A gradient-based beam peak search method and apparatus

Abstract

This invention discloses a gradient-based beam peak search method, relating to the field of antenna testing technology. First, the measurement grid size in the spherical coordinate system along the horizontal and elevation directions is set according to the half-power bandwidth of the antenna under test. The radiated power values ​​on the measured test grid are interpolated to obtain the radiation pattern within the grid coverage area. Next, local maxima points of the radiation pattern are retrieved, and the positions of these local maxima points are used as the center of the region where beam peaks may occur. Secondary measurements are performed around these local maxima points to obtain the radiated power. Finally, using the maximum radiated power value from the secondary measurements as the initial position, the test position is iteratively updated using the gradient of the current position, outputting the peak position and the magnitude of the radiated power at the peak. This invention also discloses a gradient-based beam peak search device, which can significantly reduce the number of tests required while ensuring the accuracy of the search results.

Description

Technical Field

[0001] This invention relates to the field of antenna testing technology, and in particular to a gradient-based beam peak search method and apparatus. Background Technology

[0002] In modern wireless communication systems, antenna beamforming technology plays a crucial role in massive MIMO (Multiple-Input Multiple-Input) and millimeter-wave applications. With the development of 5G and future 6G mobile communication systems, beamforming antenna systems are widely used in base stations and user equipment to enhance signal coverage, improve data transmission rates, and increase spectral efficiency. To optimize antenna beamforming performance, beam peak search has become an important testing item, rapidly locating the direction of maximum signal gain in the antenna radiation pattern, i.e., the position of the main beam peak. The beam peak position not only affects antenna design but also directly relates to system signal quality and user experience.

[0003] Traditional beam peak search methods typically determine the peak direction by traversing the radiated power within a three-dimensional (3D) test space. In 3GPP and CTIA standards, the specified beam peak testing methods include the equal-step method and the equal-density method. The equal-step method involves measuring at certain angular intervals in the azimuth and elevation dimensions of a spherical coordinate system. Discussions suggest that at least a test step size of 7.5° and a total of 1106 measurements are required to ensure the accuracy of the test results. The equal-density method divides the sphere into a specified number of equally sized regions based on the Voronoi Region. To ensure the accuracy of the test results, at least 800 regions, or 800 measurements, are required.

[0004] However, with the increasing scale of antenna arrays, the efficiency of traditional methods can no longer meet the demands. Massive MIMO antenna systems may contain dozens or even hundreds of antenna elements, and point-by-point measurements are extremely resource-intensive in terms of time and computation. Especially in high-frequency millimeter-wave communication, where beamwidths are narrower and radiation patterns are more complex, angle-by-angle measurements are not only time-consuming but also prone to introducing measurement errors. Therefore, to improve testing efficiency and accuracy, fast beam peak search methods have emerged.

[0005] The core idea of ​​Fast BeamPeak Search (FBSS) technology is to avoid ergonomic measurements of the beam direction through optimization methods, thereby locating the peak position of the main beam with fewer tests. This technology also plays a crucial role in beam tracking in dynamic environments. For example, in scenarios where user equipment or base station antennas are moving in real time, FBSS can rapidly adjust the beam direction to ensure the signal remains aligned with the target, thus improving user experience and network reliability. As the complexity of wireless communication scenarios continues to increase, FBSS technology will continue to evolve in the future to support a wider range of applications and higher performance requirements.

[0006] Common optimization methods include genetic algorithms and particle swarm optimization (PSO). In fast beam peak search, these methods possess global search capabilities, making them particularly effective in large-scale antenna arrays and complex radiation patterns. However, genetic algorithms simulate biological evolution through selection, crossover, and mutation, a process requiring multiple generations of iterations to gradually approach the optimal solution, resulting in significant computational overhead. PSO relies on the cooperation of a swarm of particles, updating the velocity and position of each particle to find the optimal solution, also requiring numerous iterations and a large number of candidate points to achieve convergence. Therefore, there is an urgent need for a method that can converge quickly with fewer test points and iterations, significantly improving computational efficiency while maintaining optimization effectiveness. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a gradient-based beam peak search method and apparatus, which can perform fast and high-precision beam peak search and positioning for any antenna under test.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] A gradient-based beam peak search method proposed according to the present invention includes:

[0010] First, fix the device under test (DUT) on the turntable and position its geometric center at the center of the test area. Using the geometric center of the DUT as the origin of the spherical coordinate system and the distance between the signal receiving device and the DUT as the radial distance of the spherical coordinate system, set the test intervals in the elevation and azimuth dimensions of the spherical coordinate system according to the half-power bandwidth of the electric and magnetic surfaces of the antenna in the DUT, thus forming a test grid with the azimuth and elevation angles as coordinates at a fixed radial distance.

[0011] Based on the angular position indicated by each grid point in the test grid, the turntable is used to control the orientation of the device under test. After traversing the angles indicated by the test grid and measuring the radiation power at the angle indicated by each grid point in the test grid, the test grid is interpolated using the interpolation method to estimate the complete radiation pattern within the test area.

[0012] Next, the locations of local maxima are obtained from the estimated complete radiation pattern, and these locations are used as the center of the secondary measurement region. Around the center of each secondary measurement region, multiple locations of secondary measurements are determined at a distance smaller than the grid spacing within the test grid, and the set of radiated power is measured at these locations.

[0013] Finally, the maximum radiant power is obtained from the set of radiant powers measured in the second measurement. The position corresponding to the maximum radiant power in the second measurement is used as the initial position. The test position is updated each time according to the gradient search algorithm. When the gradient search algorithm converges to a certain position and does not change, the position and the magnitude of the radiant power measured at that position are output.

[0014] As a further optimization of the gradient-based beam peak search method described in this invention, the area around the center position of each secondary measurement region includes both the orthogonal direction and the diagonal direction of the center position of each secondary measurement region.

[0015] As a further optimization scheme for the gradient-based beam peak search method described in this invention, the specific steps are as follows:

[0016] Step 1: In a spherical coordinate system with the geometric center of the device under test as the origin. In the equation, the pitch angle θ ranges from -90° to θ to 90°, and the azimuth angle... Within the range r is the radial distance; within the range of elevation angle variation, it is the half-power beamwidth θ of the antenna in the device under test on the θ plane. 3dB N angles are selected at intervals, and within the range of horizontal angle variation, the antenna under test is used in... Half-power beamwidth on the surface M angles are selected at intervals to form a test grid with dimensions N×M; the orientation of the device under test is changed by a turntable. n = 1...N, m = 1...M, θ n For the selected nth pitch angle, To select the m-th horizontal angle, a signal receiving device is used to... Radiated power measured at [location] Receive;

[0017] Step 2: Interpolate the test grid using interpolation to obtain the complete interpolated radiation pattern. This radiation pattern contains V local maxima, which are the center points of the secondary measurement area. Record the position of the v-th local maxima as... θ vLet v be the pitch angle corresponding to the location of the v-th local maximum point. Let E(x) be the horizontal angle corresponding to the location of the v-th local maximum point. Record the radiated power of these local maximum points as E(x). v );

[0018] Step 3, at the v-th local maximum point At that point, with Δθ=θ n+1 -θ n , For interval, θ n+1 To test the θ value corresponding to the (n+1)th row of the grid, Δθ is the difference between the θ value corresponding to the (n+1)th row and the θ value corresponding to the nth row. For the (m+1)th row The value corresponding to the m-th row The difference in value For the test grid row (m+1) corresponding to Value, in Radiation power was measured again at q' positions along the orthogonal and diagonal directions. The radiation power measured at each of the q positions was denoted as .

[0019] The radiation power E(x) measured in step 2 v ) and the measured in step 3 Merge into a set E v To obtain the location of the maximum radiated power in the set. θ ini The pitch angle corresponding to the location of the maximum value in the set. The horizontal angle corresponding to the position of the maximum value in the set;

[0020] Step 4, with x ini Using the measured radiated power at that location as the starting point for gradient search, the gradient g(x) at the current location is calculated. ini );

[0021] Step 5: Suppose that determining the peak position requires K position updates. At the k-th test position... At θ k Let be the pitch angle at the k-th test position. Let g(x) be the horizontal angle at the k-th test position, based on the gradient g(x) at the k-th test position. k Solving for the search direction ρ from the k-th test position to the (k+1)-th test position required to update the position yields the desired update location. k and search step size s k Find the (k+1)th test position. for

[0022] x k+1 =xk +s k ρ k ;

[0023] Where, θ k+1 Let be the pitch angle at the (k+1)th test position. The horizontal angle at the (k+1)th test position;

[0024] Step 6: Set the maximum number of iterations Max_iter, and repeat step 5 until either of the following termination conditions is met: (1) the number of iterations reaches Max_iter; (2) the result of three consecutive iterations is x. k+1 =x k ;

[0025] After the iteration terminates, the output shows the converged beam peak position x. peak And the corresponding radiated power E(x) peak ).

[0026] As a further optimization of the gradient-based beam peak search method described in this invention, q' is 8.

[0027] As a further optimization scheme of the gradient-based beam peak search method described in this invention, g(x k The calculation formula for ) is as follows:

[0028]

[0029] Wherein, Δg θ and These represent the directions along the pitch angle θ and the horizontal angle in the spherical coordinate system, respectively. The change in direction for The magnitude of the radiated power at that location, for The magnitude of the radiated power at that location, for The magnitude of the radiated power at that location.

[0030] As a further optimization scheme of the gradient-based beam peak search method described in this invention, ρ k The calculation formula is as follows:

[0031]

[0032] Where |·| represents g(x) k ) of the model.

[0033] As a further optimization scheme of the gradient-based beam peak search method described in this invention, s k Including s k,1 s k,2and s k,3 , s k,1 、s k,2 and s k,3 The calculation formula of is as follows:

[0034] Based on the k-th position x where it is currently located k and the search direction ρ from the k-th position to the k + 1-th position k , according to the sufficient descent condition, set the initial step size s k,1 to be

[0035]

[0036] Substitute s k,1 into the position update formula to obtain the first calculated (k + 1)-th position x k+1,1 , compare the radiation power E(x k+1,1 ) at x k+1,1 and the radiation power E(x k ) at x k ; if E(x k+1,1 ) > E(x k ), then increase the step size in the ρ k direction;

[0037] Let ξ(s k ) = E(x k + s k ρ k ), E(x k + s k ρ k ) is the radiation power at x k + s k ρ k , ξ(s k ) is the radiation power with the step size as the independent variable in the direction of ρ at x k , then the quadratic step size s k is k,2 to be

[0038]

[0039] where ξ(0) is the radiation power at x k when s k is 0, that is, at x k , ξ′(0) is the discrete derivative of the radiation power at x k,1 , ξ(s k+1,1 ) is the radiation power at x k+1,1 ; at x k,2 , substitute s k+1,2 into the position update formula to obtain the second calculated (k + 1)-th position x

[0040] If E(x) k+1,2 )>E(x k+1,1 ), E(x) k+1,2 ) is x k+1,2 Radiated power at point E(x) k+1,1 ) is x k+1,1 The radiated power at that point is expressed in cubic steps s. k,3 Increase ρ k Let A and B represent complex polynomials, and s be the step size in the direction. k,3 The calculation formula is as follows:

[0041]

[0042] The formulas for calculating A and B are as follows:

[0043]

[0044] Where, ξ(s) k,2 ) is x k +s k,2 ρ k The radiation power at that location.

[0045] As a further optimization scheme of the gradient-based beam peak search method described in this invention, at the k-th position x k At that point, the search direction ρ required to update the position is calculated based on the gradient. k Then, through N s Secondary radiation power measurement adjusts the search step size s k The calculation formula is:

[0046] s k =s k,1 +(N s -1)s k,2 +max(N s -2,0)s k,3 .

[0047] A gradient-based beam peak search device, comprising:

[0048] The device under test (DUT) and the turntable are used. The DUT is fixed on the turntable, and the geometric center of the DUT is located at the center of the test area.

[0049] The test grid forming module is used to form a test grid with the geometric center of the device under test as the origin of the spherical coordinate system, the distance between the signal receiving device and the device under test as the radial distance of the spherical coordinate system, and the test intervals set according to the half-power bandwidth of the electric and magnetic surfaces of the antenna in the device under test in the elevation and azimuth dimensions of the spherical coordinate system, thereby forming a test grid with azimuth and elevation angles as coordinates at a fixed radial distance.

[0050] The estimation module is used to control the orientation of the device under test by using a turntable to traverse the angles indicated by each grid point in the test grid, measure the radiation power at the angle indicated by each grid point in the test grid, and then estimate the complete radiation pattern in the test area by interpolating the test grid using an interpolation method.

[0051] The secondary measurement module is used to obtain the locations of local maxima from the estimated complete radiation pattern, and use the locations of these local maxima as the center locations of the secondary measurement regions. Around the center location of each secondary measurement region, multiple secondary measurement locations are determined at a distance smaller than the grid spacing within the test grid, and the set of radiated power is measured at these secondary measurement locations.

[0052] The location search module is used to obtain the maximum radiation power from the set of radiation power measured in the second measurement. The position corresponding to the maximum radiation power in the second measurement is used as the initial position. The test position is updated each time according to the gradient search algorithm. When the gradient search algorithm converges to a certain position and does not change, the position and the radiation power measured at that position are output.

[0053] As a further optimization scheme for the gradient-based beam peak search device described in this invention, the turntable is rotated by software control to an orientation consisting of horizontal and pitch angles with a resolution of 1°.

[0054] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects:

[0055] (1) This solution has no special requirements for the antenna under test, does not require instruments other than those used in conventional testing, and does not require additional calibration steps. It can be tested directly with existing equipment and has extremely high feasibility.

[0056] (2) The amount of test data required by this solution is much smaller than that of the traversal solution, thus effectively reducing the demand for human and material resources during the testing process, and reducing power consumption and equipment load;

[0057] (3) This scheme can quickly locate the beam peak by using a gradient path along the gain direction, which significantly reduces the number of test points and avoids the inefficient process of point-by-point testing in the traditional traversal scheme. The deviation of the search results from the traversal scheme is less than 0.5dB, and the statistical average error relative to the true value is about 0.2dB, which ensures the high precision and accuracy of the search results, indicating that this scheme has a very high application prospect. Attached Figure Description

[0058] Figure 1 This is a diagram of the test system device architecture of an embodiment of the present invention;

[0059] Figure 2This is a flowchart of the peak search method in an embodiment of the present invention;

[0060] Figure 3 This is a three-dimensional radiation pattern in an embodiment of the present invention;

[0061] Figure 4 This is the radiation map estimated by interpolation from the data measured by the test grid in an embodiment of the present invention;

[0062] Figure 5 This is a schematic diagram illustrating the use of a gradient algorithm to search for the beam peak position in an embodiment of the present invention. Detailed Implementation

[0063] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0064] A gradient-based beam peak search device includes an antenna under test, a turntable, and a probe antenna.

[0065] The antenna under test is used to radiate electromagnetic waves. In actual deployment scenarios, it can be any single-beam antenna such as a phased array or a flat panel antenna.

[0066] The turntable is used to fix the antenna under test and achieve 3D rotation with a resolution of 1° during the test, ensuring that the radiated power of the antenna can be accurately measured in all directions.

[0067] The probe antenna serves as a signal receiving device, used to receive electromagnetic waves radiated by the antenna under test and report the effective radiated power (EIRP) to the control device.

[0068] The device specifically includes:

[0069] The device under test (DUT) and the turntable are used. The DUT is fixed on the turntable, and the geometric center of the DUT is located at the center of the test area.

[0070] The test grid forming module is used to form a test grid with the geometric center of the device under test as the origin of the spherical coordinate system, the distance between the signal receiving device and the device under test as the radial distance of the spherical coordinate system, and the test intervals set according to the half-power bandwidth of the electric and magnetic surfaces of the antenna in the device under test in the elevation and azimuth dimensions of the spherical coordinate system, thereby forming a test grid with azimuth and elevation angles as coordinates at a fixed radial distance.

[0071] The estimation module is used to control the orientation of the device under test by using a turntable to traverse the angles indicated by each grid point in the test grid, measure the radiation power at the angle indicated by each grid point in the test grid, and then estimate the complete radiation pattern in the test area by interpolating the test grid using an interpolation method.

[0072] The secondary measurement module is used to obtain the locations of local maxima from the estimated complete radiation pattern, and use the locations of these local maxima as the center locations of the secondary measurement regions. Around the center location of each secondary measurement region, multiple secondary measurement locations are determined at a distance smaller than the grid spacing within the test grid, and the set of radiated power is measured at these secondary measurement locations.

[0073] The location search module is used to obtain the maximum radiation power from the set of radiation power measured in the second measurement. The position corresponding to the maximum radiation power in the second measurement is used as the initial position. The test position is updated each time according to the gradient search algorithm. When the gradient search algorithm converges to a certain position and does not change, the position and the radiation power measured at that position are output.

[0074] Based on the above-described beam peak search device structure, the present invention also includes a beam peak search method:

[0075] First, the measurement grid size in the spherical coordinate system along the horizontal and elevation directions is set according to the half-power bandwidth of the antenna under test. The measured sparse grid data is interpolated to obtain the radiation pattern within the grid coverage area. Next, the vertices of the radiation pattern are retrieved, and the vertex positions are determined as the center of the region where the beam peak may occur. Secondary measurements are performed around the vertices to further narrow down the region where the beam peak may occur. Finally, the maximum value in the secondary measurements is used as the initial position, and the test position is iteratively updated using the gradient of the current position. The search program terminates after the iteration results converge, and the peak position and the magnitude of the radiated power at the peak are output.

[0076] In one implementation case, the topology of the test setup is shown in the attached figure. Figure 1 As shown, the setup includes the antenna under test, a turntable, and a probe antenna. The antenna under test is fixed on the turntable, and a horizontal angle is set. The test range is [0°, 180°], and the elevation angle θ test range is [-90°, 90°]. During the test, the antenna under test is fixed at the center of the turntable and rotates 3D with the turntable at a resolution of 1°. The probe antenna is fixed in position and kept aligned with the center of the antenna under test. The radiation pattern of the antenna under test pointing at [0°, 0°] is shown in the attached figure. Figure 3 As shown. During the k-th measurement, the probe antenna receives data from the antenna under test in the following direction: The signal power emitted at that time is reported to a spectrum analyzer, power meter, or other power measurement device, therefore in x k EIRP in the direction can be represented as E(x) k ).

[0077] For the electric surface half-power beamwidth θ 3dB The half-power beamwidth of the magnetic surface is The antenna under test, with A test grid of dimension N×M covering the entire test area is formed, with each grid cell size defined. The EIRP at each grid point is recorded, and the complete radiation pattern within the test area is estimated with a resolution of 1° based on interpolation. (See attached diagram) Figure 4 As shown, find the local maxima. As a candidate location for beam peaking. In x v The orthogonal and oblique diagonal directions record the EIRP set E(x) of the secondary measurements. v Find the position corresponding to the maximum EIRP within the set, and use this position as the starting point for gradient search.

[0078] x ini The starting position is [position], and the test position is [position]. At x k At each location Δg θ and To perform tests at intervals in orthogonal directions, according to the gradient calculation formula...

[0079]

[0080] Get x k The gradient at that point, and then according to g(x) k Estimate the next test position x k+1

[0081] x k+1 =x k +s k ρ k

[0082] Where ρ k For x k+1 relative to x k direction, s k To reach x k+1 The step size required. Through multiple iterations, the algorithm eventually converges to the position x. peak This refers to the beam peak position, corresponding to the EIRP magnitude E(x). peak This refers to the beam peak size, which enables the location and testing of the beam peak.

[0083] To further illustrate the present invention, specific testing methods will be introduced below based on the above-described testing device example.

[0084] like Figure 2 As shown, the specific steps are as follows:

[0085] 1. Traverse the θ plane within [-90°, 90°], Within the plane [0°, 180°], the half-power beamwidth θ of the antenna under test is respectively... 3dB and For each location on the interval test grid, the EIRP, after considering the boundary, forms a matrix of dimension N×M. During the traversal, the antenna under test continues to transmit uplink signals and completes 3D rotation via a turntable. The probe antenna is connected to power measurement equipment such as a spectrum analyzer and power meter to record the received signal power.

[0086] 2. Interpolate the test grid data to obtain a radiation power pattern matrix with a resolution of 1° and a size of 181×181 within the test area. Obtain the locations x-coordinates of all local maxima within this matrix. v v = 1, 2, ..., V. At each local maximum x v The four orthogonal positions, plus the vectors of the two directions with the larger EIRP measured from the four orthogonal positions, and the diagonal direction pointing to them, for a total of five positions x. v,i The test is performed again for v = 1, 2, ..., V, i = 1, 2, ..., 5, and x. v and x v,i Common second test position and the corresponding EIRP set

[0087] 3. Select The maximum value corresponding to x, the starting position of the gradient search algorithm ini The beam peak position x is found through K iterations. peak and the corresponding EIRP size E(x) peak ).

[0088] 4. At the k-th position x k When measuring at a location, the gradient at that location is calculated according to the gradient calculation formula.

[0089]

[0090] Wherein, Δg θ and These represent the gradient calculations along the θ direction and... The increment required for the direction.

[0091] 5. Based on the gradient information at the location and the position update formula, the (k+1)th test location x can be obtained. k+1 for

[0092] x k+1 =x k +s k ρ k

[0093] Where ρ k For x k+1 relative to x k direction, s k To reach x k+1 The step size that needs to be traversed. ρ k and s k ρ is calculated based on the gradient at the location. k The normalized gradient vector, i.e.

[0094]

[0095] Where |·| represents g(x) k ) of the model.

[0096] To perform a thorough search with the largest possible step size in the same direction, based on the sufficient ascent criterion, the step size is progressively increased using primary, secondary, and tertiary calculation formulas while ensuring increased radiated power. The primary calculation formula for the step size is as follows:

[0097]

[0098] s k,1 Substituting this into the position update formula, we can calculate x. k+1,1 Compare E(x) k+1,1 ) and E(x k If E(x) k+1,1 )>E(x k If the step size is increased in that direction, then the second-order step size s is set. k,2 for

[0099]

[0100] Where, ξ(s) k )=E(x k +s k ρ k ). In x k+1,1 At this location, s k,2 Substituting this into the position update formula, we can calculate x. k+1,2 Similarly, if E(x) k+1,2 )>E(x k+1,1 Then, with a third-order step size s k,3 Increase the step size in this direction, calculated using the following formula:

[0101]

[0102] The formulas for calculating A and B are as follows:

[0103]

[0104] As a further optimization scheme of the gradient-based beam peak search method described in this invention, at the k-th position x k At that point, the direction ρ of the next test position is calculated based on the gradient. k Then, through N s The total step size s that can be traversed in the sub-radiation power measurement adjustment k for

[0105] s k =s k,1 +(N s -1)s k,2 +max(N s -2,0)s k,3 .

[0106] 6. As attached Figure 5 As shown, after multiple iterations, until any one of the following termination conditions is met: (1) the number of iterations reaches the set maximum number; (2) the result of three consecutive iterations is x. k =x k+1 After the iteration terminates, the output is the beam peak position x that the algorithm converges to. peak .

[0107] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A gradient-based beam peak search method, characterized in that, include: First, fix the device under test (DUT) on the turntable and position its geometric center at the center of the test area. Using the geometric center of the DUT as the origin of the spherical coordinate system and the distance between the signal receiving device and the DUT as the radial distance of the spherical coordinate system, set the test intervals in the elevation and azimuth dimensions of the spherical coordinate system according to the half-power bandwidth of the electric and magnetic surfaces of the antenna in the DUT, thus forming a test grid with the azimuth and elevation angles as coordinates at a fixed radial distance. Based on the angular position indicated by each grid point in the test grid, the turntable is used to control the orientation of the device under test. After traversing the angles indicated by the test grid and measuring the radiation power at the angle indicated by each grid point in the test grid, the test grid is interpolated using the interpolation method to estimate the complete radiation pattern within the test area. Next, the locations of local maxima are obtained from the estimated complete radiation pattern, and these locations are used as the center of the secondary measurement region. Around the center of each secondary measurement region, multiple locations of secondary measurements are determined at a distance smaller than the grid spacing within the test grid, and the set of radiated power is measured at these locations. Finally, the maximum radiant power is obtained from the set of radiant powers measured in the second measurement. The position corresponding to the maximum radiant power in the second measurement is used as the initial position. The test position is updated each time according to the gradient search algorithm. When the gradient search algorithm converges to a certain position and does not change, the position and the magnitude of the radiant power measured at that position are output.

2. The gradient-based beam peak search method according to claim 1, characterized in that, Around the center of each secondary measurement region, including the orthogonal direction and the diagonal direction of the center of each secondary measurement region.

3. The gradient-based beam peak search method according to claim 1, characterized in that, The specific steps are as follows: Step 1: In a spherical coordinate system with the geometric center of the device under test as the origin. In the equation, the pitch angle θ ranges from -90° to θ to 90°, and the azimuth angle... Within the range r is the radial distance; within the range of elevation angle variation, it is the half-power beamwidth θ of the antenna in the device under test on the θ plane. 3dB N angles are selected at intervals, and within the range of horizontal angle variation, the antenna under test is used in... Half-power beamwidth on the surface M angles are selected at intervals to form a test grid with dimensions N×M; the orientation of the device under test is changed by a turntable. n = 1...N, m = 1...M, θ n For the selected nth pitch angle, To select the m-th horizontal angle, a signal receiving device is used to... Radiated power measured at [location] Receive; Step 2: Interpolate the test grid using interpolation to obtain the complete interpolated radiation pattern. This radiation pattern contains V local maxima, which are the center points of the secondary measurement area. Record the position of the v-th local maxima as... v = 1...V, θ v Let v be the pitch angle corresponding to the location of the v-th local maximum point. Let E(x) be the horizontal angle corresponding to the location of the v-th local maximum point. Record the radiated power of these local maximum points as E(x). v ); Step 3, at the v-th local maximum point At that point, with Δθ=θ n+1 -θ n , For interval, θ n+1 To test the θ value corresponding to the (n+1)th row of the grid, Δθ is the difference between the θ value corresponding to the (n+1)th row and the θ value corresponding to the nth row. For the (m+1)th row The value corresponding to the m-th row The difference in value For the test grid row (m+1) corresponding to Value, in Radiation power was measured again at q' positions along the orthogonal and diagonal directions. The radiation power measured at each of the q positions was denoted as . q = 1, 2, ..., q′; The radiation power E(x) measured in step 2 v ) and the measured in step 3 Merge into a set E v To obtain the location of the maximum radiated power in the set. θ ini The pitch angle corresponding to the location of the maximum value in the set. The horizontal angle corresponding to the position of the maximum value in the set; Step 4, with x ini Using the measured radiated power at that location as the starting point for gradient search, the gradient g(x) at the current location is calculated. ini ); Step 5: Suppose that determining the peak position requires K position updates. At the k-th test position... At, θ k Let be the pitch angle at the k-th test position. Let g(x) be the horizontal angle at the k-th test position, based on the gradient g(x) at the k-th test position. k Solving for the search direction ρ from the k-th test position to the (k+1)-th test position required to update the position yields the desired update location. k And search step size s k Find the (k+1)th test position. for x k+1 =x k +s k r k ; Where, θ k+1 Let the pitch angle be the (k+1)th test position. The horizontal angle at the (k+1)th test position; Step 6: Set the maximum number of iterations Max_iter, and repeat step 5 until either of the following termination conditions is met: (1) the number of iterations reaches Max_iter; (2) the result of three consecutive iterations is x. k+1 =x k ; The output after iteration terminates is the position x of the converged beam peak. peak and the corresponding radiated power E(x) peak ).

4. The gradient-based beam peak search method according to claim 1, characterized in that, q' is 8.

5. The gradient-based beam peak search method according to claim 3, characterized in that, g(x k The calculation formula for ) is as follows: Wherein, Δg θ and These represent the directions along the pitch angle θ and the horizontal angle in the spherical coordinate system, respectively. The change in direction for The magnitude of the radiated power at that location, for The magnitude of the radiated power at that location, for The magnitude of the radiated power at that location.

6. The gradient-based beam peak search method according to claim 3, characterized in that, ρ k The calculation formula is as follows: Where |·| represents g(x) k ) of the model.

7. The gradient-based beam peak search method according to claim 3, characterized in that, s k Including s k,1 s k,2 and s k,3 s k,1 s k,2 and s k,3 The calculation formula is as follows: Based on the current k-th position x k and the search direction ρ from the k-th position to the (k+1)-th position k Based on the sufficient descent condition, set the initial step size s. k,1 for s k,1 Substituting into the position update formula, we obtain the (k+1)th position x calculated in the first iteration. k+1,1 Compare x k+1,1 Radiated power E(x) at the location k+1,1 ) and x k Radiated power E(x) at the location k If E(x) k+1,1 )>E(x k If ρ increases, then ρ will increase. k Step size in direction; Let ξ(s k ) = E(x k + s k ρ k ), where E(x k + s k ρ k ) is the radiation power at x k + s k ρ k ), and ξ(s k ) is the radiation power with the step size as the independent variable in the direction of ρ k at x k . Then the quadratic step size s k,2 is Where ξ(0) is s k When x is 0, that is, x k The radiation power at x, ξ′(0) is x k Discrete derivative of the radiated power at point ξ(s) k,1 ) is x k+1,1 Radiated power at x; k+1,1 At this location, s k,2 Substituting into the position update formula, we obtain the (k+1)th position x calculated in the second iteration. k+1,2 ; If E(x) k+1,2 )>E(x k+1,1 ), E(x) k+1,2 ) is x k+1,2 Radiated power at point E(x) k+1,1 ) is x k+1,1 The radiated power at that point is expressed in cubic steps s. k,3 Increase ρ k Let A and B represent complex polynomials, and s be the step size in the direction. k,3 The calculation formula is as follows: The formulas for calculating A and B are as follows: Where, ξ(s) k,2 ) is x k +s k,2 ρ k The radiation power at that location.

8. The gradient-based beam peak search method according to claim 7, characterized in that, At position k, x k At that point, the search direction ρ required to update the position is calculated based on the gradient. k Then, through N s Secondary radiation power measurement adjusts the search step size s k The calculation formula is s k =s k,1 +(N s -1)s k,2 +max(N s -2,0)s k,3 .

9. A gradient-based beam peak search device, characterized in that, include: The device under test (DUT) and the turntable are used. The DUT is fixed on the turntable, and the geometric center of the DUT is located at the center of the test area. The test grid forming module is used to form a test grid with the geometric center of the device under test as the origin of the spherical coordinate system, the distance between the signal receiving device and the device under test as the radial distance of the spherical coordinate system, and the test intervals set according to the half-power bandwidth of the electric and magnetic surfaces of the antenna in the device under test in the elevation and azimuth dimensions of the spherical coordinate system, thereby forming a test grid with azimuth and elevation angles as coordinates at a fixed radial distance. The estimation module is used to control the orientation of the device under test by using a turntable to traverse the angles indicated by each grid point in the test grid, measure the radiation power at the angle indicated by each grid point in the test grid, and then estimate the complete radiation pattern in the test area by interpolating the test grid using an interpolation method. The secondary measurement module is used to obtain the locations of local maxima from the estimated complete radiation pattern, and use the locations of these local maxima as the center locations of the secondary measurement regions. Around the center location of each secondary measurement region, multiple secondary measurement locations are determined at a distance smaller than the grid spacing within the test grid, and the set of radiated power is measured at these secondary measurement locations. The location search module is used to obtain the maximum radiation power from the set of radiation power measured in the second measurement. The position corresponding to the maximum radiation power in the second measurement is used as the initial position. The test position is updated each time according to the gradient search algorithm. When the gradient search algorithm converges to a certain position and does not change, the position and the radiation power measured at that position are output.

10. A gradient-based beam peak search device according to claim 9, characterized in that, The turntable is controlled by software to rotate to an orientation consisting of horizontal and pitch angles with a resolution of 1°.

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