Radar antenna assembly process optimization method based on error analysis

Abstract

The present application provides a radar antenna assembly process optimization method based on error analysis, including an analysis of the correlation between electrical performance and antenna unit errors and optimizing the assembly process using error analysis. The radar antenna assembly process optimization method based on error analysis provided in the present application reduces the influence of position errors after optimized sorting, and approaches the electric field value of the ideal position.

Description

Technical Field

[0001] The present application belongs to the technical field of radar antenna assembly, and more specifically, to a radar antenna assembly process optimization method based on error analysis. Background Art

[0002] Precision allocation is a very important part of antenna array structure design. Reasonably allocating the precision of each component of the antenna array, so that the antenna array system can meet the required performance indicators and minimize the system cost, is the basic goal of precision allocation. Array precision allocation ensures that the relative position of the radiating unit in the spatial coordinates can meet the telecommunications performance requirements, that is, the position accuracy of the radiating unit in the three directions of X / Y / Z. For the antenna array, the antenna arrangement form is positioned as an input variable, and the deformation of the radiating unit in the three directions of X / Y / Z is set as the output variable. Through precision allocation and simulation, the position tolerance of the array antenna is reasonably arranged, and sub-arrays with different tolerance ranges are allocated to appropriate positions, so that the impact of the mechanical assembly process on the telecommunications performance of the array is reduced.

[0003] The current antenna array assembly process mainly relies on manual assembly by assembly workers. The antenna assembly cycle is as long as several months, the work efficiency is low, and the operation process will inevitably produce random errors in the array element position that deviate from the ideal position. The existence of random errors will have a significant impact on the electrical performance of the antenna. Summary of the invention

[0004] To achieve the above objectives, the technical solution adopted in this application is: to provide a radar antenna assembly process optimization method based on error analysis, including correlation analysis of electrical performance and antenna unit errors and optimization of the assembly process using error analysis.

[0005] Optionally, the analysis of the correlation between electrical performance and antenna unit error includes the following steps:

[0006] Step S101: Calculation of array electrical performance;

[0007] Step S102: Calculate the array far-field pattern;

[0008] Step S103: Analyzing the sensitivity of the electric field of the array.

[0009] Optionally, in step S101, A uniform linear array composed of identical antenna elements, with a spacing of 1000 m between adjacent elements. , the array operating wavelength is The target wave direction is ;

[0010] For The excitation current of an antenna array element is expressed as:

[0011] (1)

[0012] in is the amplitude of the excitation current, is the phase difference of the excitation current of adjacent array elements, and the electric field strength generated by the antenna unit in the far radiation area It is expressed as:

[0013] (2)

[0015] in, is the electric field function of the antenna element, Indicates The distance from the array element to the target position,

[0016] The array factor of the antenna array is expressed as:

[0017] (3)

[0019] In the formula, Indicates that when the target is located The phase difference between adjacent antenna elements in a two-dimensional phased array antenna is an extension of a one-dimensional antenna.

[0020] Optionally, the array antenna is arranged in a triangular grid, and the array surface is located at Plane, by The antenna unit is composed of Axial spacing and The axial spacing is , , No. The excitation current of each array element is expressed as , its coordinate position is:

[0021] (4)

[0023] The pitch angle and rotation angle are used to represent the target's position, which is , then the distance between two adjacent antenna units is Axis and The phase differences of the axes are and , No. Array elements and reference elements The phase difference is:

[0024] (5)

[0026]

[0027] The phase shifter provides The phase of each antenna element is:

[0028] (6)

[0030] Therefore, the final triangular grid antenna pattern function is:

[0031] (7)

[0033]

[0034] Optionally, in step S102, the triangular grid arrangement is staggered, and the method adopted is to set the excitation current and apply the excitation current I to the rectangular array surface; the phased array antenna pattern of the triangular grid arrangement is simulated in a simulation environment, the electric field pattern of a single antenna unit is calculated by simulation software, and the array factor equation is calculated. The calculation includes two cases, one is the array factor pattern of the antenna unit in the ideal position, and the other is the array factor pattern after the position error is introduced. Finally, the array factor pattern of the entire array surface can be obtained by multiplying the electric field product of the two patterns.

[0035] Optionally, in step S103, since the antenna array includes hundreds of sub-arrays in total, the array tolerance sensitivity is calculated, the tolerance distribution of different positions is allocated, and then the sub-arrays with different position error ranges are placed at appropriate positions;

[0036] By taking the derivative of the field intensity pattern, the sensitivity of the electric field intensity of the array antenna to the position of the antenna unit can be obtained. The calculation model is:

[0037] (10)

[0038] (11)

[0040] (12)

[0041] Optionally, optimizing the assembly process using error analysis includes the following steps:

[0042] Step S201: Establishing an antenna unit position error model, concentrating the small errors at the center of the array, and rearranging the sub-arrays with position errors;

[0043] Step S202: Calculate the antenna far-field pattern.

[0044] Step S203: Simulation verification of the optimized assembly sequence.

[0045] Optionally, in step S202, the antenna array pattern is equal to the unit pattern multiplied by the array factor pattern. The antenna unit pattern is data derived from HFSS simulation calculation. The derived data is multiplied by the array factor pattern function to obtain the total electric field pattern of the antenna array calculated in the simulation environment. The array factor pattern includes three types:

[0046] (1) Array coordinate matrix of ideal position;

[0047] (2) Array coordinate matrix with random errors;

[0048] (3) The array coordinate matrix after sorting and optimization.

[0049] The above are the results calculated by the mathematical model. The three coordinate matrices are exported into txt text, and then imported into HFSS respectively. The array pattern is calculated by HFSS simulation, and the results correspond to the calculation results respectively:

[0050] (1) Array coordinate matrix of ideal position;

[0051] (2) Array coordinate matrix with random errors;

[0052] (3) The array coordinate matrix after sorting and optimization.

[0053] The coordinates of the square antenna and the diamond antenna were imported into HFSS.

[0054] The present invention provides a radar antenna assembly process optimization method based on error analysis. Based on the phased array radar antenna error model, a mathematical model of the phased array antenna pattern and the antenna unit position is established. On this basis, a normally distributed random error is introduced as the installation error of the antenna unit, and the change of the position error on the antenna electrical performance is observed. A sensitivity model based on the electric field strength is performed on the array, and the influence of the random error on different positions is quantitatively analyzed. Based on the sensitivity model, the array assembly sequence is optimized. and The results of planar simulation verification show that the optimized sorting reduces the impact of position errors and is close to the electric field value of the ideal position; it greatly shortens the assembly cycle and improves work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0056] Figure 1Schematic diagram of uniform linear array antenna;

[0057] Figure 2 Arrange the array antenna in a triangular grid;

[0058] Figure 3 Arrange phased array antennas in a triangular grid;

[0059] Figure 4 This is a comparison chart between the ideal position and the actual position of the antenna;

[0060] Figure 5 This is the calculation result diagram of the ideal position direction diagram;

[0061] Figure 6 This is the calculation result diagram of the position error direction map;

[0062] Figure 7 Assemble a three-dimensional schematic diagram for the antenna array;

[0063] Figure 8 Provide a two-dimensional schematic diagram for antenna array assembly;

[0064] Fig. 9 is the mathematical model of field intensity sensitivity;

[0065] Fig.10 is the position error in the x direction;

[0066] Fig.11 is the random error in the y direction;

[0067] Fig.12 is the error distribution diagram after sorting;

[0068] Fig.13 is the square antenna array factor pattern;

[0069] Fig.14 Import process diagrams for parameters;

[0070] Fig.15 This is the HFSS calculation result diagram;

[0071] Fig.16 Introducing random errors into the error model for the triangular arrangement;

[0072] Fig.17 Comparison chart between HFSS and MATLAB for square antenna array optimization; DETAILED DESCRIPTION

[0073] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0074] The radar antenna assembly process optimization method based on error analysis provided in the embodiment of the present application is now described. The method includes correlation analysis between electrical performance and antenna unit errors and optimization of the assembly process using error analysis.

[0075] The analysis of the correlation between electrical performance and antenna unit errors includes the following steps:

[0076] Step S101: Calculate the electrical performance of the array, such as Figure 1 Shown is a A uniform linear array composed of identical antenna elements, with a spacing of 1000 m between adjacent elements. , the array operating wavelength is The target wave direction is .

[0077] For The excitation current of an antenna array element is expressed as:

[0078] (1)

[0079] in is the amplitude of the excitation current, is the phase difference of the excitation current of adjacent array elements. The electric field strength generated by the antenna unit in the far radiation area It is expressed as:

[0080] (2)

[0082] in, is the electric field function of the antenna element, Indicates The distance from the array element to the target position.

[0083] The array factor of the antenna array is expressed as:

[0084] (3)

[0086] In the formula, Indicates that when the target is located When the phase difference between adjacent antenna elements is in the same direction, the two-dimensional phased array antenna is an extension of the one-dimensional one. Common two-dimensional phased array antenna element arrangements include rectangular grid arrangement and triangular grid arrangement. The specific arrangement forms are as follows: Figure 2 shown.

[0087] Figure 2 It is a triangular grid array antenna, with the array surface located at Plane, by The antenna unit is composed of Axial spacing and The axial spacing is , , No. The excitation current of each array element is expressed as , whose coordinate position is

[0088] (4)

[0090] The pitch angle and rotation angle are used to represent the target's position, which is , then the distance between two adjacent antenna units is Axis and The phase differences of the axes are and . No. Array elements and reference elements The phase difference is:

[0091] (5)

[0092]

[0093] The phase shifter provides The phase of each antenna element is:

[0094] (6)

[0096] Therefore, the final triangular grid antenna pattern function is:

[0097] (7)

[0099]

[0100] Step S102: Calculate the far-field pattern of the array. The triangular grid arrangement is staggered. The method used is to set the excitation current and apply the excitation current I shown in (8) to the rectangular array.

[0101] (8)

[0103] The phased array antenna pattern of the triangular grid arrangement is simulated in the simulation environment. The simulation conditions are as follows: the spacing between adjacent antenna elements is , , the number of corresponding antenna array elements is 32x32, and the array elements are arranged as follows Figure 3 shown.

[0104] Array pattern calculation formula:

[0105] (9)

[0106] Where: is the total electric field pattern of the array (E total);

[0107] is the electric field pattern of a single antenna unit (E single);

[0108] is the array factor pattern (Array Factor).

[0109] The electric field pattern of a single antenna unit is calculated by simulation software, and the array factor equation is calculated. Two situations are calculated: one is the array factor pattern of the antenna unit in the ideal position, and the other is the array factor pattern after the position error is introduced. Finally, the array factor pattern of the entire array surface is obtained by multiplying the electric field of the two patterns.

[0110] The comparison between the ideal unit position and the actual unit position is shown in the figure below. Figure 4 As shown in the figure, the solid line is the actual installation position of the antenna unit, and the dotted line is the ideal installation position of the antenna unit. The position error generated during assembly makes some units close to each other, while the distance between some units is greater than the standard value.

[0111] Put the error data shown in Table 1 into the mathematical calculation model, and the calculation results are as follows Figure 6 As shown, through Figure 5 Comparing the calculation results of the ideal position pattern, it can be seen that the existence of position error will indeed have a significant impact on the antenna pattern.

[0112] Table 1 Position error parameters of input model

[0113]

[0114] Step S103: Array electric field sensitivity analysis,

[0115] Since the entire antenna array contains hundreds of sub-arrays, the array tolerance sensitivity is calculated, the tolerance distribution of different positions is allocated, and then the sub-arrays with different position error ranges are placed at appropriate locations.

[0116] The actual antenna unit will inevitably have assembly deviations that are inconsistent with the expected ones during the assembly process, as follows Figure 7 , Figure 8 The figure shows the deviation between the center of the antenna aperture and the actual theoretical center. The study places these sub-arrays with different deviations at appropriate positions on the array surface to optimize the electrical performance.

[0117] By taking the derivative of the field intensity pattern, the sensitivity of the electric field intensity of the array antenna to the position of the antenna unit can be obtained. The calculation model is:

[0118] (10)

[0119] (11)

[0121] (12)

[0122] Taking the array antenna parameters as input, the maximum field strength value of the radiation field is subjected to sensitivity analysis. The results obtained by using the mathematical model are as follows: Fig. 9 shown.

[0123] Depend on Fig. 9 It can be concluded that the closer to the center of the array, the stricter the position error requirement, and the error range at the edge of the array can be looser. After quantitative calculation, the antenna subarray with position error will be rearranged.

[0124] Optimizing the assembly process using error analysis includes the following steps:

[0125] Step S201: Establish an antenna unit position error model. The radar model is triangularly distributed. Random errors are introduced into the array antenna unit distribution to prove the rationality of the model. The position error of normal distribution is generated by random numbers, such as Fig.10 , Fig.11 As shown. The small errors are concentrated at the center of the array, and the sub-arrays with position errors are rearranged, as shown in Fig.12 shown.

[0126] Step S202: Calculate the antenna far-field pattern.

[0127] This step calculates and verifies the square antenna array. The square antenna unit array uses 44*99 units in this calculation. The unit spacing in the x direction is 31.6mm, the spacing in the y direction is 29mm, and the wavelength is 20mm. The parameters are input into the mathematical model of the antenna. The horizontal coordinate of the array factor pattern is , the vertical axis is , this pattern sets the beam pitch angle to , radar unit analysis generally selects and Two planes. Fig.13 The figure shows the square antenna array factor radiation pattern after the random error is introduced. It can be seen from the figure that the sidelobe level of the array factor radiation pattern after the random error is introduced is improved.

[0128] The antenna array pattern is equal to the unit pattern multiplied by the array factor pattern. The antenna unit pattern is the data derived from the HFSS simulation calculation. The derived data is multiplied by the array factor pattern function to obtain the total electric field pattern of the antenna array calculated in the simulation environment. There are three types of array factor patterns:

[0129] (1) Array coordinate matrix of ideal position;

[0130] (2) Array coordinate matrix with random errors;

[0131] (3) The array coordinate matrix after sorting and optimization.

[0132] The above are the results calculated by the mathematical model. The three coordinate matrices are exported into txt text, and then imported into HFSS respectively. The array pattern is calculated by HFSS simulation, and the results correspond to the calculation results respectively:

[0133] (1) The array coordinate matrix of the ideal position, namely HFSS_normal in the figure;

[0134] (2) The array coordinate matrix with random errors, i.e. HFSS_error in the figure;

[0135] (3) The array coordinate matrix after sorting and optimization, namely HFSS_error_order in the figure.

[0136] The square antenna coordinates are imported into the HFSS experimental process as follows Fig.14 shown.

[0137] The calculation results in HFSS are as follows Fig.15 As shown, (a) is the unit radiation pattern of the square antenna; (c) is the array radiation pattern after importing the ideal position coordinates; (e) is the array radiation pattern after importing the coordinates with random errors; (g) is the array radiation pattern after importing the sorted and optimized coordinates.

[0138] Step S203: After optimization, the assembly sequence is simulated and verified. The calculation results of the square antenna and the results of the HFSS calculation are plotted at the same time for comparison. Fig.16 As shown, where (a) is Plane comparison diagram, where (b) is Plane comparison diagram. From (a) and (b), it can be seen that the sidelobe level of the square antenna is reduced after sorting optimization.

[0139] Draw the ideal coordinate position and radiation pattern of the square antenna at the same time for comparison, such as Fig.17 As shown, (a) is Plane comparison diagram, where (b) is Plane comparison diagram. From (a) and (b), it can be seen that the sidelobe level of the square antenna after sorting optimization is close to the sidelobe level value of the ideal position.

[0140] The present invention provides a radar antenna assembly process optimization method based on error analysis. Based on the phased array radar antenna error model, a mathematical model of the phased array antenna pattern and the antenna unit position is established. On this basis, a normally distributed random error is introduced as the installation error of the antenna unit, and the change of the position error on the antenna electrical performance is observed. A sensitivity model based on the electric field strength is performed on the array, and the influence of the random error on different positions is quantitatively analyzed. Based on the sensitivity model, the array assembly sequence is optimized. and Planar simulation verification results show that the optimized sorting reduces the impact of position errors and is close to the electric field value at the ideal position.

[0141] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A radar antenna assembly process optimization method based on error analysis, characterized in that: Including the correlation analysis between electrical performance and antenna unit errors and the optimization of the assembly process using error analysis; The analysis of the correlation between electrical performance and antenna unit errors includes the following steps: Step S101: Calculation of array electrical performance; Step S102: Calculate the array far-field pattern; Step S103: Array electric field sensitivity analysis; In step S103, since the antenna array includes hundreds of sub-arrays in total, the array tolerance sensitivity is calculated, the tolerance distribution of different positions is allocated, and then the sub-arrays with different position error ranges are placed at appropriate positions; By taking the derivative of the field intensity pattern, the sensitivity of the electric field intensity of the array antenna to the position of the antenna unit can be obtained. The calculation model is: （10） （11） （12）； Optimizing the assembly process using error analysis includes the following steps: Step S201: Establishing an antenna unit position error model, concentrating the small errors at the center of the array, and rearranging the sub-arrays with position errors; Step S202: Calculate the antenna far-field pattern. Step S203: Simulation verification of the optimized assembly sequence.

2. The radar antenna assembly process optimization method based on error analysis as claimed in claim 1, characterized in that: In step S101, A uniform linear array composed of identical antenna elements, with a spacing of 1000 m between adjacent elements. , the array operating wavelength is The target wave direction is ; For The excitation current of an antenna array element is expressed as: （1） in is the amplitude of the excitation current, is the phase difference of the excitation current of adjacent array elements, and the electric field strength generated by the antenna unit in the far radiation area It is expressed as: （2） in, is the electric field function of the antenna unit, Indicates The distance from the array element to the target position, The array factor of the antenna array is expressed as: （3） In the formula, Indicates that when the target is located The phase difference between adjacent antenna elements in a two-dimensional phased array antenna is an extension of a one-dimensional antenna.

3. The radar antenna assembly process optimization method based on error analysis as claimed in claim 1, characterized in that: The triangular grid array antenna is located at Plane, by The antenna unit is composed of Axial spacing and The axial spacing is , , No. The excitation current of each array element is expressed as , its coordinate position is: （4） The pitch angle and rotation angle are used to represent the target's position, which is , then the distance between two adjacent antenna units is Axis and The phase differences of the axes are and , No. Array elements and reference elements The phase difference is: （5） The phase shifter provides The phase of each antenna element is: （6） Therefore, the final triangular grid antenna pattern function is: （7） 。 4. The radar antenna assembly process optimization method based on error analysis as claimed in claim 1, characterized in that: In step S102, the triangular grid arrangement is staggered, and the method used is to set the excitation current and apply the excitation current I to the rectangular array surface; the phased array antenna pattern of the triangular grid arrangement is simulated in a simulation environment, and the electric field pattern of a single antenna unit is calculated by simulation software. The array factor equation calculation includes two cases, one is the array factor pattern of the antenna unit in the ideal position, and the other is the array factor pattern after the position error is introduced. Finally, the array factor pattern of the entire array surface can be obtained by multiplying the electric field product of the two patterns.

5. The radar antenna assembly process optimization method based on error analysis as claimed in claim 1, characterized in that: In step S202, the antenna array pattern is equal to the unit pattern multiplied by the array factor pattern. The antenna unit pattern is the data derived from the HFSS simulation calculation. The derived data is multiplied by the array factor pattern function to obtain the total electric field pattern of the antenna array calculated in the simulation environment. The array factor pattern includes three types: (1) Array coordinate matrix of ideal position; (2) Array coordinate matrix with random errors; (3) The array coordinate matrix after sorting and optimization; The above are the results calculated by the mathematical model. The three coordinate matrices are exported into txt text, and then imported into HFSS respectively. The array pattern is calculated by HFSS simulation, and the corresponding results are as follows: (1) Array coordinate matrix of ideal position; (2) Array coordinate matrix with random errors; (3) The array coordinate matrix after sorting and optimization; The antenna coordinates are imported into HFSS.

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