A method and system for aligning the electrical and mechanical axes of a large broadband phased array antenna.

Abstract

The application discloses a large wideband phased array antenna electric axis and mechanical axis alignment method and system, and belongs to the technical field of phased array antennas. The method comprises the following steps: in the frequency slicing stage, the working frequency of the phased array antenna is equally divided into n slicing frequency points in the instantaneous bandwidth range; in the beam scanning and data acquisition stage, the amplitude data set of each slicing frequency point is collected; in the electric axis position extraction stage, the electric axis position is extracted from the amplitude data set of each slicing frequency point, and an electric axis position set is obtained; in the electric axis center calculation stage, the least square method is used to find the regional electric axis position set, which is used as the electric axis center position of the phased array antenna in the instantaneous bandwidth; and in the electric axis and mechanical axis alignment stage, the beam scanning instruction is set according to the electric axis center position, so that the electric axis and the mechanical axis of the phased array antenna are aligned. The application is not affected by the precision of artificial mechanical adjustment, and can achieve the alignment precision of the electric axis and the mechanical axis at the level of 0.01 degrees.

Description

Technical Field

[0001] This invention relates to the field of phased array antenna technology, and in particular to a method and system for aligning the electrical axis and mechanical axis of a large broadband phased array antenna. Background Technology

[0002] With the rapid development and application of phased array antenna technology, the instantaneous bandwidth requirements are getting higher and higher, the array size is getting larger and larger, and the application of large broadband phased array antennas is becoming more and more widespread.

[0003] In the debugging, testing, and engineering application of large-scale broadband phased array antennas, significant drawbacks are observed:

[0004] Machining errors of large structural components, flatness accuracy, array surface installation errors, and amplitude and phase differences in the power supply network can all cause inconsistencies between the phased array's electrical axis and mechanical axis.

[0005] The large array size results in a narrow beamwidth, making it difficult to align the electrical axis of the beam with the mechanical axis, which leads to more significant gain loss due to beam alignment issues.

[0006] When large instantaneous bandwidth is combined with large arrays, the difference in beamwidth between high frequency and low frequency results in poor in-band flatness in both the frequency domain and the coverage space domain, which brings great inconvenience to the demodulation of signals at the back end of large broadband phased array antennas.

[0007] Currently, most methods for aligning the electrical and mechanical axes of large array beams rely on manual fine-tuning, which is somewhat blind and inefficient, difficult, and ineffective.

[0008] Taking an operating frequency of 10.7-12.7GHz, an instantaneous bandwidth of 2GHz, and an array size of 80*80 as an example, its normalized normal radiation pattern is as follows: Figure 2 As shown. Within the instantaneous bandwidth, the gain difference curves between high frequency (12.7 GHz) and low frequency (10.7 GHz) as a function of pitch angle theta are as follows. Figure 3 As shown, by Figure 3 It is evident that when the beam electrical axis deviates from the mechanical axis by 0.8°, the gain deviation between the high frequency (12.7GHz) and the low frequency (10.7GHz) reaches 5dB, which is unacceptable in the use of high-performance phased arrays. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method and system for aligning the electrical axis and mechanical axis of a large broadband phased array antenna.

[0010] The objective of this invention is achieved through the following technical solution: The first aspect of this invention provides a method for aligning the electrical and mechanical axes of a large broadband phased array antenna, comprising the following steps:

[0011] In the frequency slicing stage, the operating frequency of the phased array antenna is divided into n slice frequency points within the instantaneous bandwidth.

[0012] During the beam scanning and data acquisition phase, the phased array antenna is polled and controlled to perform beam scanning at each slice frequency point, with the mechanical axis as the center, within the preset beam width range, according to the preset azimuth step delta_phi and elevation step delta_theta, and the signal amplitude value of each beam scanning point is recorded to obtain the amplitude dataset of each slice frequency point.

[0013] In the electric axis position extraction stage, the maximum amplitude value is found from the amplitude dataset of each slice frequency point, and the beam control angle corresponding to the maximum amplitude value is recorded. The beam control angle is determined as the electric axis position of the slice frequency point, and the electric axis position set is obtained.

[0014] During the electrical axis center calculation stage, all electrical axis positions are compared, and the least squares method is used to find the concentrated area of ​​electrical axis positions, which is taken as the electrical axis center position of the phased array antenna within the instantaneous bandwidth.

[0015] During the alignment phase between the electrical and mechanical axes, the beam scanning command is set by taking negative values ​​for the horizontal and vertical coordinates of the electrical axis center position, so that the electrical axis of the phased array antenna is aligned with the mechanical axis.

[0016] Preferably, the preset beamwidth range is 3dB.

[0017] Preferably, amplitude datasets are acquired in a microwave anechoic chamber environment.

[0018] A second aspect of the present invention provides: a large broadband phased array antenna electrical axis and mechanical axis alignment system for realizing any of the above-described large broadband phased array antenna electrical axis and mechanical axis alignment methods, comprising:

[0019] The frequency slicing module is used to divide the operating frequency of the phased array antenna into n slice frequency points within the instantaneous bandwidth range;

[0020] The beam scanning and data acquisition module is used to poll and control the phased array antenna to perform beam scanning at each slice frequency point, with the mechanical axis as the center, within a preset beamwidth range, according to preset azimuth step delta_phi and elevation step delta_theta, and record the signal amplitude value of each beam scanning point to obtain the amplitude dataset of each slice frequency point.

[0021] The electrical axis position extraction module is used to find the maximum amplitude value from the amplitude dataset of each slice frequency point, record the beam control angle corresponding to the maximum amplitude value, and determine the beam control angle as the electrical axis position of the slice frequency point to obtain the electrical axis position set.

[0022] The electric axis center calculation module is used to compare all electric axis positions and use the least squares method to find the concentrated area of ​​electric axis positions, which is used as the electric axis center position of the phased array antenna within the instantaneous bandwidth.

[0023] The electrical axis and mechanical axis alignment module is used to set beam scanning commands by taking negative values ​​for the horizontal and vertical coordinates of the electrical axis center position, so that the electrical axis and mechanical axis of the phased array antenna are aligned.

[0024] A third aspect of the present invention provides: a computer-readable storage medium storing computer-executable instructions, wherein when the computer-executable instructions are loaded and executed by a processor, the above-described method for aligning the electrical axis and mechanical axis of a large broadband phased array antenna is implemented.

[0025] The beneficial effects of this invention are:

[0026] 1) High precision: Unaffected by the precision of manual mechanical adjustment, the phased array fine beam scanning amplitude maximum method can achieve an electrical axis and mechanical axis alignment accuracy of 0.01°.

[0027] 2) High efficiency: Combining the phased array fine beam scanning amplitude maximum value method, and utilizing the phased array microsecond-level beam control capability, the alignment of the electric axis and mechanical axis can be completed in minutes. Attached Figure Description

[0028] Figure 1 This is a flowchart of the method of the present invention;

[0029] Figure 2 The normalized normal pattern of a large broadband phased array antenna;

[0030] Figure 3 The graph shows the gain difference as a function of angle in the 12.7-10.7 GHz range. Detailed Implementation

[0031] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] See Figures 1-3 The first aspect of this invention provides: a method for aligning the electrical axis and mechanical axis of a large broadband phased array antenna, comprising the following steps:

[0033] In the frequency slicing stage, the operating frequency of the phased array antenna is divided into n slice frequency points within the instantaneous bandwidth.

[0034] During the beam scanning and data acquisition phase, the phased array antenna is polled and controlled to perform beam scanning at each slice frequency point, with the mechanical axis as the center, within the preset beam width range, according to the preset azimuth step delta_phi and elevation step delta_theta, and the signal amplitude value of each beam scanning point is recorded to obtain the amplitude dataset of each slice frequency point.

[0035] In the electric axis position extraction stage, the maximum amplitude value is found from the amplitude dataset of each slice frequency point, and the beam control angle corresponding to the maximum amplitude value is recorded. The beam control angle is determined as the electric axis position of the slice frequency point, and the electric axis position set is obtained.

[0036] During the electrical axis center calculation stage, all electrical axis positions are compared, and the least squares method is used to find the concentrated area of ​​electrical axis positions, which is taken as the electrical axis center position of the phased array antenna within the instantaneous bandwidth.

[0037] During the alignment phase between the electrical and mechanical axes, the beam scanning command is set by taking negative values ​​for the horizontal and vertical coordinates of the electrical axis center position, so that the electrical axis of the phased array antenna is aligned with the mechanical axis.

[0038] In this embodiment, "large" and "wide" in large broadband phased array antenna are relative concepts in practical applications. The following is a reference provided by this invention: Large: beamwidth less than 2°; Wide: based on 5% instantaneous bandwidth. This invention combines the frequency slicing method with the maximum amplitude method of fine beam scanning within a preset beamwidth range (3dB) to complete the alignment of the electrical and mechanical axes of the large broadband phased array antenna. In a microwave anechoic chamber, utilizing the flexibility of phased array beam scanning and the fine beam control stepping characteristics, the operating frequency of the phased array antenna is sliced ​​into n equal parts (f1, f2, f3...fn) within the instantaneous bandwidth range. At each slice frequency point, the phased array beam is polled and controlled to scan one by one within the 3dB beam range, centered on the mechanical axis (0,0), with azimuth stepping delta_phi and elevation stepping delta_theta.

[0039] Then, record the amplitude value group of each beam scanning point for each slice frequency (f1, f2, f3...fn). The beam control angle corresponding to the maximum amplitude value in the beam scanning amplitude value of each slice frequency is the electrical axis position of that slice frequency (N1, N2, N3...Nn).

[0040] By comparing the electrical axis positions of all frequencies (N1, N2, N3...Nn), the region N(phi0, theta0) where the electrical axis positions are concentrated is found by the least squares method, which is taken as the electrical axis center N(phi0, theta0) of the large phased array within the instantaneous bandwidth.

[0041] By setting the beam scan N'(-phi0, -theta0) using phased array beam control, alignment of the electrical and mechanical axes can be achieved. The center position of the electrical axis is N(phi0, theta0), while the set beam scan command is N'(-phi0, -theta0), with opposite orientations. This is to reset the beam position to zero through beam scanning, thereby achieving alignment.

[0042] In some embodiments, the preset beamwidth range is 3dB.

[0043] In some embodiments, amplitude datasets are acquired in a microwave anechoic chamber environment.

[0044] A second aspect of the present invention provides: a large broadband phased array antenna electrical axis and mechanical axis alignment system for realizing any of the above-described large broadband phased array antenna electrical axis and mechanical axis alignment methods, comprising:

[0045] The frequency slicing module is used to divide the operating frequency of the phased array antenna into n slice frequency points within the instantaneous bandwidth range;

[0046] The beam scanning and data acquisition module is used to poll and control the phased array antenna to perform beam scanning at each slice frequency point, with the mechanical axis as the center, within a preset beamwidth range, according to preset azimuth step delta_phi and elevation step delta_theta, and record the signal amplitude value of each beam scanning point to obtain the amplitude dataset of each slice frequency point.

[0047] The electrical axis position extraction module is used to find the maximum amplitude value from the amplitude dataset of each slice frequency point, record the beam control angle corresponding to the maximum amplitude value, and determine the beam control angle as the electrical axis position of the slice frequency point to obtain the electrical axis position set.

[0048] The electric axis center calculation module is used to compare all electric axis positions and use the least squares method to find the concentrated area of ​​electric axis positions, which is used as the electric axis center position of the phased array antenna within the instantaneous bandwidth.

[0049] The electrical axis and mechanical axis alignment module is used to set beam scanning commands by taking negative values ​​for the horizontal and vertical coordinates of the electrical axis center position, so that the electrical axis and mechanical axis of the phased array antenna are aligned.

[0050] A third aspect of the present invention provides: a computer-readable storage medium storing computer-executable instructions, wherein when the computer-executable instructions are loaded and executed by a processor, the above-described method for aligning the electrical axis and mechanical axis of a large broadband phased array antenna is implemented.

[0051] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A method for aligning the electrical axis with the mechanical axis of a large wideband phased array antenna, characterized by: The method comprises the following steps: a frequency slicing stage, in which the operating frequency of the phased array antenna is equally divided into n slicing frequency points within a transient bandwidth range; a beam scanning and data collection stage, in which the phased array antenna is polled to perform beam scanning within a preset beam width range centered on the mechanical axis and according to preset azimuth step delta_phi and elevation step delta_theta at each slicing frequency point, and the signal amplitude value of each beam scanning point is recorded to obtain an amplitude data set of each slicing frequency point; an electric axis position extraction stage, in which the maximum amplitude value is found from the amplitude data set of each slicing frequency point, and the beam control angle corresponding to the maximum amplitude value is recorded to determine the beam control angle as the electric axis position of the slicing frequency point, thereby obtaining an electric axis position set; an electric axis center calculation stage, in which all electric axis positions are compared, and the central region of the electric axis position set is found by using the least square method as the electric axis center position of the phased array antenna within the transient bandwidth; an electric axis and mechanical axis alignment stage, in which the electric axis center position is N(phi0, theta0), the horizontal and vertical coordinates of the electric axis center position are taken as negative values to set the beam scanning instruction, and the set beam scanning instruction is N'(-phi0, -theta0), so that the electric axis of the phased array antenna is aligned with the mechanical axis.

2. The method of electrical axis and mechanical axis alignment of a large wideband phased array antenna according to claim 1, characterized in that: The preset beam width range is 3dB.

3. The method of claim 1, wherein: The amplitude data set is collected in a microwave darkroom environment.

4. A large wideband phased array antenna electrical axis and mechanical axis alignment system, characterized by: The method for aligning the electric axis and the mechanical axis of a large wideband phased array antenna according to any one of claims 1-3 is implemented by using a computer readable storage medium, and the computer readable storage medium stores computer executable instructions. The frequency slicing module is configured to equally divide the operating frequency of the phased array antenna into n slicing frequency points within a transient bandwidth range. The beam scanning and data collection module is configured to poll the phased array antenna to perform beam scanning within a preset beam width range centered on the mechanical axis and according to preset azimuth step delta_phi and elevation step delta_theta at each slicing frequency point, and record the signal amplitude value of each beam scanning point to obtain an amplitude data set of each slicing frequency point. The electric axis position extraction module is configured to find the maximum amplitude value from the amplitude data set of each slicing frequency point, record the beam control angle corresponding to the maximum amplitude value, determine the beam control angle as the electric axis position of the slicing frequency point, and obtain an electric axis position set. The electric axis center calculation module is configured to compare all electric axis positions, and find the central region of the electric axis position set by using the least square method as the electric axis center position of the phased array antenna within the transient bandwidth. The electric axis and mechanical axis alignment module is configured to take the horizontal and vertical coordinates of the electric axis center position as negative values to set the beam scanning instruction, so that the electric axis of the phased array antenna is aligned with the mechanical axis.

5. A computer-readable storage medium, characterized in that: The computer readable storage medium stores computer executable instructions, which are loaded and executed by a processor to implement the method for aligning the electric axis and the mechanical axis of a large wideband phased array antenna according to any one of claims 1-3.

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