Antenna positioning method and antenna testing system

Abstract

The application provides an antenna positioning method and an antenna testing system. In the method, calibration compensation values between test probes obtained by a time difference of arrival method are used to calibrate and compensate test pseudo ranges between the test probes at different test points and an antenna to be tested, so that the calibration compensated test pseudo ranges between the test probes at the different test points and the antenna to be tested are obtained. Then, the position of the antenna to be tested is calculated according to the calibration compensated test pseudo ranges. The accuracy of the finally calculated position information of the antenna to be tested is good, that is, the antenna to be tested can be accurately positioned.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to a method for locating an antenna under test and an antenna testing system. Background Technology

[0002] In wireless communication and radar systems, the radiation characteristics of an antenna (e.g., radiation pattern, gain, polarization characteristics, etc.) are core parameters determining system performance. For antenna performance testing of large wireless devices (e.g., vehicles, aircraft, satellites, etc.), the large physical size of the device under test (DUT) makes it difficult to meet the Fresnel distance conditions required for far-field testing (typically...). Where D is the maximum size of the antenna. Since the wavelength is the operating wavelength, near-field testing technology is commonly used.

[0003] Near-field testing, by acquiring electromagnetic field amplitude and phase data in the near-field radiation region and combining it with rigorous near-far field transformation algorithms (such as plane spectrum expansion or mode expansion methods), can reconstruct the far-field radiation characteristics of the antenna, significantly reducing the requirement for testing distance.

[0004] Existing near-field testing systems are typically based on mechanical scanning architectures or fixed probe array architectures. Mechanical scanning systems acquire near-field data by moving the probe across a predetermined sampling surface using a high-precision positioning device, and the sampling density must satisfy the Nyquist space sampling theorem. However, for large devices under test, such as those mounted on vehicles or aircraft, it is difficult to achieve a strictly rigid coupling between the mounting base and the testing system. Alternatively, if the antenna under test is installed inside the device under test, it is difficult to directly obtain accurate position information.

[0005] The above situation will result in an unknown offset between the actual position of the antenna under test and the coordinate system of the test system. This unknown offset will introduce positioning error of the test probe, disrupt the mapping relationship between near-field data and spatial coordinates, and thus lead to mismatch of the phase term of the Green's function in the near-field transformation, ultimately causing pattern reconstruction error, typically manifested as sidelobe level rise, beam pointing deviation, or inaccurate zero-value depth measurement.

[0006] In summary, how to accurately locate the antenna under test has become an urgent technical problem to be solved. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a method for locating an antenna under test and an antenna testing system, so as to alleviate the technical problem that traditional technologies cannot accurately locate the antenna under test.

[0008] In a first aspect, embodiments of the present invention provide a method for locating an antenna under test, the method comprising: The device under test (DUT) with the antenna under test (UUT) is placed in an antenna testing system. Positioning tests are performed at multiple test points using the test probes of the antenna testing system. The time delay between each test probe and the UUT at different test points is obtained, and the pseudorange between each test probe and the UUT at different test points is calculated based on the time delay. Based on the calibration compensation values ​​between the test probes obtained by the time difference of arrival method, the test pseudorange between each test probe and the antenna under test at different test points is calibrated and compensated, thereby obtaining the calibrated and compensated test pseudorange between each test probe and the antenna under test at different test points. The position information of the antenna under test is calculated based on the calibrated and compensated pseudorange between each test probe and the antenna under test at different test points and the position information of the test points.

[0009] Furthermore, positioning tests are performed at multiple test points using the test probes of the antenna testing system, including: The device under test (DUT) is placed on the turntable of the antenna testing system. The turntable rotates the DUT, and positioning tests are performed using multiple fixed test probes at different turntable rotation angles; or... The probe scanning frame moves one or more of the test probes, performing positioning tests at different probe movement positions; or... The device under test (DUT) is placed on the turntable of the antenna test system. The turntable drives the DUT to rotate, and the probe scanning frame drives one or more test probes to move. Positioning tests are performed at different turntable rotation angles and test probe movement positions.

[0010] Furthermore, during the positioning test, the antenna under test and the test probe are connected to a test instrument, and the time delay between each test probe and the antenna under test at different test points is measured by the test instrument.

[0011] Furthermore, the calibration compensation values ​​between the test probes obtained based on the time difference of arrival method include: Place the calibration antenna in the antenna test system; The calibration antenna and the test probe are connected to a test instrument, and the time delay between the calibration antenna and each of the test probes is measured by the test instrument. The calibration pseudorange between the calibration antenna and each of the test probes is calculated based on the time delay between the calibration antenna and each of the test probes; A reference test probe is determined among the test probes, and the difference between the calibration pseudorange corresponding to each of the other test probes and the calibration pseudorange corresponding to the reference test probe is calculated to obtain the calibration pseudorange difference. Calculate the difference between the distance from each of the other test probes to the calibration antenna and the distance from the reference test probe to the calibration antenna to obtain the distance difference; The calibration compensation value between the reference test probe and the other test probes is calculated based on the calibration pseudorange difference and the distance difference.

[0012] Furthermore, if the number of test probes is one, the method includes: The device under test (DUT) with the antenna under test is placed in the antenna test system. Positioning tests are performed at multiple test points using the test probe of the antenna test system. The time delay between the test probe and the antenna under test at different test points is obtained, and the pseudorange between the test probe and the antenna under test at different test points is calculated based on the time delay. The position information of the antenna under test is calculated based on the test pseudorange between the test probe and the antenna under test at different test points and the position information of the test points.

[0013] Furthermore, the calculation employs fitting algorithms, including: least squares method, Newton's method, and gradient descent method.

[0014] Furthermore, if the fitting algorithm is the least squares method, the objective function of the least squares method is: A rectangular coordinate system is established with the center of the antenna test system as the origin and the device under test as the reference system. Indicates the first i The calibration-compensated pseudorange for each test point Indicates the first i The coordinates of the test points This indicates the coordinates of the antenna under test. Indicates the first i The spatial distance between each test point and the antenna under test Indicates the first i The calibration-compensated test pseudorange corresponding to the test point minus the first test point i The spatial distance between each test point and the antenna under test, and the parameters to be fitted are: .

[0015] Furthermore, different weights are used for fitting calculations at different test points, and the weights are positively correlated with the received signal power of the test point.

[0016] Furthermore, the method also includes: Randomly select a preset number of target test points and the calibration-compensated test pseudoranges corresponding to the target test points from the coordinates of all test points; Based on the coordinates of the target test point and the calibrated and compensated pseudorange corresponding to the target test point, a fitting algorithm is used to fit and calculate the position information of the antenna under test to obtain the target position. Calculate the spatial distance based on the target location and the location information of the test probe; The spatial distance for testing is calculated based on the pseudorange between each test probe and the antenna under test at different test points and the influence of link differences between different test probes. Calculate the error of each target test point based on the spatial distance and the test spatial distance; Target test points with errors less than a preset threshold are designated as interior points, and the number of interior points is counted. Repeat the above steps, select the target test point with the most inner points as the optimal target test point, and obtain the position information of the antenna under test calculated based on the optimal target test point.

[0017] In a second aspect, embodiments of the present invention also provide an antenna testing system, which is used to perform the antenna under test positioning method described in any of the first aspects above. The antenna testing system includes: an anechoic chamber, a test probe, a test instrument, and a pose adjustment mechanism. The anechoic chamber is used to provide a testing environment; The test instrument is used for signal generation or signal analysis; The mechanical positioning system is used as a pose adjustment mechanism to change the pose of the antenna under test, and / or change the pose of the test probe.

[0018] In this embodiment of the invention, a method for locating an antenna under test (ATT) is provided, comprising: placing the ADT with the ADT in an antenna testing system; performing positioning tests at multiple test points using test probes of the antenna testing system to obtain the time delay between each test probe and the ADT at different test points; calculating the pseudorange between each test probe and the ADT at different test points based on the time delay; calibrating and compensating the pseudorange between each test probe and the ADT at different test points based on the calibration compensation value obtained between each test probe using the time difference of arrival method, thereby obtaining the calibrated and compensated pseudorange between each test probe and the ADT at different test points; and calculating the position information of the ADT based on the calibrated and compensated pseudorange between each test probe and the ADT at different test points and the position information of the test points. As described above, in the antenna under test positioning method of the present invention, the test pseudorange between each test probe and the antenna under test at different test points is calibrated and compensated according to the calibration compensation value between each test probe obtained based on the time difference of arrival method, thereby obtaining the calibrated and compensated test pseudorange between each test probe and the antenna under test at different test points. Then, the position of the antenna under test is calculated based on the calibrated and compensated test pseudorange. The final calculated position information of the antenna under test has high accuracy. In other words, the antenna under test can be accurately positioned using the antenna test system's own device, alleviating the technical problem that traditional technology cannot accurately position the antenna under test. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 A flowchart of a method for locating an antenna under test provided in an embodiment of the present invention; Figure 2 A schematic diagram of a multi-probe spherical antenna scanning test system provided in an embodiment of the present invention; Figure 3 This is a schematic diagram showing different weights corresponding to different test points provided in the embodiments of the present invention. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In traditional antenna testing systems, there is an unknown offset between the actual position of the antenna under test (DUT) and the coordinate system of the measurement system. Existing indoor positioning technologies are difficult to apply to the positioning of DUTs. For example, GPS positioning technology requires the DUT to support the GPS frequency band, and GPS positioning relies on satellite signals, making it unusable in anechoic chambers. Deploying a dedicated GPS module and corresponding GPS antenna in an anechoic chamber would be too costly. UWB positioning technology also requires the DUT to support the UWB protocol and frequency band, limiting its versatility. RSSI-based positioning technology is susceptible to antenna pattern variations and multipath effects, resulting in significant positioning errors that fail to meet antenna testing requirements. Cellular base station positioning technology has very low accuracy and is unsuitable for indoor scenarios. Therefore, traditional technologies cannot accurately locate the DUT.

[0023] Based on this, in the antenna under test positioning method of the present invention, the test pseudorange between each test probe and the antenna under test at different test points is calibrated and compensated according to the calibration compensation value between each test probe obtained based on the time difference of arrival method, thereby obtaining the calibrated and compensated test pseudorange between each test probe and the antenna under test at different test points. Then, the position of the antenna under test is calculated based on the calibrated and compensated test pseudorange. The final calculated position information of the antenna under test has high accuracy. In other words, the antenna under test can be accurately positioned using the device of the antenna test system itself.

[0024] To facilitate understanding of this embodiment, a method for locating an antenna under test disclosed in this embodiment of the invention will first be described in detail.

[0025] Example 1: According to an embodiment of the present invention, an embodiment of a method for locating an antenna under test is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0026] Figure 1 This is a flowchart of a method for locating an antenna under test according to an embodiment of the present invention, such as... Figure 1 As shown, the method includes the following steps: Step S102: Place the device under test with the antenna under test in the antenna test system, perform positioning tests at multiple test points through the test probes of the antenna test system, obtain the time delay between each test probe and the antenna under test at different test points, and calculate the test pseudorange between each test probe and the antenna under test at different test points based on the time delay. Specifically, this invention utilizes the hardware of the antenna testing system itself, combined with the time difference of arrival (TDOA) method, to locate the antenna under test (AUT). The aforementioned antenna testing system is used to test the radiation characteristics (such as radiation pattern, gain, polarization, etc.) of the AUT in a wireless device. It includes: an anechoic chamber to provide the testing environment; one or more test probes; test instruments for signal generation or analysis; and a pose adjustment mechanism to enable the test probes to scan the AUT (Antenna under Test) at different angles. The pose adjustment mechanism is used to change the pose of the DUT (Device under Test), thereby changing the pose of the AUT, or / and to change the pose of the test probes. Here, pose refers to position and orientation / direction. The pose adjustment mechanism can specifically be: an azimuth turntable, a pitch turntable, a multi-degree-of-freedom robotic arm, a probe scanning frame, etc.

[0027] like Figure 2 As shown, the technical solution of the present invention will be described using a multi-probe spherical antenna test system as an example. The test system shown in the figure includes: an anechoic chamber; multiple test probes (arranged at certain angular intervals on a vertical arc-shaped path and capable of moving along the arc-shaped path); a test instrument (vector network analyzer, not shown in the figure); an azimuth turntable (carrying the DUT and driving it to rotate in the horizontal direction); and a probe scanning frame (installing the test probes and driving them to move along the aforementioned arc-shaped path).

[0028] Step S104: Based on the calibration compensation values ​​between each test probe obtained by the time difference of arrival method, the test pseudorange between each test probe and the antenna under test at different test points is calibrated and compensated, thereby obtaining the calibrated and compensated test pseudorange between each test probe and the antenna under test at different test points.

[0029] The principles of calibration will be explained in detail below.

[0030] It is understandable that if the RF link of the test probe is replaced, the calibration compensation value needs to be re-acquired.

[0031] Step S106: Based on the calibrated and compensated pseudorange of each test probe at different test points and the position information of the test points, the position information of the antenna under test is calculated.

[0032] Specifically, in related technologies, the position information of the test points can be obtained through the system's built-in mechanical positioning system, such as a test workpiece orientation turntable (with rotation axes of azimuth, pitch, or polarization), a multi-degree-of-freedom robotic arm, or a test probe scanning frame (rocker arm or slide rail). These mechanical positioning systems are equipped with origin / zero point sensors and position detection sensors (such as encoders, grating rulers, and laser trackers) or visual positioning devices, which can calculate and output the three-dimensional coordinates of the test points through feedback signals. Alternatively, the position information of multiple test points can be pre-set, and the motion controller can calculate the angle / distance that the mechanical positioning system needs to move based on this position information, and drive the motor to accurately reach that position.

[0033] If multiple test probes with fixed settings are used for positioning, the position information of the test probes can also be directly used as the position information of the test point.

[0034] The specific calculation process will be described in detail below, and will not be repeated here.

[0035] In this embodiment of the invention, a method for locating an antenna under test (ATT) is provided, comprising: placing the ADT with the ADT in an antenna testing system; performing positioning tests at multiple test points using test probes of the antenna testing system to obtain the time delay between each test probe and the ADT at different test points; calculating the pseudorange between each test probe and the ADT at different test points based on the time delay; calibrating and compensating the pseudorange between each test probe and the ADT at different test points based on the calibration compensation value obtained between each test probe using the time difference of arrival method, thereby obtaining the calibrated and compensated pseudorange between each test probe and the ADT at different test points; and calculating the position information of the ADT based on the calibrated and compensated pseudorange between each test probe and the ADT at different test points and the position information of the test points. As described above, in the antenna under test positioning method of the present invention, the test pseudorange between each test probe and the antenna under test at different test points is calibrated and compensated according to the calibration compensation value between each test probe obtained based on the time difference of arrival method, thereby obtaining the calibrated and compensated test pseudorange between each test probe and the antenna under test at different test points. Then, the position of the antenna under test is calculated based on the calibrated and compensated test pseudorange. The final calculated position information of the antenna under test has high accuracy. In other words, the antenna under test can be accurately positioned using the antenna test system's own device, alleviating the technical problem that traditional technology cannot accurately position the antenna under test.

[0036] The above provides a brief overview of the antenna positioning method of the present invention. The specific details involved are described in detail below.

[0037] In an optional embodiment of the present invention, the plurality of test points includes at least four non-coplanar test points.

[0038] In an optional embodiment of the present invention, positioning tests are performed at multiple test points using the test probes of the antenna testing system, specifically including the following steps: (1) Place the device under test (DUT) on the turntable of the antenna test system. The turntable rotates the DUT. At different turntable rotation angles, position tests are performed using multiple fixed test probes; or, (2) The probe scanning frame moves one or more test probes to perform positioning tests at different test probe positions; or, (3) Place the device under test on the turntable of the antenna test system. The turntable drives the device under test to rotate, and the probe scanning frame drives one or more test probes to move. Positioning tests are performed at different turntable rotation angles and test probe movement positions.

[0039] Specifically, the device under test can be placed at the center of the antenna test system, but it is not necessary to place it at the center, as long as it is within the quiet zone.

[0040] In an optional embodiment of the present invention, during the positioning test, the antenna under test and the test probe are connected to a test instrument (it should be noted that the transceiver is not limited in this positioning test), and the time delay between each test probe and the antenna under test at different test points is measured by the test instrument.

[0041] Specifically, the following examples illustrate different test points: The antenna test system includes N test probes (or more, but only N are used). The turntable rotates one revolution in 30° steps, and the time delay is tested at each step. Therefore, a total of [number] probes are uniformly distributed in the spherical space. The test data (i.e., delay data) of 12 test points (360° / 30°=12, the test points are determined by the test angle of the antenna under test and the position of the test probe, one test point corresponds to one test angle of the antenna under test and one position of the test probe).

[0042] It should be noted that the test probe at the 0° theta position is not considered here, because the test probe at this position remains in the same spatial position on the test sphere throughout the turntable rotation. During this positioning test, it should be ensured that the RF link of the test probe is consistent with the RF link of the test probe when the calibration compensation value is obtained.

[0043] In an optional embodiment of the present invention, the calibration compensation value between the test probes obtained based on the time difference of arrival method specifically includes the following steps: (1) Place the calibration antenna at the center of the antenna test system; Specifically, the calibration antenna can be placed at the center of the antenna test system, with the center of the antenna test system being the origin of the spherical coordinate system. For multi-probe antenna test systems, the distances of different test probes from the center of the antenna test system are equal, making the calculation simple by placing the calibration antenna at the center. In fact, even if it is not placed at the center, as long as the position of the calibration antenna is known, the distance between the calibration antenna and the test probes can be calculated, thus not affecting the calibration.

[0044] The calibration antenna can be any antenna. For multi-probe antenna testing systems, an omnidirectional antenna can be used. The advantage of using an omnidirectional antenna is that its phase center is relatively stable in all directions, thus allowing calibration of all test probes without rotating the calibration antenna. If other antennas are used as calibration antennas, the calibration antenna and test probes need to be aligned during signal propagation to reduce errors.

[0045] (2) Connect the calibration antenna and test probe to the test instrument, and measure the time delay between the calibration antenna and each test probe through the test instrument; Specifically, the calibration antenna and test probe are connected to the receiver and transmitter of the test instrument, respectively (it should be noted that the receiver and transmitter are not limited in this calibration test). The calibration antenna and the test probe are measured by the test instrument. i Time delay between test probes That is, when using the first i The time it takes for the test instrument to receive a signal from the time the test probe transmits or receives a signal.

[0046] Delay can be obtained by reading group delay measurement data from a vector network analyzer (a type of test instrument). This group delay measurement data is the delay itself; signals of different frequencies will have different phase changes when propagating the same distance. When the propagation time is the same, the magnitude of the phase change is proportional to the frequency. Based on this principle, group delay is defined. ,Right now When the frequency interval is sufficiently small, the network divider directly calculates the ratio of the phase difference to the frequency difference between adjacent frequency points, which is the group delay. Therefore, the delay data can be obtained by reading the group delay data of the network divider. Alternatively, if the test instrument is a time domain reflectometer (TDR), the total link delay can be determined by sending a pulse signal and measuring the signal round-trip time.

[0047] In addition to using test instruments with group delay testing capabilities (such as network analyzers) to detect delay, FMCW wave radar or other test instruments that can emit FMCW waves can also be used, as well as GNSS modules, etc.

[0048] (3) The calibration pseudorange between the calibration antenna and each test probe is calculated based on the time delay between the calibration antenna and each test probe; Specifically, based on the calibration antenna and the first i Time delay between test probes Calculate the calibration antenna and the first i Calibration pseudorange between test probes , .

[0049] Here, we explain pseudorange: Theoretically, electromagnetic waves travel at the speed of light in space. Propagation, the time delay of propagation (latency). Spatial distance of propagation It should be a linear relationship. However, the delay obtained through actual testing with testing instruments... It includes not only the time it takes for electromagnetic waves to propagate in space, but also the time it takes for them to travel through the radio frequency link. Therefore, it will be based on... Calculated distance Defined as pseudorange. Calibration pseudorange is the pseudorange obtained during calibration. Similarly, test pseudorange is the pseudorange obtained during positioning testing.

[0050] (4) Determine a reference test probe among the test probes, and calculate the difference between the calibration pseudorange corresponding to each of the other test probes and the calibration pseudorange corresponding to the reference test probe to obtain the calibration pseudorange difference. Specifically, the test probe with the shortest or most stable link can be selected as the reference test probe, and the calculation of the first... i The difference between the calibration pseudorange of each test probe and the calibration pseudorange of the reference test probe .

[0051] (5) Calculate the difference between the distance from each of the other test probes to the calibration antenna and the distance from the reference test probe to the calibration antenna, and obtain the distance difference; Specifically, the first i The difference between the distance from each test probe to the calibration antenna and the distance from the reference test probe to the calibration antenna is denoted as . .

[0052] (6) Calculate the calibration compensation value between the reference test probe and other test probes based on the calibration pseudorange difference and distance difference.

[0053] Specifically, the first i Calibration compensation value for each test probe = Finally, N-1 calibration compensation values ​​are obtained, where N is the number of test probes.

[0054] The physical meaning of the calibration compensation value is explained here. For multi-probe antenna testing systems, the purpose of calibration compensation is to eliminate the differences caused by the RF link delay of different test probes, ensuring the accuracy of positioning tests. This delay difference is mainly caused by differences in hardware paths (different group delay characteristics of devices such as cable lengths, connectors, amplifiers, and filters for different test probes) and environmental factors (temperature changes causing material expansion or electronic component parameter drift). (Refer to...) Figure 2 , Defined as an electromagnetic wave in the th... i The propagation distance of the electromagnetic wave in the RF link of the test probe is equal to the distance traveled by the electromagnetic wave on the 1st test probe. i The propagation time of the test probe in the RF link multiplied by the velocity. For ease of description, let's call it the 1st test probe. i The cable length of each test probe. Differences in RF link delay caused by different test probes will be reflected in the cable length between different test probes. The difference lies in the time delay corresponding to the calibration pseudorange. On the other hand, the time delay includes three parts: the propagation time of the electromagnetic wave in the RF link of the test probe, the propagation time of the electromagnetic wave in the space between the test probe and the calibration antenna, and the propagation time of the electromagnetic wave in the RF link of the calibration antenna. Correspondingly, the time delay between the calibration antenna and the... i Calibration pseudorange between test probes It also includes three parts: the first i The length of each test probe The length of the antenna under test (The propagation distance of an electromagnetic wave in the RF link of the antenna under test is equal to the propagation time of the electromagnetic wave in the RF link of the antenna under test multiplied by its speed), and the first... i The spatial distance between each test probe and the calibration antenna is denoted as . Once a reference test probe is determined, in calculating the... i Calibration compensation value of each test probe ( When ), the length of the antenna under test was removed. and the i Spatial distance between each test probe and the calibration antenna The effect of this, the calculated result of its calibration compensation value is equal to the first i The length of each test probe The difference in line length between the probe and the reference test probe. Therefore, by calibrating and compensating the pseudorange obtained from the positioning test based on this difference in line length, the positioning accuracy of the antenna under test can be improved.

[0055] It is understandable that electromagnetic waves propagate at different speeds in free space and in cables. However, the calibration compensation value is calculated based on the difference in cable length between different test probes and is a relative value. Therefore, the difference in propagation speed does not affect the accuracy of the calculation results. Thus, the difference in propagation speed of electromagnetic waves in different media does not need to be included in the above calculation.

[0056] It should be noted that for multi-probe spherical antenna test systems, when the calibration antenna is located at the center of the antenna test system, if the spatial distance from each test probe to the center of the antenna test system is equal, then calculation is not required. For example, the calibration pseudorange of test probe #1 is... The calibration pseudorange of test probe #2 is The distances from test probes 1 and 2 to the center of the antenna test system are equal. Taking test probe 1 as the reference, the calibration compensation value of test probe 2 is... .

[0057] If the antenna test system is a single-probe antenna test system, then the above calibration process is not required. That is, if the number of test probes is one, the method includes: (1) Place the device under test with the antenna under test in the antenna test system, perform positioning tests at multiple test points through the test probe of the antenna test system, obtain the time delay between the test probe and the antenna under test at different test points, and calculate the test pseudorange between the test probe and the antenna under test at different test points based on the time delay. (2) The position information of the antenna under test is calculated based on the test pseudorange between the test probe and the antenna under test at different test points and the position information of the test points.

[0058] It should be noted that this calculation process is the same as the calculation process in step S106 above, and can be referred to the relevant description below, which will not be repeated here.

[0059] In an optional embodiment of the present invention, the calculation employs a fitting algorithm, including: least squares method, Newton's method, and gradient descent method.

[0060] In an optional embodiment of the present invention, if the fitting algorithm is the least squares method, the objective function of the least squares method is: In this system, a rectangular coordinate system is established with the center of the antenna test system as the origin and the device under test as the reference system. Indicates the first i The calibration-compensated pseudorange for each test point Indicates the first i The coordinates of the test points Indicates the coordinates of the antenna under test. Indicates the first iThe spatial distance between each test point and the antenna under test Indicates the first i The calibration-compensated test pseudorange corresponding to the test point minus the first test point i The spatial distance between each test point and the antenna under test, and the distance between each test point. All are the same and constant, and the parameters to be fitted are: The fitted data are N represents the number of test points, and the objective function is the sum of squared residuals. The final calculation aims to obtain the coordinates of the antenna under test.

[0061] In an optional embodiment of the present invention, different test points are fitted with different weights, and the weights are positively correlated with the received signal power of the test points.

[0062] Specifically, to improve the accuracy of the calculated location information of the antenna under test (AUT), different weights are used for different test points during the fitting calculation. Since the gain of the AUT varies in different directions, the power of the received signal at different spatial locations (i.e., test points) differs during positioning testing. Different power signals have different signal-to-noise ratios (SNRs). Generally, a higher SNR results in higher testing accuracy. Therefore, test points with higher SNRs are assigned larger weights. A weighting function can be used to map the received signal power of the test points to the calculated weights. Specifically, a step function, exponential function, or a combination of multiple functions can be used. The weights are then multiplied by the residuals and used in the fitting calculation. (Refer to...) Figure 3 In one example, the test point has an SNR of 45. Test points with a weight of 1 and an SNR of 30 were used. The test points used had a weight of 0.6 and an SNR of 10. The weight used is 0.

[0063] In an optional embodiment of the present invention, the method further includes: (1) Randomly select a preset number of target test points and the corresponding calibration-compensated test pseudoranges from the coordinates of all test points; (2) Based on the coordinates of the target test point and the test pseudorange after calibration compensation corresponding to the target test point, the position information of the antenna under test is calculated by fitting algorithm to obtain the target position; (3) Calculate the spatial distance based on the target location and the position information of the test probe; (4) Calculate the test spatial distance based on the test pseudorange between each test probe and the antenna under test at different test points and the influence of the link difference between different test probes; (5) Calculate the error of each target test point based on the spatial distance and the test spatial distance; (6) Take the target test points with errors less than the preset threshold as interior points and count the number of interior points; (7) Repeat the above steps, select the target test point with the most internal points as the optimal target test point, and obtain the position information of the antenna under test calculated based on the optimal target test point.

[0064] Specifically, noise may exist in a large number of test points. Therefore, appropriate noise reduction algorithms from relevant technologies can be used to process the data and improve the accuracy of the fitting calculation. For example, the RANSAC (Random Sample Consensus) algorithm. The principle of RANSAC is to fit using a subset of data, and determine the best subset based on the number of inliers (errors within a threshold). In this algorithm, the dataset is the group delay data of all test points (assuming it is...). Select (number), A subset (or a smaller subset) of the target test points. The target position is obtained by fitting the subset data (i.e., the coordinates of a predetermined number of target test points and the corresponding calibrated and compensated pseudoranges). Based on the target location and the location information of the test probe Calculate its spatial distance Compare it with the spatial distance of the test. By comparing, we can obtain ( The error of each target test point is calculated. A preset threshold is defined, and the error is compared with this threshold. Target test points with errors less than the threshold are defined as inliers, and those with errors greater than the threshold are defined as outliers. Fitting calculations are performed on each subset (or a certain number of subsets), and the number of inliers is recorded. The core of the RANSAC algorithm is to judge the quality of a subset based on the number of inliers. Therefore, the subset with the most inliers is selected as the noise-free subset, and the target test points outside this subset are considered noise points.

[0065] The method of this invention is based on the Time Difference of Arrival (TDOA) positioning method. Utilizing the hardware of the antenna testing system itself, it can accurately locate the position of the antenna under test, thereby solving the problem of testing accuracy caused by the unknown offset between the actual position of the antenna under test and the coordinate system of the antenna testing system in existing technologies. This invention is highly versatile and can be used for antennas under test in different frequency bands without incurring additional hardware costs. Specifically, this invention ensures positioning accuracy through the following aspects: (1) utilizing the high-precision testing instruments of the antenna testing system itself; (2) eliminating the accuracy impact caused by link differences between different test probes through calibration testing; and (3) performing positioning tests at multiple spatial locations (i.e., test points) and reducing errors through algorithms. The final positioning accuracy of this invention can reach the centimeter or even millimeter level.

[0066] Example 2: According to an embodiment of the present invention, an antenna testing system is provided. The antenna testing system is used to perform the antenna under test positioning method in Embodiment 1 above. The antenna testing system includes: an anechoic chamber, a test probe, test instruments, and a pose adjustment mechanism. An anechoic chamber is used to provide a testing environment; Test instruments used for signal generation or signal analysis; The pose adjustment mechanism is used to change the pose of the antenna under test, and / or change the pose of the test probe.

[0067] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0068] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0069] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for locating an antenna under test, characterized in that, The method includes: The device under test (DUT) with the antenna under test (UUT) is placed in an antenna testing system. Positioning tests are performed at multiple test points using the test probes of the antenna testing system. The time delay between each test probe and the UUT at different test points is obtained, and the pseudorange between each test probe and the UUT at different test points is calculated based on the time delay. Based on the calibration compensation values ​​between the test probes obtained by the time difference of arrival method, the test pseudorange between each test probe and the antenna under test at different test points is calibrated and compensated, thereby obtaining the calibrated and compensated test pseudorange between each test probe and the antenna under test at different test points. The position information of the antenna under test is calculated based on the calibrated and compensated pseudorange between each test probe and the antenna under test at different test points and the position information of the test points.

2. The method according to claim 1, characterized in that, Positioning tests are performed at multiple test points using the test probes of the antenna testing system, including: The device under test (DUT) is placed on the turntable of the antenna testing system. The turntable rotates the DUT, and positioning tests are performed using multiple fixed test probes at different turntable rotation angles; or... The probe scanning frame moves one or more of the test probes, performing positioning tests at different probe movement positions; or... The device under test (DUT) is placed on the turntable of the antenna test system. The turntable drives the DUT to rotate, and the probe scanning frame drives one or more test probes to move. Positioning tests are performed at different turntable rotation angles and test probe movement positions.

3. The method according to claim 1 or 2, characterized in that, During positioning testing, the antenna under test and the test probe are connected to a test instrument, and the time delay between each test probe and the antenna under test at different test points is measured by the test instrument.

4. The method according to claim 1, characterized in that, The calibration compensation values ​​between the test probes, obtained based on the time difference of arrival method, include: Place the calibration antenna in the antenna test system; The calibration antenna and the test probe are connected to a test instrument, and the time delay between the calibration antenna and each of the test probes is measured by the test instrument. The calibration pseudorange between the calibration antenna and each of the test probes is calculated based on the time delay between the calibration antenna and each of the test probes; A reference test probe is determined among the test probes, and the difference between the calibration pseudorange corresponding to each of the other test probes and the calibration pseudorange corresponding to the reference test probe is calculated to obtain the calibration pseudorange difference. Calculate the difference between the distance from each of the other test probes to the calibration antenna and the distance from the reference test probe to the calibration antenna to obtain the distance difference; The calibration compensation value between the reference test probe and the other test probes is calculated based on the calibration pseudorange difference and the distance difference.

5. The method according to claim 1, characterized in that, If the number of test probes is one, the method includes: The device under test (DUT) with the antenna under test is placed in the antenna test system. Positioning tests are performed at multiple test points using the test probe of the antenna test system. The time delay between the test probe and the antenna under test at different test points is obtained, and the pseudorange between the test probe and the antenna under test at different test points is calculated based on the time delay. The position information of the antenna under test is calculated based on the test pseudorange between the test probe and the antenna under test at different test points and the position information of the test points.

6. The method according to claim 1, characterized in that, The calculation employs fitting algorithms, including: least squares method, Newton's method, and gradient descent method.

7. The method according to claim 6, characterized in that, If the fitting algorithm is the least squares method, the objective function of the least squares method is: A rectangular coordinate system is established with the center of the antenna test system as the origin and the device under test as the reference system. Indicates the first i The calibration-compensated pseudorange for each test point Indicates the first i The coordinates of the test points This indicates the coordinates of the antenna under test. Indicates the first i The spatial distance between each test point and the antenna under test Indicates the first i The calibration-compensated test pseudorange corresponding to the test point minus the first test point i The spatial distance between each test point and the antenna under test, and the parameters to be fitted are: .

8. The method according to claim 7, characterized in that, Different test points are fitted with different weights, and the weights are positively correlated with the received signal power of the test point.

9. The method according to claim 7, characterized in that, The method further includes: Randomly select a preset number of target test points and the calibration-compensated test pseudoranges corresponding to the target test points from the coordinates of all test points; Based on the coordinates of the target test point and the calibrated and compensated pseudorange corresponding to the target test point, a fitting algorithm is used to fit and calculate the position information of the antenna under test to obtain the target position. Calculate the spatial distance based on the target location and the location information of the test probe; The spatial distance for testing is calculated based on the pseudorange between each test probe and the antenna under test at different test points and the influence of link differences between different test probes. Calculate the error of each target test point based on the spatial distance and the test spatial distance; Target test points with errors less than a preset threshold are designated as interior points, and the number of interior points is counted. Repeat the above steps, select the target test point with the most inner points as the optimal target test point, and obtain the position information of the antenna under test calculated based on the optimal target test point.

10. An antenna testing system, characterized in that, The antenna testing system is used to perform the antenna positioning method according to any one of claims 1 to 9. The antenna testing system includes: an anechoic chamber, a test probe, test instruments, and a pose adjustment mechanism. The anechoic chamber is used to provide a testing environment; The test instrument is used for signal generation or signal analysis; The pose adjustment mechanism is used to change the pose of the antenna under test, and / or change the pose of the test probe.

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