A method for determining the phase center of the radio frequency front end of a phased array antenna

Abstract

The present invention relates to the field of antenna measurement technology, and proposes a method for determining the phase center of the radio frequency front end of a phased array antenna. The method comprises: S1: installing a phased array antenna and adjusting the geometric center position of the array surface of the phased array antenna; S2: obtaining the phase center offset and phase pattern of the phased array antenna; S3: if the phase pattern is not a straight line, executing S4, and if the phase pattern is a straight line, executing S9; S4: comparing the phase pattern with each reference image in the image library to obtain multiple similarities; S5: selecting the reference image corresponding to the maximum value among the multiple similarities; S6: determining the moving direction of the turntable manipulator according to the selected reference image; S7: moving the turntable manipulator according to the moving direction and the phase center offset; S8: returning to S2; S9: outputting the phase center of the phased array antenna. The method can realize efficient and accurate determination of the phase center.

Description

Technical Field

[0001] The present invention relates to the field of antenna measurement technology, and in particular to a method for measuring the phase center of a radio frequency front end of a phased array antenna. Background Art

[0002] Phased array antennas are widely used in modern radar, communication and electronic countermeasure systems. The phase difference between the array elements directly affects the formation of the antenna beam and the accuracy of the radiation direction. Determining the precise position of the antenna phase center is a key link in realizing the directional control of the antenna beam, especially in the case of multi-directional phase calibration. The ability to accurately determine and calibrate the phase center of the antenna helps to improve the antenna performance. At present, the methods for determining the phase center of the phased array antenna are mainly divided into three categories. The first category is to analyze and solve the directional pattern function of the antenna far field. This method is complex to calculate and is even less operable when there are processing errors and assembly errors in the phased array antenna. The second method is to mark it through the antenna phase center marking plug-in of the commercial electromagnetic simulation software. The phase center calculation plug-in of the commercial electromagnetic simulation software (such as CST software) can analyze the phase center of the antenna based on the model established by the scientific researchers in the software, but its reliability needs to be further verified in engineering applications. The third method is to analyze the phase pattern of the phased array antenna and mark the phase center by combining experiments and calculations. Commonly used methods for determining the phase center of the phased array antenna include: key point method, simulated annealing algorithm and phase gradient method. Among them, the key point method only focuses on a few key points without constraining the phase of the entire angular region of interest to be the flattest, and the result is inaccurate; the accuracy of the simulated annealing algorithm depends on the selection of search points, and its iterative calculation process is cumbersome and complicated; the approximate value of the phase gradient and the error accumulation of the approximate fitting have a greater impact on the accuracy.

[0003] In view of this, this application is hereby filed. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the existing method for determining the phase center of a phased array antenna is complex to operate and has low precision.

[0005] In order to solve the above technical problems, the present invention is implemented by the following technical solutions:

[0006] A method for determining the phase center of a phased array antenna radio frequency front end is proposed, comprising the following steps: S1: installing the phased array antenna on a vertical turntable of a turntable manipulator, adjusting the geometric center of the opening plane of the horn antenna and the geometric center of the array surface of the phased array antenna to the rotation axis of the vertical turntable, and adjusting the geometric center of the array surface of the phased array antenna to the rotation axis of the horizontal turntable of the turntable manipulator; S2: obtaining the phase center offset of the phased array antenna and the phase pattern of the sum beam of the phased array antenna; S3: if the If the phase pattern is not a straight line, execute S4; if the phase pattern is a straight line, execute S9; S4: compare the phase pattern with each reference pattern in the library to obtain multiple similarities; S5: select the reference pattern corresponding to the maximum value of the multiple similarities; S6: determine the moving direction of the turntable manipulator according to the selected reference pattern; S7: move the turntable manipulator according to the moving direction and the phase center offset; S8: return to S2; S9: output the phase center of the phased array antenna.

[0007] Furthermore, before S2, the following steps are also included: performing beam calibration on the phased array antenna in the direction of the pitch angle by adjusting the vertical turntable; and performing beam calibration on the phased array antenna in the direction of the azimuth angle by adjusting the horizontal turntable.

[0008] Furthermore, before S2, the following step is also included: performing equal phase leveling on the phased array antenna.

[0009] Furthermore, the phase-leveling of the phased array antenna includes the following steps: A1: obtaining a first phase average value of the first-row phase channel of the phased array antenna, obtaining a second phase average value of the last-row phase channel of the phased array antenna, and obtaining a first difference between the first phase average value and the second phase average value; A2: if the first difference is ≥10°, executing A3; if the first difference is <10°, executing A5; A3: obtaining an azimuth axis adjustment angle according to a calculation model and the first difference; the expression of the calculation model is: adjustment angle = ; A4: Adjust the horizontal turntable according to the azimuth axis adjustment angle, and return to A1; A5: Obtain the third phase average value of the first phase channel of the phased array antenna, obtain the fourth phase average value of the last phase channel of the phased array antenna, and obtain the second difference between the third phase average value and the fourth phase average value; A6: If the second difference is ≥10°, execute A7; if the second difference is <10°, complete equal phase leveling; A7: Obtain the pitch axis adjustment angle according to the calculation model and the second difference; A8: Adjust the vertical turntable according to the pitch axis adjustment angle, and return to A5.

[0010] Furthermore, the method for determining the phase center of the RF front end of the phased array antenna also includes the following steps: S10: respectively obtain a first phase pattern with a beam of -30°, a second phase pattern with a beam of 0°, and a third phase pattern with a beam of 30°; S11: if at least one of the first phase pattern, the second phase pattern, and the third phase pattern is not a straight line, execute S12; if the first phase pattern, the second phase pattern, and the third phase pattern are all straight lines, execute S13; S12: move the turntable manipulator according to the methods described in S4 to S7, and return to S2; S13: output the phase center of the phased array antenna.

[0011] Furthermore, the library includes: a first reference diagram, which is used to indicate that in a plane rectangular coordinate system with the geometric center of the array surface as the origin, the phase center of the phased array antenna is located on the y-axis and above the geometric center of the array surface; a second reference diagram, which is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located on the y-axis and below the geometric center of the array surface; a third reference diagram, which is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located on the x-axis and to the left of the geometric center of the array surface; a fourth reference diagram, which is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located on the x-axis and to the left of the geometric center of the array surface; In the rectangular coordinate system, the phase center of the phased array antenna is located on the x-axis and to the right of the geometric center of the array surface; the fifth reference figure is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located in the first quadrant; the sixth reference figure is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located in the second quadrant; the seventh reference figure is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located in the third quadrant; the eighth reference figure is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located in the fourth quadrant.

[0012] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0013] 1. With the advantage of the turntable manipulator's flexible movement in the front and back, horizontal, vertical, and left and right directions, the moving reference point method is used to repeatedly obtain and adjust the position of the phase center, thereby achieving efficient and accurate measurement of the phase center. Specifically, on the one hand, considering that the phase center of the phased array antenna is different on each section, this method adjusts the position of the geometric center of the array surface of the phased array antenna by moving the turntable manipulator, and transfers the measurement of the phase center to the section with φ=0° and the section with φ=90°, so that the phase center deviation in spherical coordinates can be regarded as the offset of the phase center on the z-axis, thereby simplifying the subsequent operation process of moving the turntable manipulator according to the phase center deviation; on the other hand, based on the phase pattern and phase center offset obtained for the first time, multiple reference patterns are provided to characterize the various offset conditions of the phase center, and the current reference point of the segment is judged to be the phase center by comparing the phase pattern. According to the comparison results, the phase center offset, the phase pattern, the phase pattern comparison, and the moving turntable manipulator are repeatedly executed to optimize the measurement results of the phase center. The method performs simple steps repeatedly and can achieve efficient and accurate determination of the phase center without complicated calculations.

[0014] 2. By adjusting the turntable manipulator, the phased array antenna was beam calibrated in the pitch angle direction and azimuth angle, and the phased array antenna was leveled, which reduced the installation error and system error of the phased array antenna, thereby improving the accuracy of measuring the phase center.

[0015] 3. The phase center stability test was performed by obtaining the phase radiation diagrams with beams of -30°, 0° and 30°, and adjustments were made based on the test results to further improve the accuracy of the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A flow chart of a method for determining a phase center of a phased array antenna RF front end provided in Embodiment 1 of the present invention;

[0018] Figure 2 A diagram showing the positional relationship between the phased array antenna, the horn antenna and the turntable manipulator provided in Example 1 of the present invention;

[0019] Figure 3A schematic diagram of eight phase center deviation situations provided in Example 1 of the present invention;

[0020] Figure 4 Schematic diagram of eight movement modes of the turntable manipulator provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0022] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is apparent to one of ordinary skill in the art that these specific details are not necessarily employed to practice the present invention. In other embodiments, in order to avoid obscuring the present invention, well-known structures, circuits, materials, or methods are not specifically described.

[0023] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment," "an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. In addition, it will be appreciated by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0024] In the description of the present invention, the directions or positional relationships indicated by terms such as “front”, “rear”, “left”, “right”, “up”, “down”, “vertical”, “horizontal”, “high”, “low”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the scope of protection of the present invention.

[0025] Embodiment 1: A method for measuring the phase center of a phased array antenna RF front end is provided. Before systematically describing the specific execution steps of the method, the principle of phase center measurement is first explained.

[0026] Principle 1: Measuring the phase center means measuring the phase center on a certain cross section of the antenna.

[0027] For any antenna, a certain component of its far-field radiation field can be expressed in the spherical coordinate system by the amplitude pattern function and the phase pattern function, and the expression is: (1); In formula (1), E represents the radiation field component of the antenna park, represents the reference polarization vector, is the amplitude pattern function, represents the off-axis angle, represents the rotation angle, j represents an imaginary number, is the phase pattern function, k represents the wave number, , represents wavelength and r represents distance.

[0028] The phase center is defined as: At a given frequency, there is a reference point on or near the antenna that makes the phase pattern function If equal to a constant, the reference point is called the phase center of the antenna. Most antennas do not have a phase pattern function that There is a phase center equal to a constant, but there is a reference point that keeps the phase of the field relatively constant within a certain range of the main lobe, which is called the "apparent phase center". In addition, different cross-sections of some antennas may have different phase centers, and these phase centers may not coincide, so measuring the phase center actually means measuring the phase center on a certain cross-section of the antenna.

[0029] Principle 2: In the spherical coordinate system, the phase center is found by changing the x offset, y offset, and z offset of the reference point to minimize the phase change rate.

[0030] The phase center of the phased array antenna actually measured may deviate from the geometric center of the phased array antenna. The far field expression with the deviated phase center as the reference point is: (2); In formula (2), is the deviation between the phase center of the phased array and the geometric center of the phased array, is a small vector, (3); In formula (3), Indicates the offset of the phase center in the x-axis direction, represents the x-axis direction vector, Indicates the offset of the phase center in the y-axis direction, represents the y-axis direction vector, Indicates the offset of the phase center in the z-axis direction, represents the z-axis direction vector. The deviation between the phase center of the phased array and the geometric center of the phased array can also be expressed as (4); In formula (4), is the deviation between the phase center of the phased array and the geometric center of the phased array, is a unit vector. Therefore, the expression of the phase center pattern function with the offset phase center as the reference point is (5); In formula (5), is the phase center pattern function with the offset phase center as the reference point, and is the phase pattern function when the phase center coincides with the geometric center of the array. Therefore, it can be concluded from equation (5) that in the spherical coordinate system, the phase center can be found by changing the x offset, y offset, and z offset of the reference point to minimize the phase change rate.

[0031] Principle 3: Verify the phase center by verifying whether the phase distribution of the radiation field within the main lobe is flat.

[0032] In practical applications, verifying whether a point is the phase center of the antenna is usually verified from the definition of the apparent phase center. Specifically, the phase pattern of the phased array antenna in the far field is measured with a certain point as the reference point to verify whether the reference point makes the phase distribution of the radiation field in the main lobe range the flattest. If so, the reference point is considered to be the phase center of the antenna.

[0033] Based on the above principles, this embodiment proposes a method for determining the phase center of the RF front end of a phased array antenna. By taking advantage of the turntable manipulator's ability to quickly and accurately move forward and backward, horizontally, and left and right, the moving reference point method is selected to verify whether the reference point is the phase center.

[0034] like Figure 1 As shown, the method comprises the following steps:

[0035] Step 1: Install the phased array antenna and adjust the geometric center position of the phased array antenna.

[0036] Specifically, the phased array antenna is installed on the vertical turntable of the turntable manipulator, the geometric center of the opening plane of the horn antenna and the geometric center of the array of the phased array antenna are adjusted to the rotation axis of the vertical turntable, and the geometric center of the array of the phased array antenna is adjusted to the rotation axis of the horizontal turntable of the turntable manipulator. After the installation is completed, the positional relationship between the phased array antenna, the horn antenna and the turntable manipulator is as follows: Figure 2 shown.

[0037] The following is an explanation of step 1 above:

[0038] When the phased array antenna is an ideal spherical wave source, the phase pattern function is a constant. The actual phased array antenna is usually not an ideal spherical wave source, but it can be considered that the phase pattern function within a certain range of the main lobe on a certain cross section is Equal to a constant to determine the apparent phase center.

[0039] Therefore, it is assumed that the phase pattern of the measured phased array antenna is considered to be The cross section and The above formula (5) can be simplified to (6); In formula (6), when hour, Equivalent to ,when hour, Equivalent to According to formula (6), it can be concluded that on a certain cross section The relationship between the phase center offset (the difference between the far-field phase in a certain direction and the far-field phase in the direction of maximum radiation) is: (7); In formula (7), Indicates the maximum radiation direction. Applying the least square method to solve equation (7), the phase center offset can be obtained. Combined with the above principle 2, it can be seen that the phase center offset can be regarded as Measured on the cross section Value and Measured on the cross section Value. Time Surface Selection (8) Higher accuracy can be achieved.

[0040] In this step, the phased array antenna is installed on the vertical turntable of the turntable manipulator by taking advantage of the flexible movement of the turntable manipulator, and the vertical turntable and horizontal turntable of the turntable manipulator are adjusted so that the geometric center of the opening plane of the horn antenna and the geometric center of the array surface of the phased array antenna are both located on the rotation axis of the vertical turntable, and the geometric center of the array surface of the phased array antenna is located on the rotation axis of the horizontal turntable of the turntable manipulator, thereby realizing the transfer of the measured phase center to The cross section and Carried out on cross section.

[0041] Step 2: Perform beamforming phase calibration on the phased array antenna.

[0042] The specific method is: by adjusting the vertical turntable, the phased array antenna is calibrated in the pitch direction. By adjusting the horizontal turntable, the phased array antenna is calibrated in the azimuth direction, thereby reducing the installation error and system error of the phased array antenna and improving the measurement accuracy.

[0043] Step 3: Perform equal phase leveling on the phased array antenna.

[0044] The specific steps include:

[0045] Step 3.1: Obtain a first phase average value of a first-row phase channel of the phased array antenna, obtain a second phase average value of a last-row phase channel of the phased array antenna, and obtain a first difference between the first phase average value and the second phase average value.

[0046] Step 3.2: If the first difference is ≥10°, execute step 3.3; if the first difference is <10°, execute step 3.5.

[0047] Step 3.3: Calculate the azimuth axis adjustment angle according to the calculation model and the first difference value.

[0048] The expression of the calculation model is: Adjustment angle = (8).

[0049] Step 3.4: Adjust the horizontal turntable according to the azimuth axis adjustment angle and return to step 3.1.

[0050] Step 3.5: Obtain a third phase average value of the first phase channel of the phased array antenna, obtain a fourth phase average value of the last phase channel of the phased array antenna, and obtain a second difference between the third phase average value and the fourth phase average value.

[0051] Step 3.6: If the second difference is ≥10°, execute A7; if the second difference is <10°, equal phase leveling is completed.

[0052] Step 3.7: Calculate the pitch axis adjustment angle according to equation (8) and the second difference.

[0053] Step 3.8: Adjust the vertical turntable according to the pitch axis adjustment angle and return to step 3.5.

[0054] At this point, the array isophase leveling is completed, which can further reduce the installation error and system error of the phased array antenna and further improve the measurement accuracy. By performing beam method phase calibration and isophase leveling on the phased array antenna, the reference point can be brought closer to the phase center.

[0055] Step 4: Obtain the phase center offset of the phased array antenna and the phase pattern of the sum beam of the phased array antenna.

[0056] Step 5: Determine whether the phase pattern is a straight line.

[0057] If the phase pattern is not a straight line, execute step 6; if the phase pattern is a straight line, execute step 10.

[0058] Step 6: Compare the phase pattern with each reference image in the image library to obtain multiple similarities.

[0059] In this embodiment, the gallery stores Figure 3For the convenience of explanation, the eight reference images are named as the first reference image, the second reference image, the third reference image, the fourth reference image, the fifth reference image, the sixth reference image, the seventh reference image and the eighth reference image. Among them, the first reference diagram is used to indicate that in a plane rectangular coordinate system with the geometric center of the array surface as the origin, the phase center of the phased array antenna is located on the y-axis and above the geometric center of the array surface; the second reference diagram is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located on the y-axis and below the geometric center of the array surface; the third reference diagram is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located on the x-axis and to the left of the geometric center of the array surface; the fourth reference diagram is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located on the x-axis and to the right of the geometric center of the array surface; the fifth reference diagram is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located in the first quadrant; the sixth reference diagram is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located in the second quadrant; the seventh reference diagram is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located in the third quadrant; the eighth reference diagram is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located in the fourth quadrant.

[0060] The above 8 reference images respectively show 8 possible situations when the phase center is offset. By calculating the similarity between the phase pattern and each reference image, it can be used to determine the possibility of the above 8 offset situations of the phase center.

[0061] Step 7: Select the reference image corresponding to the maximum value among multiple similarities.

[0062] The phase center offset is determined by similarity comparison.

[0063] Step 8: Determine the moving direction of the turntable manipulator based on the selected reference image.

[0064] According to the above principle 1, in an ideal state, the geometric center of the array of the phased array antenna should coincide with the phase center, so that the phase pattern function is a constant; but in actual conditions, the phase center is usually offset. When the phase center is offset, in order to make the phase change rate of the radiation field within the main lobe range on a certain cross section relatively constant, it is necessary to adjust the position of the geometric center of the array of the phased array antenna so that the geometric center of the array is close to the phase center.

[0065] For example, when the phase center offset determined in step 7 is Figure 3 In the case shown in the first reference figure, it means that the phase center is shifted above the geometric center of the array surface, and the geometric center of the array surface of the phased array antenna should also move upward. According to the mark "2" in the first reference figure, it corresponds to Figure 4In the figure, the mark "2" is located on the y-axis and above the origin O, that is, the moving direction of the geometric center of the array. In addition, in this embodiment, since the phased array antenna is installed on the vertical turntable of the turntable manipulator, the moving geometric center of the array is achieved by moving the turntable manipulator.

[0066] Step 9: Move the turntable manipulator according to the moving direction and the phase center offset.

[0067] Step 8 determines the moving direction of the turntable manipulator. Furthermore, the movement amplitude is determined according to the phase center offset calculated in step 4. After the movement, it is necessary to re-acquire the phase center offset of the phased array antenna and the phase pattern of the sum beam of the phased array antenna, and re-determine the phase center according to the methods provided in steps 5 to 9 above. If the phase pattern obtained after multiple operations is a straight line, it means that the phase change rate of the radiation field within the lobe range is relatively constant, then the phase center determination is completed, and step 10 is executed.

[0068] Step 10: Output the phase center of the phased array antenna.

[0069] According to the above steps 1 to 10, the phase center determination of the phased array antenna can usually be completed within 3 times.

[0070] Example 2: In order to test the stability of the phase center measured in Example 1, this example further performs the following steps based on the above steps 1 to 10:

[0071] Step 11: respectively obtain a first phase pattern with a beam of -30°, a second phase pattern with a beam of 0°, and a phase pattern with a beam of 30°.

[0072] Step 12: If at least one of the first phase direction diagram, the second phase direction diagram and the third phase direction diagram is not a straight line, execute step 13; if the first phase direction diagram, the second phase direction diagram and the third phase direction diagram are all straight lines, execute step 14;

[0073] Step 13: Move the turntable robot according to the method described in steps 6 to 9, and return to step 4.

[0074] Step 14: Output the phase center of the phased array antenna.

[0075] In step 11 to step 14, the stability of the measured phase center is determined by analyzing the shapes of the phase radiation patterns of the beams at -30°, 0° and 30°. If the measured phase center is unstable, further adjustments are made according to the method provided in Example 1.

[0076] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for determining the phase center of a phased array antenna radio frequency front end, characterized in that: The following steps are involved: S1: Install the phased array antenna on the vertical turntable of the turntable manipulator, adjust the geometric center of the opening plane of the horn antenna and the geometric center of the array surface of the phased array antenna to the rotation axis of the vertical turntable, and adjust the geometric center of the array surface of the phased array antenna to the rotation axis of the horizontal turntable of the turntable manipulator; S2: Obtaining a phase center offset of the phased array antenna and a phase pattern of a sum beam of the phased array antenna; S3: If the phase pattern is not a straight line, execute S4; if the phase pattern is a straight line, execute S9; S4: Compare the phase pattern with each reference pattern in a library to obtain multiple similarities; the library includes: a first reference pattern, used to indicate that in a plane rectangular coordinate system with the geometric center of the array surface as the origin, the phase center of the phased array antenna is located on the y-axis and above the geometric center of the array surface; a second reference pattern, used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located on the y-axis and below the geometric center of the array surface; a third reference pattern, used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located on the x-axis and to the left of the geometric center of the array surface; A fourth reference diagram is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located on the x-axis and to the right of the geometric center of the array surface; a fifth reference diagram is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located in the first quadrant; a sixth reference diagram is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located in the second quadrant; a seventh reference diagram is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located in the third quadrant; an eighth reference diagram is used to indicate that in the plane rectangular coordinate system, the phase center of the phased array antenna is located in the fourth quadrant; S5: selecting a reference image corresponding to a maximum value among multiple similarities; S6: Determine the moving direction of the turntable manipulator according to the selected reference image; S7: moving the turntable manipulator according to the moving direction and the phase center offset; S8: Return to S2; S9: Output the phase center of the phased array antenna.

2. The method for determining the phase center of a phased array antenna RF front end according to claim 1, characterized in that: Before S2, the following steps are also included: Performing beam calibration on the phased array antenna in the direction of the pitch angle by adjusting the vertical turntable; The beam of the phased array antenna is calibrated in the azimuth direction by adjusting the horizontal turntable.

3. The method for determining the phase center of a phased array antenna RF front end according to claim 2, characterized in that: Before S2, the following step is also included: performing equal phase leveling on the phased array antenna.

4. The method for determining the phase center of a phased array antenna RF front end according to claim 3, characterized in that: The equal phase leveling of the phased array antenna comprises the following steps: A1: obtaining a first phase average value of a first-row phase channel of the phased array antenna, obtaining a second phase average value of a last-row phase channel of the phased array antenna, and obtaining a first difference between the first phase average value and the second phase average value; A2: If the first difference is ≥10°, execute A3; if the first difference is <10°, execute A5; A3: Obtaining the azimuth axis adjustment angle according to the calculation model and the first difference; the expression of the calculation model is: adjustment angle = ; A4: adjusting the horizontal turntable according to the azimuth axis adjustment angle, and returning to A1; A5: Obtain a third phase average value of a first phase channel of the phase array antenna, obtain a fourth phase average value of a last phase channel of the phase array antenna, and obtain a second difference between the third phase average value and the fourth phase average value; A6: If the second difference is ≥10°, execute A7; if the second difference is <10°, equal phase leveling is completed; A7: Obtaining a pitch axis adjustment angle according to the calculation model and the second difference; A8: Adjust the vertical turntable according to the pitch axis adjustment angle, and return to A5.

5. A method for determining the phase center of a phased array antenna RF front end according to any one of claims 1 to 4, characterized in that: The following steps are also included: S10: respectively obtaining a first phase pattern with a beam of -30°, a second phase pattern with a beam of 0°, and a third phase pattern with a beam of 30°; S11: If at least one of the first phase direction diagram, the second phase direction diagram and the third phase direction diagram is not a straight line, execute S12; if the first phase direction diagram, the second phase direction diagram and the third phase direction diagram are all straight lines, execute S13; S12: Move the turntable robot according to the method described in S4 to S7, and return to S2; S13: Output the phase center of the phased array antenna.

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