Phased array radar far-field beam forming system and beam forming method

Abstract

The invention provides a phased array radar far-field beam forming system and a beam forming method, belongs to the technical field of phased array radars, and solves the problem that a large amount of time and operation resources need to be consumed in the simulation verification process of a traditional phased array antenna and an antenna housing. The forming system comprises an amplitude weighted array generation module, an array topological structure design look-up table database, a software module and an antenna array simulation module. The software module comprises a human-computer interface sub-module, an input data sub-module, a program calling sub-module and a data output sub-module which are connected in sequence; the amplitude weighting array generation module, the array topological structure design look-up table database and the antenna array simulation module are in bidirectional communication connection with the program calling sub-module; the antenna array simulation program comprises a beam pointing control sub-module, a phase weighting array generation sub-module, an array beam simulation sub-module and a simulation parameter output sub-module which are connected in sequence.

Description

Technical Field

[0001] The present invention relates to a phased array radar far - field beamforming system and a beamforming method, belonging to the technical field of phased array radars. Background Art

[0002] A phased array antenna can control the amplitude and phase of each unit of the antenna array to realize the regulation of the amplitude - phase distribution of the array, and then make the array beam reach the expected shaped state. In the actual application of phased array antennas, according to the requirements of the application scenario, an antenna radome structure is often added. The radome isolates the radar antenna from the external environment, forms a relatively enclosed space inside, protects the radar antenna inside from external harsh environment interference, makes the use and maintenance of the antenna array surface more convenient, improves the reliability of electronic devices, and extends the service life of the radar. However, due to the structure and material of the radome itself, it will affect the radiation characteristics of the internal antenna. Therefore, in the process of designing a phased array antenna and its radome, it is necessary to simulate the antenna array beam and the influence of the radome on the internal antenna.

[0003] Traditional phased array antenna and radome designs often start from the array units. According to the required array far - field beam parameters, a reasonable array topology structure design and feed circuit design are carried out. After completing the corresponding structure and parameter designs, simulation verification is carried out through simulation software. This process often requires a large amount of time and computing resources. Summary of the Invention

[0004] The present invention aims to solve the problem that a large amount of time and computing resources are required in the simulation verification process of traditional phased array antennas and radomes, and further proposes a phased array radar far - field beamforming system and a beamforming method.

[0005] The technical solution adopted by the present invention to solve the above problems is: A phased array radar far - field beamforming system proposed by the present invention includes an amplitude - weighted array generation module, a look - up table database for array topology structure design, a software module, and an antenna array simulation module;

[0006] The software module is used to provide a user input data page and a man - machine interaction page, call different modules, and output the calculation results of the amplitude - weighted array generation module, the look - up table database for array topology structure design, and the antenna array simulation module as the overall array beam regulation design scheme;

[0007] The amplitude - weighted array generation module calculates the amplitude - weighted array required for the corresponding beam shaping according to the amplitude - weighted matrix of the user - input data by using the non - separable Chebyshev matrix and transmits it to the software module;

[0008] The look-up table database for array topology structure design obtains high-dimensional matrix data obtained by linearly fitting the relationship between the array topology structure, the main lobe width of the array beam, and the main-to-side lobe gain according to the user's requirement for the array scale, and performs look-up to obtain the array topology structure design scheme and transmit it to the software module;

[0009] The antenna array simulation module is used to simulate and verify the array topology structure design scheme, obtain the phase weighting matrix in the design scheme through the beam pointing control calculation relationship of the phased array, output the antenna far-field pattern required for the corresponding scheme and transmit it to the software module.

[0010] Preferably, the software module includes a human-machine interface sub-module, an input data sub-module, a program call sub-module, and a data output sub-module connected in sequence;

[0011] The human-machine interface sub-module is used for human-machine interaction;

[0012] The input data sub-module is used to receive the expected index data of the antenna array input by the user, where the expected index data of the antenna array includes the expected main lobe width of the array, the main lobe gain, the side lobe gain, and the array scale;

[0013] The program call sub-module is used to design the overall array beam control scheme for the amplitude weighting array generation module, the look-up table database for array topology structure design, and the antenna array simulation module;

[0014] The data output sub-module is used to output the overall array beam control design scheme.

[0015] Preferably, the amplitude weighting array generation module, the look-up table database for array topology structure design, and the antenna array simulation module are all bidirectionally communicatively connected to the program call sub-module.

[0016] Preferably, the antenna array simulation program includes a beam pointing control sub-module, a phase weighting array generation sub-module, an array beam simulation sub-module, and a simulation parameter output sub-module connected in sequence;

[0017] The beam pointing control sub-module is used to calculate the beam pointing control relationship of the phased array;

[0018] The phase weighting array generation sub-module is used to calculate the phase distribution relationship, and combine it with the beam pointing control relationship of the phased array to obtain the phase weighting matrix of the array topology structure design scheme;

[0019] The array beam simulation sub-module is used to calculate the antenna far-field pattern required for the array topology structure design scheme;

[0020] The simulation parameter output sub-module is used to transmit the phase weighting matrix and the antenna far-field pattern to the software module.

[0021] A far-field beamforming method for a phased array radar, comprising:

[0022] Step 1: The user inputs the expected array size, main lobe width, main lobe gain, and sidelobe gain through the human-machine interface sub-module and the data input sub-module;

[0023] Step 2: The program call sub-module calls the amplitude weighting array generation module. According to the amplitude weighting matrix of the user input data, the amplitude weighting array required for the corresponding beamforming is calculated using the non-separable Chebyshev matrix and transmitted to the software module;

[0024] Step 3: The program call sub-module calls the array topology design look-up table database. According to the expected array size, main and sidelobe gains, and main lobe width, the element spacing parameter of the array is obtained by querying the high-dimensional matrix obtained by fitting the linear relationship between the array topology and the corresponding parameters, and the array topology design scheme is obtained and transmitted to the software module;

[0025] Step 4: The program call sub-module calls the antenna array simulation module to simulate the obtained amplitude weighting array and the array topology design scheme;

[0026] Step 5: The phase weighting matrix in the design scheme is obtained through the beam pointing control sub-module, the phase weighting array generation sub-module, and the array beam simulation sub-module, and the corresponding required antenna far-field pattern is output and transmitted to the software module through the simulation parameter output sub-module;

[0027] Step 6: The software module takes the received amplitude weighting matrix, phase weighting matrix, and the array topology design scheme as the overall array beam regulation design scheme and outputs it through the data output sub-module.

[0028] The beneficial effects of the present invention are:

[0029] (1) The present invention can adjust the control of different array beam parameters according to different array sizes and application requirements, including the main lobe width, main lobe gain, sidelobe gain, and beam pointing, and can adjust the simulation accuracy according to different requirements to achieve a balance between the simulation speed and accuracy requirements.

[0030] (2) The present invention can quickly give the corresponding array far-field pattern according to the required parameters and give the corresponding array design scheme for verification work such as radome design, saving the required resources and time to a certain extent.

[0031] (3) The present invention uses an inseparable Chebyshev matrix to regulate the main and side lobe gains of the far-field beam of the array. Compared with the regulation scheme obtained by the traditional Chebyshev matrix, which can only achieve Chebyshev distribution and corresponding gain control in the horizontal and vertical directions, the present invention has the characteristics that it is in Chebyshev distribution under any cross-section in the beam pointing direction and can ensure the gain control effect at the same time.

[0032] (4) The present invention can be adapted to various types of array element antennas. By importing the far-field pattern of the corresponding array element antenna, the present invention can design a control scheme according to its specific characteristic parameters to adapt to the corresponding array. Description of the Drawings

[0033] Figure 1 is a structural block diagram of a phased array radar far-field beamforming system provided by the present invention;

[0034] Figure 2 is a schematic diagram of the inseparable Chebyshev matrix distribution provided by the present invention, Figure 2 in which, (a) is a schematic diagram of the current distribution weighting matrix of the array, and (b) is the far-field pattern of the array;

[0035] Figure 3 is a schematic diagram of the main and side lobe gain control effect provided by the present invention;

[0036] Figure 4 is a schematic diagram of the main lobe width control effect provided by the present invention;

[0037] Figure 5 is a schematic diagram of the control effect when the beam pointing is -30° in the horizontal direction provided by the present invention;

[0038] Figure 6 is a schematic diagram of the control effect when the beam pointing is 10° in the horizontal direction and -20° in the elevation direction provided by the present invention;

[0039] Figure 7 is a schematic flow diagram of a phased array radar far-field beamforming method provided by the present invention. Detailed Embodiments

[0040] Detailed Embodiment 1: As Figure 1 shown, the structure of a phased array radar far-field beamforming system described in this embodiment includes:

[0041] an amplitude weighting array generation module, an array topology structure design look-up table database, a software module, and an antenna array simulation module;

[0042] The amplitude weighted array generation module calculates the amplitude weighted array required for corresponding beamforming according to the amplitude weighted matrix of the user input data by using the non-separable Chebyshev matrix and transmits it to the software module;

[0043] The array topology design look-up table database looks up the high-dimensional matrix data obtained by linearly fitting the relationship between the array topology, the main lobe width of the array beam, and the main and side lobe gains according to the user's requirement for the array scale, and obtains the array topology design scheme and transmits it to the software module;

[0044] The software module includes a human-machine interface sub-module, an input data sub-module, a program call sub-module, and a data output sub-module connected in sequence, which is used to provide a user input data page and a human-machine interaction page, call different modules, and output the calculation results of the amplitude weighted array generation module, the array topology design look-up table database, and the antenna array simulation module as the overall array beam control design scheme. The amplitude weighted array generation module, the array topology design look-up table database, and the antenna array simulation module are all connected to the program call sub-module for two-way communication.

[0045] The human-machine interface sub-module is used for human-machine interaction; the input data sub-module is used to receive the expected index data of the antenna array input by the user, where the expected index data of the antenna array includes the expected main lobe width of the array, the main lobe gain, the side lobe gain, and the array scale; the program call sub-module is used to design the overall array beam control scheme for the amplitude weighted array generation module, the array topology design look-up table database, and the antenna array simulation module; the data output sub-module is used to output the overall array beam control design scheme.

[0046] The human-machine interface sub-module of the software module is divided into three functional areas, namely the input parameter area, the output parameter area, and the image display area; the functions of the input parameter area include inputting parameters such as the expected array size, main lobe width, main and side lobe gains, and beam pointing of the user, and can be selected at resolutions of 1 degree and 0.1 degree according to different requirements; the function of the output parameter area is to display the actual parameters of the array beam generated by the program, and output the specific array design scheme corresponding to the beam as a data file in the corresponding format; the function of the image display area is to visually display the array beam and the array design scheme generated by the program in the form of an image.

[0047] The antenna array simulation module includes a beam pointing control sub-module, a phase weighted array generation sub-module, an array beam simulation sub-module, and a simulation parameter output sub-module connected in sequence, which is used to simulate and verify the array topology design scheme, obtain the phase weighted matrix in the design scheme through the beam pointing control calculation relationship of the phased array, output the antenna far-field pattern required for the corresponding scheme and transmit it to the software module;

[0048] The beam pointing control sub-module is used to calculate the phased array beam pointing control relationship; the phase weighting array generation sub-module is used to calculate the phase distribution relationship, and combine with the phased array beam pointing control relationship calculation to obtain the phase weighting matrix of the array topology design scheme; the array beam simulation sub-module is used to calculate the antenna far-field pattern required by the array topology design scheme; the simulation parameter output sub-module is used to transmit the phase weighting matrix and the antenna far-field pattern to the software module.

[0049] Specific Embodiment 2: Combined with Figures 2-7 This embodiment is described as follows. As Figure 7 shown, the steps of a phased array radar far-field beamforming method described in this embodiment include:

[0050] S1: The user inputs the expected array scale, main lobe width, main lobe gain, and side lobe gain through the human-machine interface sub-module and the data input sub-module;

[0051] S2: The amplitude weighting array generation module is called through the program call sub-module. According to the amplitude weighting matrix of the user input data, the amplitude weighting array required for the corresponding beamforming is calculated using the non-separable Chebyshev matrix and transmitted to the software module;

[0052] Main and side lobe gain control: In this embodiment, the non-separable Chebyshev matrix is used to achieve the main and side lobe gain control of the antenna array far-field beam on any φ section. Among them, the Chebyshev polynomial is the solution of the Chebyshev differential equation, and its expression is:

[0053]

[0054] Its solution is:

[0055]

[0056] For T m (x0) = R, we can get:

[0057]

[0058] In formulas (1)-(3), m is the order of the polynomial, and R is the ratio of the main lobe value to the side lobe value;

[0059] For the traditional Chebyshev matrix distribution, the weighted distribution on the antenna array surface is separable, and the far-field pattern generated by the array is equivalent to the superposition of the patterns of two linear arrays in two perpendicular directions. Therefore, at this time, the array can only ensure that the current distributions in the directions of the two linear arrays conform to the Chebyshev distribution. However, in the pattern cross-sections outside these two directions, since the circuit distribution is the vector superposition of the two linear array directions in the cross-section direction, the directivity coefficient will be reduced to a certain extent and will not conform to the Chebyshev distribution with equal side lobes.

[0060] In this embodiment, an inseparable Chebyshev matrix is used for the inseparable design of the array current distribution, which can ensure that the current distribution in any cross-section conforms to the Chebyshev distribution, thereby achieving a more perfect control of the beam main lobe and side lobe gains.

[0061] The current distribution of the inseparable Chebyshev array can be expressed as:

[0062] For a planar array of M×M elements, when M = 2N:

[0063]

[0064] When M = 2N + 1:

[0065]

[0066] In formulas (4) and (5), N is any positive integer;

[0067] According to the main lobe and side lobe gain control logic of the array obtained from the inseparable Chebyshev matrix, taking an array of 64×64 elements as an example, when the main lobe gain and side lobe gain are set to arbitrary values respectively, according to the difference between the main lobe gain and the side lobe gain, the current distribution weighting matrix of the array as shown in Figure 2 (a) and the far-field pattern of the array as shown in Figure 2 (b) both conform to the inseparable Chebyshev distribution:

[0068] After determining the distribution of the array current weighting matrix through the difference between the main lobe gain and the side lobe gain, according to the specific value of the main lobe gain, the values of the current weighting matrix are raised as a whole to meet the specific requirements of the main lobe gain value.

[0069] For the verification of the main lobe and side lobe gain control effect, taking an array of 64×64 array elements as an example, to verify its control effect, for the convenience of data verification, in this embodiment, the side lobe gain is uniformly set to 0 dB, and the main lobe gains are set to 20 dB, 30 dB, 40 dB, 50 dB, and 60 dB respectively. The main lobe and side lobe gain control effect of the program is as shown in Figure 3 shown;

[0070] As can be seen from the implementation effect of the program, the array pattern conforms to the Chebyshev distribution with equal sidelobes, and the main lobe gain values are: 20.0422 dB, 30.0422 dB, 40.0422 dB, 50.0422 dB, 60.0422 dB, and the sidelobe gain controls are respectively: 0.0266 dB, 0.0266 dB, -0.0748 dB, -0.5662 dB, 0.0399 dB.

[0071] The present invention uses an inseparable Chebyshev matrix to regulate the main and sidelobe gains of the array far-field beam. Compared with the regulation scheme obtained by the traditional Chebyshev matrix, which can only achieve the Chebyshev distribution and the corresponding gain control in the horizontal and vertical directions, the present invention has the characteristics that it is a Chebyshev distribution in any cross-section in the beam pointing direction and can ensure the gain control effect at the same time.

[0072] S3: Call the array topology structure design look-up table database through the program call sub-module. According to the expected array scale, main and sidelobe gains, and main lobe width, obtain the element spacing parameters of the array by querying the high-dimensional matrix obtained by fitting the linear relationship between the array topology structure and the corresponding parameters, and obtain the array topology structure design scheme and transmit it to the software module;

[0073] Main lobe width control: In this embodiment, the high-dimensional matrix data obtained by linearly fitting the relationship between the array topology structure, the main lobe width of the array beam, and the main and sidelobe gains is looked up, so as to give the array topology structure design scheme and then realize the main lobe width control.

[0074] In this embodiment, the original main lobe width data of the array obtained after regulating the main and sidelobe gains is recorded, and it is integrated with the array topology structure data such as the array scale and element spacing into a high-dimensional matrix, and the corresponding relationship between the array topology structure data and the main lobe width is supported by a high-dimensional correspondence table through linear fitting, and based on the accurate main and sidelobe gain control according to the specific set data, the control of the main lobe width of the array pattern is further realized.

[0075] According to the relationship between the main lobe width and the array topology structure, the rough corresponding relationship between the array scale and the main lobe width control range is shown in Table 1:

[0076] Table 1

[0077] Array scale 2×2 4×4 8×8 16×16 32×32 64×64 128×128 Minimum width 28 12 4 2.2 1.1 0.5 0.2 Maximum width 60 34 20 10 6 3 1.4

[0078] Taking the 64×64 array as an example, the accuracy of the main lobe width regulation within the program adjustable range is verified. The main lobe width control effect of the program is as Figure 4As shown, from the program operation results, when the expected main lobe widths are set to 1°, 1.5°, 2°, and 2.5° respectively, the results generated by the program are 1.2°, 1.6°, 2°, and 2.6° respectively. Then the average control error of the program in the case of a 64×64 array is 7.6%. For arrays of other scales, the control errors from a 4×4 array to a 128×128 array are 2.6%, 2.5%, 5.2%, 7.6%, and 10.5% respectively. It can be seen that as the main lobe width decreases, there are certain limitations in the control accuracy of the program for the main lobe width.

[0079] S4: Call the antenna array simulation module through the program call sub-module, and simulate the obtained amplitude weighted array and the array topology structure design scheme;

[0080] S5: Obtain the phase weighted matrix in the design scheme through the beam pointing control sub-module, the phase weighted array generation sub-module, and the array beam simulation sub-module, output the corresponding required antenna far-field pattern, and transmit it to the software module through the simulation parameter output sub-module;

[0081] Beam pointing control: The beam pointing control of this embodiment is achieved by performing phase compensation between array elements in the pitch direction and the horizontal direction respectively. The relationship between the array beam pointing in a single direction and the phase difference between array elements is:

[0082]

[0083] In formula (6), θ is the beam pointing angle, is the phase difference between adjacent array elements, λ is the signal wavelength, and d is the array element spacing.

[0084] After determining the beam pointing in the pitch and horizontal directions, the overall beam pointing can be controlled through the vector sum of the two directions. Due to the limitations of the rectangular phased array structure itself, when the beam pointing is greater than a certain range, the far-field pattern of the array will be distorted. Therefore, the scanning range of the array designed by this program is limited to within ±30° in both the horizontal and pitch directions. The control effects are as follows:

[0085] When the beam pointing direction is set to -30° in the horizontal direction, the control effect is as Figure 5 shown. When the beam pointing is set to 10° in the horizontal direction and -20° in the pitch direction, the control effect is as Figure 6 shown. From the program control effects, it can be seen that when performing single-direction beam pointing control in the horizontal or pitch direction, the beam pointing control is relatively accurate. When the program performs two-dimensional space beam pointing control, the error term increases for one-dimensional control, but the overall is still within an acceptable range.

[0086] S6: The software module takes the received amplitude weighting matrix, phase weighting matrix, and the topological structure design scheme of the array as the overall array beam control design scheme and outputs it through the data output sub-module.

[0087] In summary, the present invention can adjust the parameters of different array beams according to different array scales and application requirements, including the main lobe width, main lobe gain, sidelobe gain, and beam pointing, and can adjust the simulation accuracy according to different requirements to achieve a balance between simulation speed and accuracy requirements. At the same time, the present invention can adapt to various types of array element antennas. By importing the far-field pattern of the corresponding array element antenna, the present invention can design a control scheme according to its specific characteristic parameters to adapt to the corresponding array.

[0088] The above are only the preferred embodiments of the present invention and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to form equivalent embodiments with equivalent changes. However, as long as it does not depart from the technical content of the present invention and is based on the spirit and principle of the present invention, any simple modification, equivalent replacement, and improvement of the above embodiments still fall within the protection scope of the technical solution of the present invention.

Claims

1. A far-field beamforming system for a phased array radar, characterized in that The structure of the phased array radar far-field beamforming system described above includes: an amplitude weighting array generation module, a look-up table database for array topology structure design, a software module, and an antenna array simulation module; The software module is used to provide a user input data page and a man-machine interaction page, call different modules, and output the calculation results of the amplitude weighting array generation module, the look-up table database for array topology structure design, and the antenna array simulation module as the overall array beam control design scheme; The amplitude weighting array generation module calculates the amplitude weighting array required for corresponding beamforming according to the amplitude weighting matrix of the user input data by using the non-separable Chebyshev matrix and transmits it to the software module; The look-up table database for array topology structure design looks up the high-dimensional matrix data obtained by linearly fitting the relationship between the array topology structure and the main lobe width and main-to-side lobe gain of the array beam according to the user's requirement for the array scale, and obtains the array topology structure design scheme and transmits it to the software module; The antenna array simulation module is used to simulate and verify the array topology structure design scheme, obtain the phase weighting matrix in the design scheme through the beam pointing control calculation relationship of the phased array, output the antenna far-field pattern required for the corresponding scheme, and transmit it to the software module.

2. The phased array radar far-field beamforming system according to claim 1, characterized in that, The software module includes a man-machine interface sub-module, an input data sub-module, a program call sub-module, and a data output sub-module connected in sequence; The man-machine interface sub-module is used for man-machine interaction; The input data sub-module is used to receive the expected index data of the antenna array input by the user, where the expected index data of the antenna array includes the expected main lobe width, main lobe gain, side lobe gain, and array scale of the array; The program call sub-module is used to design the overall array beam control scheme for the amplitude weighting array generation module, the look-up table database for array topology structure design, and the antenna array simulation module; The data output sub-module is used to output the overall array beam control design scheme.

3. The phased array radar far-field beamforming system according to claim 1, characterized in that, The amplitude weighting array generation module, the look-up table database for array topology structure design, and the antenna array simulation module are all bidirectionally communicatively connected to the program call sub-module.

4. A phased array radar far-field beamforming system according to claim 1, characterized in that, The antenna array simulation program includes a beam pointing control sub-module, a phase weighting array generation sub-module, an array beam simulation sub-module, and a simulation parameter output sub-module connected in sequence; The beam pointing control sub-module is used to calculate the beam pointing control relationship of the phased array; The phase weighting array generation sub-module is used to calculate the phase distribution relationship, and combines the beam pointing control relationship of the phased array to calculate the phase weighting matrix of the array topology structure design scheme; The array beam simulation sub-module is used to calculate the antenna far-field pattern required for the array topology structure design scheme; The simulation parameter output sub-module is used to transmit the phase weighting matrix and the antenna far-field pattern to the software module.

5. A far - field beamforming method for a phased array radar, applied to a far - field beamforming system of a phased array radar according to any one of claims 1 - 4, characterized in that, Including: Step 1: The user inputs the expected array scale, main lobe width, main lobe gain, and side lobe gain through the man-machine interface sub-module and the data input sub-module; Step 2: Call the amplitude weighting array generation module through the program call sub-module. According to the amplitude weighting matrix of the user input data, calculate the amplitude weighting array required for the corresponding beamforming using the non-separable Chebyshev matrix and transmit it to the software module; Step 3: Call the array topology design look-up database through the program call sub-module. According to the expected array scale, main and side lobe gains, and main lobe width, obtain the element spacing parameter of the array by querying the high-dimensional matrix obtained by fitting the linear relationship between the array topology and the corresponding parameters, and obtain the array topology design scheme and transmit it to the software module; Step 4: Call the antenna array simulation module through the program call sub-module to simulate the obtained amplitude weighting array and the array topology design scheme; Step 5: Obtain the phase weighting matrix in the design scheme through the beam pointing control sub-module, phase weighting array generation sub-module, and array beam simulation sub-module, output the corresponding required antenna far-field pattern and transmit it to the software module through the simulation parameter output sub-module; Step 6: The software module takes the received amplitude weighting matrix, phase weighting matrix, and array topology design scheme as the overall array beam regulation design scheme and outputs it through the data output sub-module.

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