Method for correcting two-dimensional phased array pointing by using difference sum ratio

Abstract

The invention relates to the related technical field of pointing correction, in particular to a method for correcting pointing of a two-dimensional phased array by using a difference-sum ratio. The method comprises the steps that pointing information can be rapidly extracted by adopting an electric scanning mode in combination with a phased array antenna and difference phase information, and pointing precision correction can be rapidly completed by adopting a polynomial interpolation method for accurately extracting the pointing information. The method has the technical effect that the corresponding relation between the beam pointing angle and the beam control angle is accurately positioned by using the difference-sum ratio. The data acquisition efficiency is improved by utilizing an electric scanning mode; and carrying out nonlinear interpolation encryption and correction on the grid by utilizing MATLAB (matrix laboratory).

Description

TECHNICAL FIELD

[0001] The present application relates to the field of pointing correction, and particularly relates to a method for correcting pointing of a two-dimensional phased array by using difference and ratio. BACKGROUND

[0002] The phased array radar improves the function and performance of the modern radar with its flexible space processing capability. The active phased array antenna realizes power synthesis in space, reduces the dependence of the system on the high-power transmitter, effectively improves the reliability of the system, simplifies the design of the feed network, and improves the volume, weight and loss of the antenna. Compared with the mechanical scanning fixed beam antenna, the antenna does not need a complex and heavy mechanical servo system, and can be installed conformally with the platform.

[0003] The single pulse technology has the advantages of high angle measurement precision, strong anti-interference capability and high data rate, and is widely used in many fields. In order to ensure the direction finding precision of the single pulse secondary radar, the pointing precision of the active phased array antenna must be higher than the direction finding precision requirement of the radar system. The installation position and cost of the antenna restrict us from realizing high pointing precision by increasing the size of the array, and the processing and installation of the antenna elements, the quantization error of the phase shifter, the parasitic phase modulation error and amplitude modulation error, the mutual coupling between the array elements, the temperature imbalance of the array and the failure of the array elements may all cause pointing errors and affect the pointing precision. Therefore, how to quickly correct the pointing of a two-dimensional active phased array antenna of a certain size becomes a problem that needs to be solved. SUMMARY

[0004] Therefore, the embodiments of the present application aim to provide a method for correcting the pointing of a two-dimensional phased array by using difference and ratio.

[0005] The present application provides a method for correcting the pointing of a two-dimensional phased array by using difference and ratio, comprising: Step S1, adjusting the beam control angle so that the beam control angle is a preset parameter, wherein the preset parameter is (FW, FY); Step S2, setting n=0 and m=0.

[0006] Step S3, adjusting the beam control angle, and collecting target information when the beam control angle is (FW+(n-1)*σ, FY+(m-1)*σ), (FW+n*σ, FY+(m-1)*σ) and (FW+(n-1)*σ, FY+m*σ) respectively; Wherein, σ is a pointing precision index; the target information includes: the signal vector of the port, the signal vector of the azimuth difference port and the signal vector of the elevation difference port; Step S4, obtaining the azimuth difference and ratio corresponding to (FW+(n-1)*σ, FY+(m-1)*σ) based on the target information. Obtain the azimuth difference and ratio corresponding to (FW+n*σ,FY+(m-1)*σ). Obtain the pitch difference and ratio corresponding to (FW+(n-1)*σ,FY+(m-1)*σ). Obtain the pitch aberration and ratio corresponding to (FW+(n-1)*σ,FY+m*σ). ; Wherein, the azimuth difference sum ratio is the ratio of the signal vector at the azimuth difference port to the signal vector at the pitch difference port; the pitch difference sum ratio is the ratio of the signal vector at the pitch difference port to the signal vector at the pitch difference port. Step S5, if <0、 <0、 <0、 <0, then let n=n+1, m=m+1; if <0、 <0、 <0、 If >0, then let n=n+1, m=m; if <0、 <0、 >0、 If >0, then let n=n+1, m=m-1; if <0、 >0、 <0、 <0, then let n=n, m=m+1; if <0、 >0、 >0、 If >0, then let n=n, m=m-1; if >0、 >0、 <0、 <0, then let n=n-1, m=m+1; if >0、 >0、 <0、 If >0, then let n=n-1, m=m; if >0、 >0、 >0、 If the value is greater than 0, then let n = n-1 and m = m-1; Repeat steps S3 to S5 until... <0、 >0、 <0 and If the target beam control angle is greater than 0, then the target beam control angle is (FW+(n-0.5)*σ,FY+(m-0.5)*σ); Wherein, the target beam control angle is the beam control angle corresponding to the preset beam pointing angle; the preset parameter is determined based on the preset beam pointing angle; Among them, the beam control angle is adjusted using an electronic scanning mode.

[0007] In some embodiments, it also includes: Using MATLAB, nonlinear interpolation is performed to refine and correct the target information corresponding to the beam control angles between (FW+n*σ,FY+m*σ) and (FW+(n-1)*σ,FY+(m-1)*σ). The target beam control angle is determined when the azimuth difference ratio and the elevation difference ratio are both zero.

[0008] This application provides a method for correcting the pointing of a two-dimensional phased array using difference and ratio. First, step S1 is performed to adjust the beam control angle to a preset parameter (FW, FY). Then, step S2 sets n=0 and m=0. Steps S3 to S5 are then repeated until… <0、 >0、 <0 and If the target beam control angle is greater than 0, then the target beam control angle is (FW+(n-0.5)*σ,FY+(m-0.5)*σ). The beam control angle is adjusted using an electronic scanning mode. Based on the scheme provided in this application, the beam control angle corresponding to the preset beam pointing angle (FW,FY) can be quickly found. Attached Figure Description

[0009] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments of this application in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0010] Figure 1 This is a flowchart illustrating a method for correcting the pointing of a two-dimensional phased array using difference and ratio, provided in one embodiment of this application. Detailed Implementation

[0011] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0012] Phased array radars, with their flexible airspace processing capabilities, enhance the functionality and performance of modern radars. Active phased array antennas achieve power combining in space, reducing the system's dependence on high-power transmitters, effectively improving system reliability, and simplifying the design of the feed network. This improves the antenna's size, weight, and loss characteristics, and compared to mechanically scanned fixed-beam antennas, eliminates the need for complex and bulky mechanical servo systems. The antennas require minimal installation space and can be conformally mounted to the platform.

[0013] Monopulse technology boasts advantages such as high angle measurement accuracy, strong anti-interference capability, and high data rate, leading to its widespread application in numerous fields. To ensure the direction-finding accuracy of monopulse-based secondary radar, the pointing accuracy of active phased array antennas must exceed the direction-finding accuracy requirements of the radar system. However, antenna installation location and cost constraints prevent achieving high pointing accuracy by increasing array size. Furthermore, issues such as antenna element fabrication and installation, quantization errors of phase shifters, parasitic phase modulation errors, parasitic amplitude modulation errors, inter-element coupling, array temperature imbalance, and element failure can all cause pointing errors, affecting pointing accuracy. Therefore, how to quickly correct the pointing of a two-dimensional active phased array antenna of a certain size has become an urgent problem to solve.

[0014] The main methods for correction at present are: By controlling a robotic arm to test the radiation pattern of a phased array antenna, the peak angle of the sum pattern or the null angle of the difference pattern is extracted as the beam pointing angle. The disadvantage is that when the beam width is wide, the beam pointing of the sum pattern changes significantly, which cannot meet the high-precision pointing requirements. When the beam pointing is determined by the difference pattern, a high-precision robotic arm is required to collect the accurate null, which also cannot meet the high-precision pointing requirements. At the same time, the acquisition speed is relatively slow.

[0015] To address the aforementioned problems, this application provides a solution that utilizes electronic scanning mode combined with phased array antenna and difference phase information to quickly extract pointing information. Accurate pointing information extraction is then achieved through polynomial interpolation, enabling rapid pointing accuracy correction. The technical advantages of this invention are: accurately locating the correspondence between the beam pointing angle and beam control angle using difference and ratio; improving data acquisition efficiency through electronic scanning mode; and using MATLAB for nonlinear interpolation to refine and correct the mesh.

[0016] The principles and methods of pointing and positioning are as follows: The azimuth channel's pattern is flat in phase near the beam direction, while the azimuth difference channel's pattern flips in phase to the left and right of the beam direction, and the pitch difference channel's pattern flips in phase to the up and down of the beam direction. For the trigonometric function cos(θ), cos(θ) > 0 when -90° < θ < 90°; and cos(θ) < 0 when 90° < θ < 270°.

[0017] For example, the signal vector of the port is The difference port signal vector pointing to the left of the beam is , Then the difference and ratio ; The difference port signal vector pointing to the right of the beam is , Then the difference and ratio .

[0018] Theoretically, a1-a=-90°, a2-a=90°. However, in actual testing, the phase difference may fluctuate around -90° and 90° due to instrument and environmental factors. To avoid the influence of phase fluctuations, a compensating phase b=-90° can be added; therefore, when the beam points to the left... <0, when the beam is pointing to the left Since Real(K) is greater than 0, the beam control angle corresponding to the actual beam pointing angle can be determined by the sign of Real(K).

[0019] Figure 1 This is a flowchart illustrating a method for correcting the pointing of a two-dimensional phased array using difference and ratio, provided in one embodiment of this application. Figure 1 As shown, the method includes the following:

[0020] Step S1: Adjust the beam control angle so that the beam control angle is a preset parameter, where the preset parameter is (FW, FY). Step S2, let n=0 m=0.

[0021] Step S3: Adjust the beam control angle and collect target information when the beam control angle is (FW+(n-1)*σ,FY+(m-1)*σ), (FW+n*σ,FY+(m-1)*σ), and (FW+(n-1)*σ,FY+m*σ); Wherein, σ is the pointing accuracy index; the target information includes: the signal vector of the azimuth difference port, the signal vector of the azimuth difference port, and the signal vector of the pitch difference port; Step S4: Based on the target information, obtain the azimuth difference and ratio corresponding to (FW+(n-1)*σ, FY+(m-1)*σ). Obtain the azimuth difference and ratio corresponding to (FW+n*σ,FY+(m-1)*σ). Obtain the pitch difference and ratio corresponding to (FW+(n-1)*σ,FY+(m-1)*σ). Obtain the pitch aberration and ratio corresponding to (FW+(n-1)*σ,FY+m*σ). ; Wherein, the azimuth difference sum ratio is the ratio of the signal vector at the azimuth difference port to the signal vector at the pitch difference port; the pitch difference sum ratio is the ratio of the signal vector at the pitch difference port to the signal vector at the pitch difference port. Step S5, if <0、 <0、 <0、 <0, then let n=n+1, m=m+1; if <0、 <0、 <0、 If >0, then let n=n+1, m=m; if <0、 <0、 >0、 If >0, then let n=n+1, m=m-1; if <0、 >0、 <0、 <0, then let n=n, m=m+1; if <0、 >0、 >0、 If >0, then let n=n, m=m-1; if >0、 >0、 <0、 <0, then let n=n-1, m=m+1; if >0、 >0、 <0、 If >0, then let n=n-1, m=m; if >0、 >0、 >0、 If the value is greater than 0, then let n = n-1 and m = m-1; Repeat steps S3 to S5 until... <0、 >0、 <0 and If the target beam control angle is greater than 0, then the target beam control angle is (FW+(n-0.5)*σ,FY+(m-0.5)*σ); Wherein, the target beam control angle is the beam control angle corresponding to the preset beam pointing angle; the preset parameter is determined based on the preset beam pointing angle; Among them, the beam control angle is adjusted using an electronic scanning mode.

[0022] With this setup, the beam control angle corresponding to the preset beam pointing angle can be quickly found based on the solution provided in this application.

[0023] Furthermore, in some embodiments, the method further includes: using MATLAB to perform nonlinear interpolation to encrypt and correct the target information corresponding to the beam control angles between (FW+n*σ,FY+m*σ) and (FW+(n-1)*σ,FY+(m-1)*σ); and determining the beam control angles corresponding to the azimuth difference ratio and the elevation difference ratio being 0 as the target beam control angles.

[0024] Specifically, the beam control angle between (FW+n*σ,FY+m*σ) and (FW+(n-1)*σ,FY+(m-1)*σ) is the beam control angle (W, Y). The value range of W is: FW+n*σ to (FW+(n-1)*σ; the value range of Y is: FY+m*σ to (FW+(m-1)*σ. This setting can more accurately determine the target beam control angle.

[0025] The above solution will be illustrated with a practical example below: Set up the signal source and antenna according to the far-field condition R≥2·D2 / λ, where R is the distance between the transmitting and receiving antennas and D is the diameter of the antenna aperture. The horn antenna is installed directly opposite the active phased array antenna. The output port of the vector network analyzer is connected to the transmitting horn, and the other three ports are connected to the sum, azimuth, and elevation difference ports, respectively. Carefully adjust the antenna angle and horn position so that the amplitude of the sum channel output signal reaches the maximum value while the amplitude of the difference channel output signal reaches the minimum value, and record this position as the normal (0,0). Note that the output signal amplitude of the vector network analyzer needs to be adjusted to ensure the radar receiver operates in linear amplification mode; control the turntable to rotate to (-FW, -FY). If the pointing accuracy requirement is ≤σ, then issue beam control angles A(FW+(n-1)*σ,FY+(m-1)*σ), B(FW+n*σ,FY+(m-1)*σ), and C(FW+(n-1)*σ,FY+m*σ) respectively, while simultaneously acquiring the signal vectors of the azimuth and azimuth difference (n=1, m=1); calculate the azimuth difference and ratio. , Pitch difference and ratio , ;like <0、 >0、 <0、 If the beam pointing angle is greater than 0, the beam control angle corresponding to the beam pointing angle (FW, FY) is (FW+σ / 2, FY+σ / 2); if <0、 <0、 <0、 If <0, then n=n+1, m=m+1, reissue beam control angles A(FW+(n-1)*σ,FY+(m-1)*σ), B(FW+n*σ,FY+(m-1)*σ), C(FW+(n-1)*σ,FY+m*σ), and simultaneously acquire the signal vectors of azimuth difference azimuth; if <0、 <0、 <0、 If >0, then n=n+1, m=m, and the beam control angles A(FW+(n-1)*σ,FY+(m-1)*σ), B(FW+n*σ,FY+(m-1)*σ), and C(FW+(n-1)*σ,FY+m*σ) are reissued, while simultaneously acquiring the signal vectors of the azimuth difference azimuth and the sigma difference azimuth. <0、 <0、 >0、 If >0, then n=n+1, m=m-1, and the beam control angles A(FW+(n-1)*σ,FY+(m-1)*σ), B(FW+n*σ,FY+(m-1)*σ), and C(FW+(n-1)*σ,FY+m*σ) are reissued, while simultaneously acquiring the signal vectors of the azimuth difference azimuth and the sigma difference azimuth. <0、 >0、 <0、 If <0, then n=n, m=m+1, reissue beam control angles A(FW+(n-1)*σ,FY+(m-1)*σ), B(FW+n*σ,FY+(m-1)*σ), C(FW+(n-1)*σ,FY+m*σ), and simultaneously acquire the signal vectors of the azimuth difference azimuth and the sigma difference azimuth. <0、 >0、 >0、 If >0, then n=n, m=m-1, reissue beam control angles A(FW+(n-1)*σ,FY+(m-1)*σ), B(FW+n*σ,FY+(m-1)*σ), C(FW+(n-1)*σ,FY+m*σ), and simultaneously acquire the signal vectors of azimuth difference azimuth and sigma difference azimuth; if >0、 >0、 <0、 If <0, then n=n-1, m=m+1, reissue beam control angles A(FW+(n-1)*σ,FY+(m-1)*σ), B(FW+n*σ,FY+(m-1)*σ), C(FW+(n-1)*σ,FY+m*σ), and simultaneously acquire the signal vectors of azimuth difference azimuth; if >0、 >0、 <0、 If >0, then n=n-1, m=m, reissue beam control angles A(FW+(n-1)*σ,FY+(m-1)*σ), B(FW+n*σ,FY+(m-1)*σ), C(FW+(n-1)*σ,FY+m*σ), and simultaneously acquire the signal vectors of azimuth difference azimuth; if >0、 >0、 >0、 If the value is greater than 0, then n = n-1, m = m-1. The beam control angles A(FW+(n-1)*σ, FY+(m-1)*σ), B(FW+n*σ, FY+(m-1)*σ), and C(FW+(n-1)*σ, FY+m*σ) are reissued, while simultaneously acquiring the signal vectors of the azimuth difference and the sigma difference. Steps 4, 5, 6, 7, 8, 9, 10, 11, and 12 are repeated to determine the beam control angle corresponding to the beam pointing angle (FW, FY) as (FW+σ / 2, FY+σ / 2). The above operations are repeated in a certain angular step to complete the beam pointing correction of the two-dimensional active phased array. Small-step correction is achieved by using MATLAB nonlinear interpolation to refine the two-dimensional mesh. In MATLAB, using nonlinear interpolation to refine the two-dimensional mesh and perform small-step correction is a common task, especially in image processing, scientific computing, and engineering. We will not elaborate on this here.

[0026] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0027] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A method for correcting the pointing of a two-dimensional phased array using difference and ratio, characterized in that, include: Step S1: Adjust the beam control angle so that the beam control angle is a preset parameter, where the preset parameter is (FW, FY). Step S2, let n=0, m=0. Step S3: Adjust the beam control angle and collect target information when the beam control angle is (FW+(n-1)*σ,FY+(m-1)*σ), (FW+n*σ,FY+(m-1)*σ), and (FW+(n-1)*σ,FY+m*σ); Wherein, σ is the pointing accuracy index; the target information includes: the signal vector of the azimuth difference port, the signal vector of the azimuth difference port, and the signal vector of the pitch difference port; Step S4: Based on the target information, obtain the azimuth difference and ratio corresponding to (FW+(n-1)*σ, FY+(m-1)*σ). Obtain the azimuth difference and ratio corresponding to (FW+n*σ,FY+(m-1)*σ). Obtain the pitch difference and ratio corresponding to (FW+(n-1)*σ,FY+(m-1)*σ). Obtain the pitch aberration and ratio corresponding to (FW+(n-1)*σ,FY+m*σ). ; Wherein, the azimuth difference sum ratio is the ratio of the signal vector at the azimuth difference port to the signal vector at the pitch difference port; the pitch difference sum ratio is the ratio of the signal vector at the pitch difference port to the signal vector at the pitch difference port. Step S5, if <0、 <0、 <0、 <0, then let n=n+1, m=m+1; if <0、 <0、 <0、 If >0, then let n=n+1, m=m; if <0、 <0、 >0、 If >0, then let n=n+1, m=m-1; if <0、 >0、 <0、 <0, then let n=n, m=m+1; if <0、 >0、 >0、 If >0, then let n=n, m=m-1; if >0、 >0、 <0、 <0, then let n=n-1, m=m+1; if >0、 >0、 <0、 If >0, then let n=n-1, m=m; if >0、 >0、 >0、 If the value is greater than 0, then let n = n-1 and m = m-1; Repeat steps S3 to S5 until... <0、 >0、 <0 and If the target beam control angle is greater than 0, then the target beam control angle is (FW+(n-0.5)*σ,FY+(m-0.5)*σ); Wherein, the target beam control angle is the beam control angle corresponding to the preset beam pointing angle; the preset parameter is determined based on the preset beam pointing angle; Among them, the beam control angle is adjusted using an electronic scanning mode.

2. The method for correcting the pointing of a two-dimensional phased array using difference and ratio as described in claim 1, characterized in that, Also includes: Using MATLAB, nonlinear interpolation is performed to refine and correct the target information corresponding to the beam control angles between (FW+n*σ,FY+m*σ) and (FW+(n-1)*σ,FY+(m-1)*σ). The target beam control angle is determined when the azimuth difference ratio and the elevation difference ratio are both zero.

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