.23 1.23 Compensation 2 0.02 2.14 0 0.02 0.71

[0127] Figure 7 In the example, Optimization 1 represents the phase distribution scheme obtained by the existing compensation method based on geometric optics, and Optimization 2 represents the phase distribution scheme obtained by the electrical performance compensation method of the high-temperature ablation radome based on array element phase adjustment provided by an embodiment of the present invention. Figure 8 To compensate for the directional patterns of the front and rear array antennas, Figure 8 The comparison of antenna patterns under the corresponding optimization methods can be seen in Figure 2.

[0128] from Figure 7As can be seen from Table 1, the electrical performance of the high-temperature ablation radome deteriorates seriously, which is reflected in the maximum gain loss of 0.91 dB, the aiming error of 1.33°, the left first sidelobe level loss of 2.78 dB, the right first sidelobe level loss of 4.48 dB, and the half-power beamwidth loss of 0.73°. It can be seen that the existing compensation method based on geometric optics can only provide approximate compensation and the effect is not significant. By adopting the compensation method provided by the present invention, the electrical performance indicators are well improved.

[0129] The method for compensating the electrical performance of a high-temperature ablation radome based on array element phase adjustment, provided in an embodiment of the present invention, is based on data on the temperature distribution of the radome in an operating environment and the temperature-dependent changes in its material properties. When establishing a finite element model of the high-temperature ablation radome, the portion of the radome whose temperature exceeds the ablation temperature is reconstructed as an air radome, thereby obtaining a finite element model of the high-temperature ablation radome. A full-wave calculation using COMLOL is performed to determine the electrical performance of the array antenna after loading the high-temperature ablation radome. The optimal phase distribution of the array antenna within the radome is iteratively solved using a particle swarm optimization algorithm, thereby compensating for the effects of high-temperature ablation on the radome's electrical performance. This method not only ensures compensation accuracy but also takes into account the effects of high-temperature ablation on the radome's electrical performance. The method exhibits high compensation effectiveness and accuracy, and has wide applicability.

[0130] It should be noted that, in the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0131] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention are included in the scope of protection of the present invention.

Claims

1. A method for compensating the electrical performance of a high-temperature ablation radome based on array element phase adjustment, characterized in that: include: S1: Determine the structural parameters and material properties of the aircraft's radome; S2: determining the flight condition of the aircraft's radome according to the aircraft's flight curve; S3: Using the commercial software Fluent, a flow field and a fluid calculation grid model of the aircraft's radome are established based on the structural parameters and flight conditions, thereby obtaining temperature distribution data on the outer surface of the radome; S4: The temperature distribution data and material property data of the radome outer surface are imported into the commercial software COMLOL in the form of interpolation functions to construct a finite element model of the high-temperature ablation radome; S5: Using MATLAB, based on particle swarm optimization parameters, randomly generate the phase distribution of the antenna array inside the radome and specify the scanning angle of the antenna array; the particle swarm optimization parameters include: the number of individuals in the optimization population and the maximum number of iterations; S6: using commercial software COMLOL, obtaining a first far-field pattern of the array antenna based on the phase distribution and the scanning angle, and extracting electrical performance of the array antenna from the first far-field pattern; S7: Using the commercial software COMLOL, based on the finite element model, phase distribution, and scanning angle of the high-temperature ablative radome, a second far-field pattern of the array antenna after the high-temperature ablative radome is installed is obtained, thereby determining the electrical performance of the array antenna after the high-temperature ablative radome is installed; S8: establishing an optimization design model based on the phase distribution of the antenna array and the electrical performance of the array antenna after being loaded with a high-temperature ablation radome; and iterating the optimization design model for a maximum number of times using a particle swarm optimization algorithm in MATLAB to obtain an optimized phase distribution of the array antenna. S9: Based on the electrical performance requirements of the antenna design, determine whether the change in the electrical performance of the optimized antenna meets the preset requirements. If so, output the optimized array antenna phase distribution; otherwise, adjust the particle swarm optimization parameters and repeat steps S5 to S9 until the preset requirements are met.

2. The method for compensating electrical performance of a high-temperature ablation radome based on array element phase adjustment according to claim 1, characterized in that: The structural parameters of the radome include: The height, diameter, thickness of the radome and the distribution position of the array antenna inside the radome.

3. The method for compensating electrical performance of a high-temperature ablation radome based on array element phase adjustment according to claim 1, characterized in that: The material properties of the radome include: Thermal conductivity Q, specific heat capacity C P , curves showing changes in dielectric constant epu and loss tangent loss with temperature.

4. The method for compensating electrical performance of a high-temperature ablation radome based on array element phase adjustment according to claim 1, characterized in that: The flight operating conditions of the radome include: The flight altitude, flight speed and angle of attack of the radome.

5. The method for compensating electrical performance of a high-temperature ablation radome based on array element phase adjustment according to claim 1, characterized in that: The temperature distribution data and material properties of the outer surface of the radome that change with temperature are imported into the commercial software COMLOL in the form of an interpolation function to construct a finite element model of the high-temperature ablation radome, including: The temperature distribution data was processed into a first data table with J rows and 3 columns using the commercial software Fluent. The format of the first data table is as follows: (x j ,y j ,T j ),j=1,2,…,J; Where j represents the jth grid node in the fluid calculation grid model of the radome, J represents the total number of grid nodes in the fluid calculation grid model, and x j ,y j represents the coordinates of the grid nodes, T j Indicates the temperature corresponding to the j-th grid node; Data on changes in material properties with temperature are extracted from the material properties of the radome, and the data on changes in material properties with temperature are processed into a second data table with K rows and 2 columns; the format of the second data table is as follows: (T k ,value k ),k=1,2,…,K; Where k represents the kth sampling point in the temperature curve of the radome material, K represents the total number of sampling points, and T k Indicates the temperature of the sampling point, value k Indicates the material parameter value corresponding to the kth sampling point; Import the first and second data tables into the interpolation function interface of the commercial software COMLOL to construct the temperature interpolation function T(x,y), thermal conductivity interpolation function Q(T), and specific heat capacity interpolation function C P (T), dielectric constant interpolation function epu(T) and loss tangent interpolation function loss(T), simulate the state of radome ablation; In the radome material parameter setting in the commercial software COMLOL, the thermal conductivity is set to Q(T) and the specific heat capacity is set to C P (T), the dielectric constant is set to epu(T), the loss tangent is set to loss(T), and the temperature boundary condition is set to T(x,y) in the boundary condition setting to obtain the finite element model of the high-temperature ablation antenna cover.

6. The method for compensating electrical performance of a high-temperature ablation radome based on array element phase adjustment according to claim 1, characterized in that: The method utilizes MATLAB to randomly generate the phase distribution of the antenna array in the radome based on particle swarm optimization parameters and specifies the scanning angle of the antenna array, including: The rand function in MATLAB is used to randomly generate the phase distribution of each array unit in the antenna array inside the radome. The number of array units is equal to the number of individuals in the optimization population in the particle swarm optimization parameters. The phase distribution of the array unit ranges from [-180° to 180°], and the scanning angle of the array unit is obtained by default.

7. The method for compensating electrical performance of a high-temperature ablation radome based on array element phase adjustment according to claim 6, characterized in that: The electrical properties of the array antenna include: Main beam peak G0, main beam position B0, left first sidelobe level LSSL0, right first sidelobe level RSLL0 and main beam half power beamwidth HPPBW0.

8. The method for compensating electrical performance of a high-temperature ablation radome based on array element phase adjustment according to claim 7, characterized in that: The method uses the commercial software COMLOL to obtain a second far-field pattern of the array antenna after the high-temperature ablative radome is installed based on the finite element model, phase distribution, and scanning angle of the high-temperature ablative radome, thereby determining the electrical performance of the array antenna after the high-temperature ablative radome is installed, including: Using the commercial software COMLOL and the finite element model of the high-temperature ablative radome, the phase distribution and scanning angle of the array element corresponding to each individual in the optimized population were simulated to obtain the second far-field pattern of the array antenna equipped with the high-temperature ablative radome. Using the COMSOL Multiphysics with MATLAB interface of the commercial software COMSOL and MATLAB co-simulation, the main beam peak G1 after loading the high-temperature ablation radome, the main beam position B1 after loading, the left first sidelobe level LSSL1 after loading, the right first sidelobe level RSLL1 after loading, and the main beam half-power beamwidth HPPBW1 after loading were extracted from the second far-field pattern; Based on the main beam peak G0, main beam position B0, left first sidelobe level LSSL0, right first sidelobe level RSLL0, main beam half-power beam width HPPBW0, loaded main beam peak G1, loaded main beam position B1, loaded left first sidelobe level LSSL1, loaded right first sidelobe level RSLL1 and loaded main beam half-power beam width HPPBW1, the electrical performance of the array antenna after loading the high-temperature ablation antenna cover is obtained; wherein, the electrical performance of the array antenna after loading the high-temperature ablation antenna cover includes: aiming error BSE, maximum gain loss TLM, left first sidelobe level loss TLL, right first sidelobe level loss TLR and main beam half-power beam width loss TLB.

9. The method for compensating electrical performance of a high-temperature ablation radome based on array element phase adjustment according to claim 1, characterized in that: The optimization design model is as follows: Among them, φ n represents the phase distribution of the nth array element in the antenna array, BSE1 represents the pointing error caused by the radome under the specified flight condition, TLM1 represents the maximum gain loss caused by the radome under the specified flight condition, TLL1 represents the level loss of the left first sidelobe caused by the radome under the specified flight condition, TLR1 represents the level loss of the right first sidelobe caused by the radome under the specified flight condition, TLB1 represents the main beam half-power beamwidth loss caused by the radome under the specified flight condition, BSE0, TLM0, TLL0, TLR0 and TLB0 represent the normalization coefficients corresponding to the electrical performance of the array antenna under the specified flight condition.

10. The method for compensating electrical performance of a high-temperature ablation radome based on array element phase adjustment according to claim 1, characterized in that: The particle swarm optimization algorithm is used in MATLAB to perform an iterative process of the maximum number of iterations on the optimization design model, including: The phase distributions of all array elements in the antenna array are regarded as a particle swarm, and each phase distribution is regarded as a particle; for each particle in the particle swarm, the fitness value of the particle is obtained using the optimization design model; The best fitness value among all particles is selected as the optimal individual fitness value. If the optimal individual fitness value is better than the optimal individual fitness value obtained in the previous iterative processing process, the individual optimal position and global optimal position of the particle swarm are updated according to the update formula, and the updated individual optimal position and global optimal position of the particle swarm are used for the next iterative processing process.

Images