Method and system for aligning electric axis and mechanical axis of large-scale broadband phased-array antenna

Abstract

The invention discloses a large-scale broadband 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: a frequency slicing stage: equally dividing the working frequency of the phased-array antenna into n slice frequency points within an instantaneous bandwidth range; in a beam scanning and data acquisition stage, acquiring an amplitude data set of each slice frequency point; an electric axis position extraction stage: respectively extracting an electric axis position from the amplitude data set of each slice frequency point to obtain an electric axis position set; in the electric axis center calculation stage, a least square method is adopted to find out an electric axis position concentration area, and the area serves as the electric axis center position of the phased-array antenna in the instantaneous bandwidth; and an electric axis and mechanical axis alignment stage: setting a beam scanning instruction according to the central position of the electric axis, so that the electric axis of the phased-array antenna is aligned with the mechanical axis. The method is not limited by the influence of manual and mechanical adjustment precision, and the electric shaft and mechanical shaft alignment precision at the 0.01 degree level can be achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of phased array antenna, and particularly relates to a large wideband phased array antenna electric axis and mechanical axis alignment method and system. BACKGROUND

[0002] With the rapid development and application of phased array antenna technology, the instantaneous bandwidth requirement is higher and higher, the array size is larger and larger, and the large wideband phased array antenna is applied more and more widely.

[0003] In the debugging and testing of large wideband phased array antenna and engineering application, the following prominent shortcomings are presented: The machining error, flatness precision of large structural parts, array installation error, amplitude and phase difference of the feed network, etc., will all cause the inconsistency between the electric axis and the mechanical axis of the phased array; The large array brings narrow beam width, and it is difficult to align the electric axis and the mechanical axis of the beam, and the gain loss caused by beam alignment is more obvious.

[0004] Under the condition of large instantaneous bandwidth and large array, the difference between high-frequency and low-frequency beam width causes poor in-band flatness in the frequency domain and coverage space, which brings great inconvenience to the demodulation of the back-end signal of the large wideband phased array antenna; At present, the alignment method of the electric axis and the mechanical axis of the large array beam mostly adopts manual fine adjustment, which has certain blindness, and it is difficult to align the electric axis and the mechanical axis of the array, and the efficiency is low, the difficulty is great, and the effect is poor.

[0005] Taking the working frequency of 10.7-12.7GHz, the instantaneous bandwidth of 2GHz, and the array size of 80*80 as an example, the normalized normal pattern is as shown in Figure 2 In the instantaneous bandwidth range, the gain difference curve of high-frequency (12.7GHz) and low-frequency (10.7GHz) with the change of the elevation angle theta is as shown in Figure 3 It can be seen from Figure 3 When the electric axis and the mechanical axis of the beam are deviated by 0.8°, the gain deviation of high-frequency (12.7GHz) and low-frequency (10.7GHz) reaches 5dB, which is not allowed in the use of high-performance phased array. SUMMARY

[0006] The present application aims to overcome the shortcomings of the prior art and provide a large wideband phased array antenna electric axis and mechanical axis alignment method and system.

[0007] The purpose of the present application is achieved by the following technical scheme: the present application provides a large wideband phased array antenna electric axis and mechanical axis alignment method, comprising 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 collection stage, the phased array antenna is polled to perform beam scanning in a preset beam width range with a mechanical axis as the center and according to a preset azimuth step delta_phi and an elevation step delta_theta, and signal amplitude values of each beam scanning point are recorded to obtain an amplitude data set of each slice frequency point; In the electric axis position extraction stage, maximum amplitude values are found from the amplitude data set of each slice frequency point, and beam control angles corresponding to the maximum amplitude values are recorded to determine the beam control angles as electric axis positions of the slice frequency points, and an electric axis position set is obtained; In the electric axis center calculation stage, all electric axis positions are compared, and a least square method is used to find a central region of the electric axis position set as an electric axis center position of the phased array antenna in the instantaneous bandwidth; In the electric axis and mechanical axis alignment stage, the beam scanning instruction is set by taking negative values of the horizontal and vertical coordinates of the electric axis center position, so that the electric axis of the phased array antenna is aligned with the mechanical axis.

[0008] Preferably, the preset beam width range is 3dB.

[0009] Preferably, the amplitude data set is collected in a microwave darkroom environment.

[0010] The second aspect of the present application provides: a large wideband phased array antenna electric axis and mechanical axis alignment system for implementing any of the large wideband phased array antenna electric axis and mechanical axis alignment methods, comprising: A frequency slicing module is configured to divide the working frequency of the phased array antenna into n slice frequency points in the instantaneous bandwidth range; A beam scanning and data collection module is configured to poll the phased array antenna to perform beam scanning in a preset beam width range with a mechanical axis as the center and according to a preset azimuth step delta_phi and an elevation step delta_theta at each slice frequency point, and record signal amplitude values of each beam scanning point to obtain an amplitude data set of each slice frequency point; An electric axis position extraction module is configured to find maximum amplitude values from the amplitude data set of each slice frequency point, record beam control angles corresponding to the maximum amplitude values, determine the beam control angles as electric axis positions of the slice frequency points, and obtain an electric axis position set; An electric axis center calculation module is configured to compare all electric axis positions, and use a least square method to find a central region of the electric axis position set as an electric axis center position of the phased array antenna in the instantaneous bandwidth; An electric axis and mechanical axis alignment module is configured to set the beam scanning instruction by taking negative values of the horizontal and vertical coordinates of the electric axis center position, so that the electric axis of the phased array antenna is aligned with the mechanical axis.

[0011] The third aspect of the present application provides a computer readable storage medium, the computer readable storage medium stores computer executable instructions, when the computer executable instructions are loaded and executed by a processor, the method for aligning the electrical axis and the mechanical axis of a large broadband phased array antenna is realized.

[0012] The beneficial effects of the present application are: 1) High precision: not limited by the precision of manual mechanical adjustment, using the phased array fine beam scanning amplitude maximum value method, the electrical axis and mechanical axis alignment accuracy can reach 0.01° level.

[0013] 2) High efficiency: combined with the phased array fine beam scanning amplitude maximum value method, using the phased array microsecond level beam control capability, the electrical axis and mechanical axis alignment can be completed in minutes. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 The method flowchart of the present application; Figure 2 The large broadband phased array antenna normal local normalized pattern; Figure 3 The 12.7-10.7GHz gain difference curve with angle change gain. DETAILED DESCRIPTION

[0015] The technical solutions of the present application will be described below in conjunction with the embodiments, obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0016] Referring to Figures 1-3 The first aspect of the present application provides a method for aligning the electrical axis and the mechanical axis of a large broadband phased array antenna, comprising the following steps: In the frequency slicing stage, the operating frequency of the phased array antenna is equally divided into n slicing frequency points within the instantaneous bandwidth range; In the beam scanning and data acquisition stage, the phased array antenna is controlled to perform beam scanning in the preset beam width range with the mechanical axis as the center, according to the preset azimuth step delta_phi and the preset pitch step delta_theta, at each slicing frequency point, and the signal amplitude value of each beam scanning point is recorded to obtain the amplitude data set of each slicing frequency point; In the electrical axis position extraction stage, 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, the beam control angle is determined as the electrical axis position of the slicing frequency point, and the electrical axis position set is obtained. The electric axis center calculation stage compares all electric axis positions, and finds a concentrated area of electric axis positions as the electric axis center position of the phased array antenna in the instantaneous bandwidth by using the least square method. The electric axis and mechanical axis alignment stage sets a beam scanning instruction by taking the negative values of the horizontal and vertical coordinates of the electric axis center position, so that the electric axis and the mechanical axis of the phased array antenna are aligned.

[0017] In the embodiment, the large size and wide bandwidth of the large wideband phased array antenna are relative concepts in practical applications, and the following references are given by the present application: large size: beam width less than 2°; wide bandwidth: 5% instantaneous bandwidth. The present application combines the frequency slicing method with the maximum beam refinement scanning amplitude method in the preset beam width range (3dB) to complete the alignment of the electric axis and the mechanical axis of the large wideband phased array antenna. In the microwave darkroom, the phased array beam scanning flexibility and the fine beam control stepping characteristics are used to slice the phased array antenna operating frequency in the instantaneous bandwidth range according to n (f1, f2, f3…fn), and each slice frequency point is polled to control the phased array beam with the mechanical axis (0, 0) as the center, and in the 3dB beam range, the azimuth step delta_phi and the elevation step delta_theta are scanned one by one. Then, the amplitude value groups of each beam scanning point at each slice frequency (f1, f2, f3…fn) are recorded, and the maximum amplitude value in the beam scanning amplitude value at each slice frequency corresponds to the beam control angle, that is, the electric axis position (N1, N2, N3…Nn) at the slice frequency. By comparing all frequency electric axis positions (N1, N2, N3…Nn), the least square method is used to find the concentrated area N(phi0, theta0) of the electric axis positions, as the electric axis center N(phi0, theta0) of the large phased array in the instantaneous bandwidth. By setting the beam scanning N'(-phi0, -theta0) by the phased array beam control, the electric axis and the mechanical axis can be aligned. The electric axis center position is N(phi0, theta0), and the set beam scanning instruction is N'(-phi0, -theta0), which is opposite, so as to set the beam position to zero by beam scanning, thereby realizing the alignment.

[0018] In some embodiments, the preset beam width range is 3dB.

[0019] In some embodiments, the amplitude data set is collected in the microwave darkroom environment.

[0020] The second aspect of the present application provides: a large wideband phased array antenna electric axis and mechanical axis alignment system for realizing any one of the above large wideband phased array antenna electric axis and mechanical axis alignment methods, comprising: A frequency slicing module is configured to divide the operating frequency of the phased array antenna into n frequency slice points in the instantaneous bandwidth range. A beam scanning and data collection module is configured to poll the phased array antenna to perform beam scanning in a preset beam width range with a mechanical axis as the center, according to a preset azimuth step delta_phi and an elevation step delta_theta, and record the signal amplitude value of each beam scanning point, to obtain an amplitude data set of each frequency slice point. An electrical axis position extraction module is configured to find the maximum amplitude value from the amplitude data set of each frequency slice point, and record the beam control angle corresponding to the maximum amplitude value, to determine the beam control angle as the electrical axis position of the frequency slice point, and obtain an electrical axis position set. An electrical axis center calculation module is configured to compare all electrical axis positions, and find the regional electrical axis position set by using the least square method, as the electrical axis center position of the phased array antenna in the instantaneous bandwidth range. An electrical axis and mechanical axis alignment module is configured to set the beam scanning instruction by taking the horizontal and vertical coordinates of the electrical axis center position as negative values, to align the electrical axis and the mechanical axis of the phased array antenna.

[0021] The third aspect of the present application provides a computer readable storage medium, wherein the computer readable storage medium stores computer executable instructions, and the computer executable instructions are loaded and executed by a processor to implement any of the above-mentioned large wideband phased array antenna electrical axis and mechanical axis alignment methods.

[0022] The above description is only preferred embodiments of the present application, and it should be understood that the present application is not limited to the forms disclosed herein, and should not be considered as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concepts described herein by the above-mentioned teaching or related art or knowledge. Any modification and change made by those skilled in the art without departing from the spirit and scope of the present application shall be within the protection scope of the appended claims of the present application.

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 controlled to perform beam scanning within a preset beam width range with the mechanical axis as the center 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 horizontal and vertical coordinates of the electric axis center position are set to negative values to set the beam scanning instruction, 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 3 dB.

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 comprises: a frequency slicing module, which is used to equally divide the operating frequency of the phased array antenna into n slicing frequency points within a transient bandwidth range; a beam scanning and data collection module, which is used to control the phased array antenna to perform beam scanning within a preset beam width range with the mechanical axis as the center 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; an electric axis position extraction module, which is used 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; an electric axis center calculation module, which is used 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; an electric axis and mechanical axis alignment module, which is used to set the beam scanning instruction by taking the horizontal and vertical coordinates of the electric axis center position to negative values, 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, and when the computer executable instructions are loaded and executed by the processor, 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.

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