Array antenna calibration method, device and storage medium

Abstract

The present application discloses a calibration method, device and storage medium for an array antenna. In the present application, an array response matrix is ​​constructed based on the position of the array antenna under test relative to the detection antenna, and the antenna pattern of the array antenna under test is tested to obtain the antenna pattern data vector, and then an amplitude-phase error that can reflect both the coupling relationship and the channel amplitude-phase error is obtained based on the array response matrix and the antenna pattern data, and the convergence of the amplitude-phase error is monitored, and finally the target calibration weights applicable to the array antenna are determined according to the amplitude-phase error that meets the convergence condition obtained from two adjacent calibration tests, so that the calibration and decoupling of the array antenna to be calibrated can be realized without adding any hardware equipment to the array antenna to be calibrated, and the accuracy of the calibration result is effectively guaranteed.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of communications, and in particular to a calibration method, device and storage medium for an array antenna. Background Art

[0002] With the increasing maturity of large-scale multi-antenna technology and its widespread application in base station systems, people have higher requirements for the amplitude and phase consistency between the arrays in the base station array antenna. If there is a large amplitude and phase inconsistency between the arrays in the base station array antenna, the beamforming and multiple input multiple output (MIMO) of the array antenna will fail, thus affecting the performance of the base station system. Through analysis, it is found that there are two main factors that affect the amplitude and phase inconsistency between the arrays in the base station array antenna. One is the amplitude and phase difference between the corresponding channels of each array, and the other is the coupling between the arrays.

[0003] However, the current calibration schemes for array antennas are basically based on the amplitude and phase errors obtained by calculating the radiation pattern corresponding to the test array antenna to calibrate the array antenna, which is not suitable for situations where coupling exists, that is, for array antennas with coupling, such as millimeter wave array antennas, terahertz array antennas, optical band array antennas, conformal array antennas, sparse array antennas, and various 5G and 6G base station products that use similar array antennas. The current calibration schemes for array antennas will cause large errors in the calibration results due to coupling factors, and therefore cannot meet the higher precision calibration requirements for array antennas. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a calibration method, device and storage medium for an array antenna, aiming to solve the above-mentioned technical problems.

[0005] To solve the above technical problems, an embodiment of the present application provides a calibration method for an array antenna, comprising:

[0006] Constructing an array response matrix of the array antenna under test relative to the detection antenna;

[0007] Testing the antenna pattern of the array antenna under test to obtain the antenna pattern data vector;

[0008] Calculating the coupled channel amplitude and phase errors of each array element in the measured array antenna according to the array response matrix and the antenna pattern data vector to obtain the amplitude and phase errors of each array element in the measured array antenna;

[0009] When the amplitude and phase errors obtained from two adjacent calibration tests meet a preset convergence condition, the test is terminated, and a target calibration weight is determined according to the amplitude and phase errors obtained from two adjacent calibration tests;

[0010] The array antenna to be calibrated is calibrated according to the target calibration weight.

[0011] To achieve the above-mentioned purpose, the embodiment of the present application further provides a calibration device for an array antenna, comprising: a target calibration weight determination module and an array antenna calibration module;

[0012] The target calibration weight determination module is used to construct an array response matrix of the array antenna under test relative to the detection antenna;

[0013] The target calibration weight determination module is also used to test the antenna pattern of the array antenna under test and obtain the antenna pattern data vector;

[0014] The target calibration weight determination module is further used to calculate the coupled channel amplitude and phase error of each array element in the measured array antenna according to the array response matrix and the antenna pattern data vector, so as to obtain the amplitude and phase error of each array element in the measured array antenna;

[0015] The target calibration weight determination module is further used to end the test when the amplitude and phase errors obtained from two adjacent calibration tests meet a preset convergence condition, and determine the target calibration weight according to the amplitude and phase errors obtained from two adjacent calibration tests;

[0016] The array antenna calibration module is used to calibrate the array antenna to be calibrated according to the target calibration weight.

[0017] To achieve the above object, an embodiment of the present application further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the above-mentioned array antenna calibration method is implemented.

[0018] The array antenna calibration method, device and storage medium proposed in the present application construct an array response matrix relative to a detection antenna based on the array antenna under test, and test the antenna pattern of the array antenna under test, thereby obtaining antenna pattern data that can reflect the channel amplitude and phase errors corresponding to each array element in the array antenna. Then, based on the array response matrix and the antenna pattern data, an amplitude and phase error that can reflect both the coupling relationship and the channel amplitude and phase error is obtained, and by monitoring the convergence of the amplitude and phase error, finally a target calibration weight suitable for the array antenna is determined based on the amplitude and phase errors that meet the convergence conditions obtained from two adjacent calibration tests, so that the array antenna to be calibrated can be calibrated according to the target calibration weight, without adding any hardware equipment to the array antenna to be calibrated.

[0019] In addition, since the target calibration weight is determined based on the amplitude-phase error that can reflect the coupling relationship and the channel amplitude-phase error, the antenna to be calibrated can also be decoupled during the calibration process of the array antenna to be calibrated according to the target calibration weight.

[0020] In addition, since the target calibration weights are determined based on the amplitude and phase errors that meet the convergence conditions, that is, the target calibration weights used to calibrate the array antenna to be calibrated are obtained through iterative training, it is ensured that the target calibration weights can be better applied to the array antenna to be calibrated, thereby meeting the higher precision calibration requirements for the array antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] One or more embodiments are exemplarily described by the pictures in the corresponding drawings, and these exemplary descriptions do not constitute limitations on the embodiments.

[0022] Figure 1 is a flow chart of a calibration method for an array antenna provided in the first embodiment of the present application;

[0023] Figure 2 is a schematic diagram of an indoor far-field calibration environment applicable to the array antenna calibration method provided in the first embodiment of the present application;

[0024] Figure 3 is a schematic diagram of a planar near-field calibration environment applicable to the calibration method for the array antenna provided in the first embodiment of the present application;

[0025] Figure 4 is a schematic diagram of a compact field calibration environment applicable to the array antenna calibration method provided in the first embodiment of the present application;

[0026] Figure 5 When the array antenna calibration method provided in the first embodiment of the present application is used to calibrate the downlink channel signal, the signal flow between the detected array antenna 200, the detection antenna 300 and the beam controller 500;

[0027] Figure 6 The signal flow direction between the detected array antenna 200, the detection antenna 300 and the beam controller 500 when the array antenna calibration method provided in the first embodiment of the present application is calibrated for the uplink channel signal;

[0028] Figure 7 is a flow chart of a calibration method for an array antenna provided in a second embodiment of the present application;

[0029] Figure 8 It is a schematic diagram of calibrating the forward signal based on the beamforming weight and the target calibration weight in step S50 of the array antenna calibration method provided in the second embodiment of the present application;

[0030] Fig. 9 This is the array antenna calibration device provided in the third embodiment of the present application. DETAILED DESCRIPTION

[0031] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. However, it will be appreciated by those skilled in the art that in the present application, many technical details are proposed in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present application can also be implemented. The division of the following embodiments is for the convenience of description, and the specific implementation of the present application should not be construed as any limitation, and the various embodiments can be combined and referenced with each other under the premise of no contradiction.

[0032] In order to facilitate understanding of why the array antenna calibration method provided in this embodiment of the present application can achieve calibration and decoupling of each channel in the array antenna, the calibration problem of the array antenna under the coupling condition is first analyzed here.

[0033] Assume that the array response matrix of a certain array antenna is A; the coupling relationship of the array antenna is linearized and expressed in the form of coupling matrix C; the error of each analog channel in the array antenna is expressed by diagonal matrix E; the excitation vector of the array antenna under a certain beam is g (the excitation vector corresponding to each beam is known). Then, the directional pattern data f of the array antenna at a certain spatial sampling point can be expressed by formula (1):

[0034] f=ACEg (1)

[0035] Among them, the pattern data f is to be measured, the array response matrix A is known, and the amplitude and phase error used to determine the target calibration weight in this embodiment, that is, the coupled channel amplitude and phase error (also called the coupled channel amplitude and phase error vector), can be expressed by "CEg" in formula (1). For the convenience of subsequent use, this embodiment uses e c represents the amplitude and phase error vector of the coupled channel, which is shown in formula (2):

[0036] e c =CEg 0 (2)

[0037] Among them, g 0 is a unit vector, and its specific value is: g 0 =[1 1 1…1].

[0038] About g 0 The number of "1"s in the corresponding value set depends on the number of array elements of the array antenna in the constructed array response matrix.

[0039] Combining formula (1) and formula (2), the process of solving the amplitude and phase error vector of the coupled channel is shown in formula (3):

[0040]

[0041] Among them, . / means dot division. The element representation is:

[0042]

[0043] Among them, e j , g j They represent the initial amplitude and phase errors and array element excitation corresponding to the jth array element in the array antenna respectively; c ij represents the coupling emission from the jth array element to the ith array element in the array antenna; e ci It represents the channel amplitude and phase error of the i-th element with coupling in the array antenna.

[0044] It can be seen from the above formulas (1), (2), (3) and (4) that the amplitude and phase errors to be calculated are related to the array excitation of the array antenna. That is, when coupling exists, the channel amplitude and phase errors are not fixed, but change with the change of array excitation. This is somewhat contradictory. When the calibration is completed for the first time, if the calibration weights are directly substituted into the system, the excitation will change compared to before the calibration, and the corresponding amplitude and phase errors will also change. Therefore, the calibration weights at this time are not applicable to the system after adding the calibration weights. Although the error caused by coupling is small, it can no longer meet the high consistency requirements of the MIMO system channel.

[0045] To solve this problem, an embodiment of the present application provides an array antenna calibration method that uses an adaptive method to reduce the influence of front-to-back calibration errors. The array antenna calibration method involved in the embodiment of the present application continuously obtains the antenna pattern data of the array antenna under test, thereby obtaining the antenna pattern data vector, and combines it with the array response matrix that can reflect the array antenna, and uses the least squares method to solve the coupled channel amplitude and phase errors of each array element in the array antenna under test, and determines the target calibration weights based on the channel amplitude and phase errors to be coupled, and then calibrates the array antenna to be calibrated according to the calculated target calibration weights, thereby realizing the calibration and decoupling of each channel of the millimeter wave band base station antenna.

[0046] That is, the array antenna calibration method provided in this embodiment can effectively solve the amplitude and phase errors between the channels of the base station antenna, thereby improving the sidelobe level of the base station antenna and the array beam scanning capability, thereby increasing the effective radiation power of the entire system and improving the system performance of high-frequency large-scale Massive MIMO communication systems such as 5G millimeter waves.

[0047] The implementation details of the array antenna calibration method of this embodiment of the present application are described below. The following content is only the implementation details provided for ease of understanding and is not necessary for implementing this solution.

[0048] For ease of understanding, the present application embodiment takes the calibration method of the array antenna as an example of a base station antenna in a 5G millimeter wave Massive MIMO communication system. That is, the array antennas mentioned in this embodiment, whether they are array antennas to be tested or array antennas to be calibrated, are all base station antennas in a 5G millimeter wave Massive MIMO communication system.

[0049] The specific process of the first embodiment of the present application is as follows Figure 1 As shown, the specific steps include:

[0050] Step S10: constructing an array response matrix of the array antenna under test relative to the detection antenna.

[0051] Specifically, the array response matrix may be constructed as follows:

[0052] Based on the test environment, that is, using the array antenna under test to simulate the signal transmission and reception operations of the array antenna, and using a calibration system (a system that can implement the calibration method provided in this embodiment), the test environment information generated during the simulation process is obtained, and then the array response matrix of the array antenna under test relative to the detection antenna is constructed according to the obtained test environment information.

[0053] The test environment mentioned above is specifically based on actual usage scenarios of the array antenna and is achieved by simulating these scenarios.

[0054] Furthermore, in practical applications, the array response matrix construction process may also be constructed based on real test environment information obtained from actual signal transmission and reception operations performed by other array antennas.

[0055] It should be noted that, in a specific implementation, the dimension of the array response matrix is ​​determined by the number of spatial sampling points and the number of array elements in the array antenna under test, and the spatial sampling points are determined based on a predetermined radiation pattern of the array antenna under test.

[0056] Assuming that the number of spatial sampling points in the antenna pattern of the measured array antenna is N, and the number of array elements in the measured array antenna is M, the constructed array response matrix A is an N×M dimensional matrix.

[0057] Specifically, the constructed N×M dimensional array response matrix A is as shown in formula (5):

[0058]

[0059] in, It represents the phase and amplitude of the Mth array element in the measured array antenna when the spatial sampling point is N.

[0060] In addition, regarding the test environment information mentioned above, in this embodiment, specifically, the array layout of the array antenna under test, the specific position relative to the phase center of the turntable, the actual distance between the array antenna and the detection antenna, and other information are obtained.

[0061] That is, as long as the above test environment information can be obtained, it can be used regardless of whether it is in a test environment or in an actual applicable environment.

[0062] Furthermore, in a specific implementation, in order to ensure that the determined target calibration weights can be better applied to the subsequent calibration of the array antenna to be calibrated to ensure higher accuracy, the devices involved in the system can be calibrated once before obtaining the test environment information required to construct the array response matrix.

[0063] Specifically, the calibration of the equipment involved in the system mentioned in this embodiment mainly includes zeroing the turntable that fixes the array antenna under test, that is, the turntable is zeroed and calibrated before the test, and the parallelism and pointing deviation between the array antenna under test and the detection antenna are calibrated at the same time, that is, the parallelism and pointing deviation between the array antenna under test and the detection antenna are adjusted to a range that meets the test requirements.

[0064] In addition, the antenna pattern mentioned above is specifically a graph used to characterize the relationship between the antenna radiation characteristics (field intensity amplitude, phase, polarization) and the spatial angle. The complete antenna pattern is a three-dimensional spatial graph, which is drawn by measuring its radiation characteristics point by point (spatial sampling point) on a sphere with a sufficiently large radius r, with the antenna phase center as the sphere center (coordinate origin). In the specific implementation, it can be completed with the assistance of various existing computer drawing software, and the specific drawing process will not be repeated in this embodiment.

[0065] Step S20, testing the antenna pattern of the array antenna under test to obtain an antenna pattern data vector.

[0066] Specifically, in actual applications, the origin of the directional pattern data corresponding to each spatial sampling point in the antenna directional pattern is based on the spatial position of each spatial sampling point in the antenna directional pattern. By controlling the rotation of the turntable on which the array antenna under test is fixed, after turning to the spatial position corresponding to the current spatial sampling point, the signal transmitting device is controlled to transmit a calibration signal, and the signal receiving device is controlled to receive the calibration signal. Then, according to the channel amplitude phase corresponding to the calibration signal transmitted by the signal transmitting device and the channel amplitude phase corresponding to the calibration signal received by the signal receiving device, the channel amplitude phase error corresponding to the current spatial sampling point is determined. Finally, the determined channel amplitude phase error is used as the directional pattern data corresponding to the current spatial sampling point, so that the directional pattern data corresponding to a spatial sampling point in the antenna directional pattern can be obtained.

[0067] That is to say, for each spatial sampling point in the antenna pattern, by determining the corresponding channel amplitude and phase errors in the above manner, the corresponding pattern data can be obtained, and then the pattern data corresponding to all spatial sampling points in the antenna pattern can be obtained, that is, the antenna pattern data vector can be obtained.

[0068] From the above description, we can know that the directional pattern data actually reflects the amplitude and phase, so the directional pattern data at the spatial sampling point can be expressed as

[0069] Accordingly, the antenna pattern data vector mentioned above can be expressed as formula (6):

[0070]

[0071] Among them, F A represents the antenna pattern data vector, N represents the spatial sampling point, Represents the directional pattern data at the Nth spatial sampling point.

[0072] In addition, it is worth mentioning that the calibration signal mentioned above can be a single-frequency signal or a broadband signal in a specific implementation, and this embodiment does not limit this.

[0073] In addition, it should be understood that the purpose of transmitting the calibration signal through the signal transmitting device and receiving the calibration signal through the signal receiving device is mainly to obtain the amplitude and phase error between the signal transmitting device and the signal receiving device. Therefore, in a specific implementation, it can be assumed that the amplitude and phase difference between the array elements in the array antenna under test changes slowly with the frequency, so the amplitude and phase error obtained at the system operating frequency can be selected as the amplitude and phase error between the two.

[0074] Step S30, calculating the coupled channel amplitude and phase errors of each array element in the measured array antenna according to the array response matrix and the antenna pattern data vector, to obtain the amplitude and phase errors of each array element in the measured array antenna.

[0075] From the above description, we can know that the array response matrix reflects the coupling relationship between array antennas, and the antenna pattern data vector records the pattern data of the array elements in the array antenna at different spatial sampling points. Therefore, based on these two, the amplitude and phase errors of each array element in the measured array antenna can be calculated, that is, the vector value that can reflect the coupling relationship and channel amplitude and phase errors.

[0076] For ease of understanding, the array response matrix shown in formula (5) and the antenna pattern data vector shown in formula (6) are taken as examples, and formula (3) is combined to obtain the coupled channel amplitude and phase errors of each element in the array antenna under test. The specific method of obtaining is shown in formula (7):

[0077]

[0078] In addition, it is worth mentioning that in the array antenna calibration method provided in this embodiment, the target calibration weight used to calibrate the array antenna to be calibrated is based on the above-mentioned coupled channel amplitude and phase error (for the sake of ease of description, this embodiment refers to the coupled channel amplitude and phase error as amplitude and phase error), in order to ensure that the determined target calibration weight can be better applied to the calibration of the array antenna, for each array element in the measured array antenna, for each array element in the measured array antenna, after calculating the amplitude and phase error, the maximum phase fluctuation value and the maximum amplitude fluctuation value can be determined according to the amplitude and phase error; then, it is determined whether the maximum phase fluctuation value is not greater than the phase error convergence upper limit value specified by the convergence condition, and whether the maximum amplitude fluctuation value is not greater than the amplitude error convergence upper limit value specified by the convergence condition.

[0079] Correspondingly, if both of the above judgments are met, that is, the maximum phase fluctuation value is not greater than (less than or equal to) the phase error convergence upper limit value specified by the convergence condition, and the maximum amplitude fluctuation value is not greater than (less than or equal to) the amplitude error convergence upper limit value specified by the convergence condition, then it is determined that the amplitude-phase error meets the preset convergence condition.

[0080] Regarding the above judgment process, in specific implementation, it can be implemented by formula (8):

[0081]

[0082] Among them, g ei Indicates the amplitude and phase error calculated during the i-th calibration test, angle max(*) indicates the maximum phase fluctuation value in *, i.e. the maximum phase fluctuation value mentioned above, dB max (*) indicates the maximum amplitude fluctuation value in *, that is, the maximum amplitude fluctuation value mentioned above. Indicates the upper limit of phase error convergence, in degrees, G l Indicates the upper limit of the amplitude error convergence, specifically in dB.

[0083] In addition, in a specific implementation, the maximum phase fluctuation value can be determined based on formula (9), and the maximum amplitude fluctuation value can be determined based on formula (10):

[0084] angle max (*)=max(angle(*))-min(angle(*)) (9)

[0085] dB max (g ei )=max(dB(g ei ))-min(dB(g ei )) (10)

[0086] Among them, the angle involved in formula (9) max (*), satisfying the following conditions: 0≤angle max (*)≤180.

[0087] Step S40, when the amplitude and phase errors obtained from two adjacent calibration tests meet a preset convergence condition, the test is terminated, and a target calibration weight is determined according to the amplitude and phase errors obtained from two adjacent calibration tests.

[0088] That is, after the convergence of the amplitude and phase errors obtained from each calibration test is judged by the above formula (8), if the amplitude and phase errors obtained from two adjacent calibration tests both meet the preset convergence conditions, the test is terminated, and the target calibration weight is determined based on the amplitude and phase errors obtained from the two adjacent calibration tests.

[0089] Regarding the method of determining the target calibration weight according to the amplitude and phase errors satisfying the convergence condition obtained from two adjacent calibration tests, it can be specifically implemented by combining formula (11) and formula (12):

[0090] g e,i =g e,i *g e,i-1 (11)

[0091] Among them, g e,0 =[1,1,1,…1].

[0092] c e,i =1 / g e,i (12)

[0093] It can be seen from formula (11) and formula (12) that when determining the target calibration weight, the amplitude-phase errors that meet the convergence conditions obtained from two adjacent calibration tests are multiplied, and then the obtained product is used as the final amplitude-phase error for determining the target calibration weight. Finally, the amplitude-phase error calculated in formula (11) is converted according to formula (12) to convert the amplitude-phase error into the target calibration weight.

[0094] Correspondingly, if after the convergence judgment is performed through formula (8), it is found that the amplitude and phase errors obtained in this calibration test do not meet the preset convergence conditions, the calibration test is performed again, that is, the termination condition of the iterative training is that the amplitude and phase errors meet the above-mentioned convergence conditions.

[0095] In addition, it is worth mentioning that the above calibration test process given in this embodiment can be specifically applicable to an indoor far-field calibration environment, a planar near-field calibration environment (also called: an indoor near-field calibration environment) and a compact field calibration environment.

[0096] For ease of understanding, this implementation combines Figure 2 Given the indoor far-field calibration environment, Figure 3 Given a planar near-field calibration environment and Figure 4 The compact field calibration environment is given, and the equipment and devices involved in these three test environments are explained:

[0097] like Figure 2 As shown, in the process of calibrating the array antenna under test based on the indoor far-field calibration environment, the turntable 400 for fixing the array antenna under test 200 and the detection antenna bracket 600 for fixing the detection antenna 300 need to be placed in the darkroom 100.

[0098] from Figure 2 It can be seen that in a specific implementation, the turntable 400 used in the indoor far-field calibration environment is specifically composed of a fixing part 401 for fixing the array antenna 200 under test and a supporting part 402 (which can also be called a base) for supporting the fixing part 401 .

[0099] The part of the fixing part 401 in contact with the supporting part 401 can rotate left and right, and the part in contact with the array antenna 200 under test can rotate online. By rotating these two parts, the turntable can be controlled to rotate to the spatial position of a specific spatial sampling point.

[0100] Furthermore, in practical applications, in order to achieve control over the array antenna under test, a beam controller 500 needs to be provided at the location where the fixing portion 401 of the turntable 400 contacts the array antenna 200 under test.

[0101] In addition, in order to calibrate the parallelism and pointing deviation between the array antenna 200 under test and the detection antenna 300, a position calibration device 700 can also be set on the detection antenna bracket 600 to calibrate the parallelism and pointing deviation between the array antenna 200 under test and the detection antenna 300.

[0102] In addition, it is worth mentioning that in practical applications, in order to ensure the implementation of the above solution, Figure 2 In the indoor far-field calibration environment shown in FIG. 1 , in addition to the above-mentioned equipment and devices included in the darkroom 100, a calibration system or calibration device based on the calibration method of the array antenna provided in this embodiment is required outside the darkroom 100, that is, Figure 2 The amplitude and phase error calibration module shown in the figure is in communication connection with the array antenna 200 under test, the detection antenna 300, the turntable 400 and the beam controller 500 in the darkroom 100, so as to control the above-mentioned devices in the darkroom 100 and complete the determination of the target calibration weight according to the array antenna calibration method provided in this embodiment.

[0103] like Figure 3 As shown, in the process of calibrating the array antenna under test based on the indoor near-field calibration environment, it is also necessary to place the turntable 400 for fixing the array antenna under test 200 and the detection antenna bracket 800 for fixing the detection antenna 300 in the darkroom 100, and outside the darkroom 100, it is also necessary to place the calibration system or calibration device implemented by the calibration method for the array antenna provided in this embodiment, that is, Figure 3 The amplitude and phase error calibration module shown in the figure is in communication connection with the array antenna 200 under test, the detection antenna 300, the turntable 400 and the beam controller 500 in the darkroom 100, so as to control the above-mentioned devices in the darkroom 100 and complete the determination of the target calibration weight according to the array antenna calibration method provided in this embodiment.

[0104] from Figure 3 It can be seen that for the indoor near-field calibration environment, the equipment and devices located in the darkroom 100 are Figure 2 The equipment and devices in the darkroom 100 for the indoor far-field calibration environment shown in FIG. 1 are substantially the same, with the main differences being:

[0105] In an indoor near-field calibration environment, the detection antenna bracket 800 used to fix the detection antenna 300 is a planar scanning bracket.

[0106] For this detection antenna bracket, a sliding device 900 that can slide left and right and up and down is arranged thereon, and the detection antenna 300 is fixed on the sliding device 900 .

[0107] like Figure 4As shown, in the process of calibrating the array antenna under test based on the compact field calibration environment, the turntable 400 and the detection antenna 300 for fixing the array antenna under test 200 also need to be placed in the darkroom 100, and outside the darkroom 100, a calibration system or calibration device implemented by the calibration method for the array antenna provided in this embodiment also needs to be placed. Figure 4 The amplitude and phase error calibration module shown in the figure is in communication connection with the array antenna 200 under test, the detection antenna 300, the turntable 400 and the beam controller 500 in the darkroom 100, so as to control the above-mentioned devices in the darkroom 100 and complete the determination of the target calibration weight according to the array antenna calibration method provided in this embodiment.

[0108] from Figure 4 It can be seen that for the compact field calibration environment, there is no need to set up a detection antenna bracket specifically for fixing the detection antenna 300, that is, the detection antenna 300 is directly fixed to the inner top wall of the darkroom 100. For this situation, although the turntable located in the darkroom 100 also includes a fixing part 401 and a supporting part 402, the fixing part 401 for fixing the array antenna 200 under test only needs to be rotated left and right.

[0109] In addition, it is worth mentioning that in practical applications, a target calibration weight storage module for storing target calibration weights can also be provided on the side of the array antenna under test. Specifically, the target calibration weight storage module is usually connected to the beam controller 500 for communication. Figure 2 , Figure 3 and Figure 4 .

[0110] In addition, it is not difficult to find from the above description that since the amplitude and phase error calibration module is communicated with the array antenna 200 under test, the detection antenna 300, the turntable 400 and the beam controller 500 in the darkroom 100, it is possible to control these devices, thereby realizing the reception and transmission of signals, thereby ensuring that the calibration method of the array antenna provided in this embodiment can proceed smoothly.

[0111] In addition, it should be noted that in practical applications, Figure 2 , Figure 3 and Figure 4 The target calibration weight storage module drawn from the beam controller 500 by the dotted line can usually be integrated in the beam controller 500, that is, the beam controller 500 mentioned in this embodiment has both the beam control function and the target calibration weight storage function.

[0112] It should be understood that the above examples are merely examples listed for a better understanding of the technical solution of this embodiment and are not intended to be the sole limitation to this embodiment.

[0113] Step S50: calibrate the array antenna to be calibrated according to the target calibration weight.

[0114] Specifically, the operation in step S50 may be performed during the use of the array antenna to be calibrated, or before the use of the array antenna to be calibrated, or a combination of the two.

[0115] For example, before using the array antenna to be calibrated, the array antenna to be calibrated is first calibrated once based on the above method, and the determined target calibration weights are stored in the calibration weight storage module.

[0116] Furthermore, after completing the above-mentioned calibration operation, during the use of the array antenna to be calibrated (the array antenna that has undergone a calibration operation once), the stored target calibration weights can be obtained from the calibration weight storage module according to actual conditions to perform a second calibration on the current array antenna, thereby effectively ensuring the accurate calibration of the array antenna.

[0117] It should be noted that, in practical applications, the above-mentioned array antenna under test and the array antenna to be calibrated can be the same array antenna, that is, when a certain array antenna is put into use, the array antenna is directly tested as the array antenna under test, and then the target calibration weight is determined based on the test, and it can be calibrated in subsequent use.

[0118] Specifically, in actual applications, the array antenna located in the base station can both transmit signals outward, that is, it is suitable for downlink channel scenarios, and receive signals, that is, it is suitable for uplink channel scenarios. In order to better understand the signal flow between the detected array antenna 200 (which can be regarded as the array antenna to be calibrated mentioned above), the detection antenna 300 and the beam controller 500 when calibrating the downlink signal in the downlink channel scenario, and the signal flow between the detected array antenna 200, the detection antenna 300 and the beam controller 500 when calibrating the uplink signal in the uplink channel scenario, the following is combined with Figure 5 and Figure 6 Provide specific instructions.

[0119] from Figure 5 and Figure 6 It can be seen that no matter whether the calibration is performed on the downlink channel signal or the uplink channel signal, in the two scenarios, except for the different signal directions (downlink is: the array antenna under test transmits a signal to the detection antenna; uplink is: the array antenna under test receives the signal transmitted by the detection antenna), the division of the internal functional modules is the same.

[0120] Specifically, the array antenna 200 under test can be divided into a power divider network 201 , an amplitude modulation and phase modulation module 202 , a power amplifier module 203 and an antenna module 204 .

[0121] Among them, for the downlink channel, the power divider network 201 is mainly used to divide the digital signal into multiple channels and send it equally to each analog channel; the amplitude modulation and phase modulation module 202 is mainly used to perform phase modulation and amplitude modulation according to the control signal transmitted by the beam controller 500, so as to complete the beamforming function; the power amplifier module 203 is mainly used to increase the signal transmission power; the antenna module 204 is mainly used to transmit signals to space and complete the conversion of radio frequency signals and electromagnetic wave signals.

[0122] For the uplink channel, the power divider network 201 is mainly used to combine the signals of each analog channel and output the combined signal to the corresponding digital channel; the amplitude modulation and phase modulation module 202 is mainly used to perform phase modulation and amplitude modulation according to the control signal transmitted by the beam controller 500, so as to complete the beamforming function to realize the adaptive function; the power amplifier module 203 is mainly used to amplify the power of the spatial signal received by the antenna module 204; the antenna module 204 is mainly used to receive the spatial signal and complete the conversion of the radio frequency signal and the electromagnetic wave signal.

[0123] The beam controller 500 , whether in the downlink channel or the uplink channel, is used to load predetermined target calibration weights according to the specified beam information of the baseband system, generate calibrated beam excitation, and transmit the excitation to the amplitude modulation and phase modulation module 203 .

[0124] Furthermore, in practical applications, a target calibration weight storage module communicatively connected to the beam controller 500 and an amplitude and phase error calibration module communicatively connected to the target calibration weight storage module may also be set in a calibration device implemented based on the array antenna calibration method provided in this embodiment.

[0125] Correspondingly, the target calibration weight storage module is specifically used to store the target calibration weight determined based on the above steps.

[0126] In addition, the signal transmitting device and the signal receiving device used in the above-mentioned array antenna calibration method, as well as the module for performing antenna pattern testing to obtain antenna pattern data vectors and the module for calculating target calibration weights are not provided in the present invention. Figure 5 and Figure 6 Shown in.

[0127] However, in a specific implementation, the realization of the above-mentioned array antenna calibration method needs to rely on a signal sending device to transmit specified calibration information and transmit the calibration signal to the array antenna in the system under test; the signal receiving device needs to receive the calibration signal returned by the system under test.

[0128] Correspondingly, the pattern test module, specifically, controls the turntable to turn to the specified direction during the triggering pattern test, receives the actual steering information of the turntable, and controls the signal transmitting device and the signal receiving device to obtain the pattern data of the array antenna at the specified direction.

[0129] The calibration weight calculation module obtains the array response matrix based on the actual information of the array antenna in the test environment, and calculates the amplitude and phase errors in combination with the pattern data set transmitted by the pattern test module. Then, combined with the convergence conditions, it is determined whether the amplitude and phase error data converge. If the amplitude and phase error data converge, the calibration test is stopped; if not, the pattern test module is controlled to trigger a new calibration process until the amplitude and phase error meets the convergence conditions, and then the target calibration weights are generated based on the two adjacent amplitude and phase error data that meet the convergence conditions, and the calibration weights are transmitted to the calibration weight storage module for subsequent calibration of the array antenna to be calibrated.

[0130] It should be understood that the above examples are merely examples listed for a better understanding of the technical solution of this embodiment and are not intended to be the sole limitation to this embodiment.

[0131] It is not difficult to find from the above description that the calibration method of the array antenna provided in this embodiment constructs an array response matrix relative to the detection antenna based on the array antenna under test, and tests the antenna radiation pattern of the array antenna under test, thereby obtaining antenna radiation pattern data that can reflect the channel amplitude and phase errors corresponding to each array element in the array antenna, and then obtains the amplitude and phase errors that can reflect both the coupling relationship and the channel amplitude and phase errors based on the array response matrix and the antenna radiation pattern data, and monitors the convergence of the amplitude and phase errors, and finally determines the target calibration weights suitable for the array antenna according to the amplitude and phase errors that meet the convergence conditions obtained from two adjacent calibration tests, so that the calibration of the array antenna to be calibrated can be achieved according to the target calibration weights, without adding any hardware equipment to the array antenna to be calibrated.

[0132] In addition, since the target calibration weight is determined based on the amplitude-phase error that can reflect the coupling relationship and the channel amplitude-phase error, the antenna to be calibrated can also be decoupled during the calibration process of the array antenna to be calibrated according to the target calibration weight.

[0133] In addition, since the target calibration weights are determined based on the amplitude and phase errors that meet the convergence conditions, that is, the target calibration weights used to calibrate the array antenna to be calibrated are obtained through iterative training, it is ensured that the target calibration weights can be better applied to the array antenna to be calibrated, thereby meeting the higher precision calibration requirements for the array antenna.

[0134] The second embodiment of the present application relates to a calibration method for an array antenna. This embodiment mainly provides a specific calibration method for an array antenna to be calibrated based on a target calibration weight. Figure 7 It is not difficult to find that steps S10 to S40 in this embodiment are substantially the same as steps S10 and S40 in the first embodiment, and are not described in detail here. The following mainly describes two specific sub-steps in step S50:

[0135] Sub-step S51, during use of the array antenna to be calibrated, receiving beam information, and generating beamforming weights corresponding to the analog channel according to the beam information.

[0136] For the convenience of description, this embodiment is specifically described by taking a downlink channel scenario as an example.

[0137] Specifically, when it is necessary to transmit a signal through the array antenna to be calibrated, the beam controller first receives the beam information sent by the baseband processing module (or baseband processor, baseband processing chip), and then generates the beamforming weights corresponding to each analog channel under the specified beam according to the beam information.

[0138] Regarding the representation of beamforming weights, it can be specifically expressed using formula (13):

[0139]

[0140] Among them, G bf,i Represents the beamforming weight corresponding to the i-th analog channel. The value is a complex number.

[0141] In addition, it should be noted that the beamforming weights can be formulated offline and read in the form of a lookup table during work, thereby further improving processing efficiency and reducing the occupation of system resources.

[0142] Sub-step S52, performing amplitude and phase error compensation processing on the forward signal of the analog channel according to the target calibration weight and the beamforming weight, so as to achieve calibration of the array antenna to be calibrated.

[0143] Specifically, in the case where the target calibration weight is determined through the operations of steps S10 to S40, pre-iterative training, and stored in a target calibration weight storage module, when executing sub-step S52, the beam controller specifically reads the stored target calibration weight from the target calibration weight storage module.

[0144] The read target calibration weight can be specifically expressed by formula (14):

[0145]

[0146] Among them, Ce,i Represents the calibration weight of the i-th analog channel. The value is a complex number.

[0147] In addition, the operation of performing amplitude and phase error compensation processing on the forward signal of the analog channel according to the target calibration weight and the beamforming weight in sub-step S52 can be combined with Figure 8 accomplish:

[0148] like Figure 8 As shown, first, after obtaining the required beamforming weights and target calibration weights, the beamforming weights are calibrated according to the target calibration weights. In a specific implementation, the beamforming weights and the target calibration weights are input into a multiplier, and after the multiplier performs multiplication operation, the obtained product is used as the target beamforming weights, that is, the beamforming weights calibrated by the target calibration weights; then, according to the target beamforming weights, the forward signal of the analog channel is compensated for amplitude and phase errors. In a specific implementation, the forward signal and the target beamforming weights are input into a multiplier, and after the multiplier performs multiplication operation, the obtained product is used as the calibrated output signal.

[0149] The forward signal mentioned above is obtained through the following processing flow:

[0150] When a signal to be transmitted is received, the baseband processing is first performed on the signal to be transmitted through a baseband processing module (or baseband processor, baseband processing chip) to obtain a baseband signal that meets the requirements; then, the obtained baseband signal is subjected to an amplitude factor reduction (CFR) processing to reduce the amplitude of the baseband signal to a preset requirement; then, the baseband signal with the amplitude reduced to the preset requirement is subjected to digital predistortion processing; then, the baseband signal after the digital predistortion processing is subjected to digital-to-analog conversion processing, that is, the digital signal is converted into an analog signal, and then the analog signal is input into the power divider network of the array antenna, the digital signal is divided into multiple channels, and is sent equally to each analog channel, at which time the forward signals of each analog channel that need to be processed appear.

[0151] In addition, it is worth mentioning that in practical applications, after the above-mentioned calibration processing, that is, the amplitude and phase error compensation processing, the output signal after the amplitude and phase error compensation processing can also be power amplified to generate a radio frequency signal that meets the power requirements; finally, the radio frequency signal is sent through the array elements in the array antenna to be calibrated.

[0152] Therefore, the array antenna calibration method provided in this embodiment adopts the above-mentioned method to calibrate the array antenna to be calibrated, and there is no need to add any hardware equipment to the array antenna to be calibrated, so as to realize the calibration and decoupling of the array antenna to be calibrated, and also meet the higher precision calibration requirements for the array antenna.

[0153] In addition, it should be understood that the step division of the above methods is only for clear description. When implemented, they can be combined into one step or some steps can be split and decomposed into multiple steps. As long as they include the same logical relationship, they are all within the scope of protection of this patent; adding insignificant modifications to the algorithm or process or introducing insignificant designs that do not change the core design of the algorithm and process are all within the scope of protection of this patent.

[0154] The third embodiment of the present application relates to a calibration device for an array antenna, such as Fig. 9 As shown, it includes: a target calibration weight determination module 901 and an array antenna calibration module 902.

[0155] The target calibration weight determination module 901 is used to construct an array response matrix of the array antenna under test relative to the detection antenna.

[0156] Furthermore, the target calibration weight determination module 901 is also used to test the antenna pattern of the array antenna under test to obtain the antenna pattern data vector.

[0157] Furthermore, the target calibration weight determination module 901 is also used to calculate the coupled channel amplitude and phase errors of each array element in the measured array antenna based on the array response matrix and the antenna pattern data vector, so as to obtain the amplitude and phase errors of each array element in the measured array antenna.

[0158] Furthermore, the target calibration weight determination module 901 is also used to end the test when the amplitude and phase errors obtained from two adjacent calibration tests meet a preset convergence condition, and determine the target calibration weight according to the amplitude and phase errors obtained from two adjacent calibration tests.

[0159] The array antenna calibration module 902 is used to calibrate the array antenna to be calibrated according to the target calibration weight.

[0160] In addition, in another example, when the target calibration weight determination module 901 constructs the array response matrix of the array antenna under test relative to the detection antenna, specifically:

[0161] Obtaining the array layout of the array antenna under test, the specific position relative to the phase center of the turntable, and the actual distance between the array antenna under test and the detection antenna to obtain test environment information;

[0162] The array response matrix of the array antenna under test relative to the detection antenna is constructed according to the test environment information.

[0163] Furthermore, in another example, in order to ensure the accuracy of the target calibration weights finally determined as much as possible, the array antenna calibration device may further include a device calibration module.

[0164] Specifically, the device calibration module is used to perform zero calibration on the turntable and calibrate the parallelism and pointing deviation between the array antenna under test and the detection antenna before the target weight determination module 901 obtains the array layout of the array antenna under test, the specific position relative to the phase center of the turntable, and the actual distance between the turntable and the detection antenna to obtain the test environment information.

[0165] In addition, in another example, the target weight determination module, when testing the antenna pattern of the array antenna under test and obtaining the antenna pattern data vector, is specifically:

[0166] According to the spatial position of each spatial sampling point in the antenna radiation pattern, control the turntable on which the array antenna under test is fixed to turn, control the signal transmitting device to transmit the calibration signal, and control the signal receiving device to receive the calibration signal;

[0167] Determine a channel amplitude and phase error corresponding to a current spatial sampling point according to the channel amplitude and phase corresponding to the calibration signal transmitted by the signal transmitting device and the channel amplitude and phase corresponding to the calibration signal received by the signal receiving device, and use the determined channel amplitude and phase error as the directional pattern data corresponding to the current spatial sampling point;

[0168] For each spatial sampling point, the corresponding channel amplitude and phase errors are determined in the above manner to obtain the antenna pattern data vector.

[0169] Furthermore, in another example, in order to determine whether the calculated amplitude and phase errors meet the convergence condition, the array antenna calibration device may further include a convergence judgment module.

[0170] Specifically, for each array element in the array antenna under test, the convergence judgment module is used to determine the maximum phase fluctuation value and the maximum amplitude fluctuation value according to the amplitude-phase error;

[0171] It is determined whether the maximum phase fluctuation value is not greater than the phase error convergence upper limit value specified by the convergence condition, and whether the maximum amplitude fluctuation value is not greater than the amplitude error convergence upper limit value specified by the convergence condition.

[0172] Correspondingly, if the maximum phase fluctuation value is not greater than the phase error convergence upper limit value specified by the convergence condition, and the maximum amplitude fluctuation value is not greater than the amplitude error convergence upper limit value specified by the convergence condition, it is determined that the amplitude-phase error meets the convergence condition.

[0173] In addition, in another example, when the array antenna calibration module 902 calibrates the array antenna to be calibrated according to the target calibration weight, specifically:

[0174] During use of the array antenna to be calibrated, beam information is received, and beamforming weights corresponding to the analog channel are generated according to the beam information;

[0175] According to the target calibration weight and the beamforming weight, amplitude and phase error compensation processing is performed on the forward signal of the analog channel to achieve calibration of the array antenna to be calibrated.

[0176] In addition, in another example, when the array antenna calibration module 902 performs amplitude and phase error compensation processing on the forward signal of the analog channel according to the target calibration weight and the beamforming weight, specifically:

[0177] Calibrate the beamforming weight according to the target calibration weight to obtain a target beamforming weight;

[0178] According to the target beamforming weight, amplitude and phase error compensation processing is performed on the forward signal of the analog channel.

[0179] In addition, in another example, the array antenna calibration module 902 is also used to perform power amplification processing on the output signal after the amplitude and phase error compensation processing to generate a radio frequency signal that meets the power requirement; and send the radio frequency signal through the array elements in the array antenna to be calibrated.

[0180] It is not difficult to find that this embodiment is a device embodiment corresponding to the first or second embodiment, and this embodiment can be implemented in conjunction with the first or second embodiment. The relevant technical details mentioned in the first or second embodiment are still valid in this embodiment, and in order to reduce repetition, they are not repeated here. Accordingly, the relevant technical details mentioned in this embodiment can also be applied in the first or second embodiment.

[0181] It is worth mentioning that all modules involved in this embodiment are logic modules. In practical applications, a logic unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. In addition, in order to highlight the innovative part of this application, this embodiment does not introduce units that are not closely related to solving the technical problems proposed by this application, but this does not mean that there are no other units in this embodiment.

[0182] The fourth embodiment of the present application relates to a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the calibration method of the array antenna described in the above method embodiment is implemented.

[0183] That is, those skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a program, and the program is stored in a, including several instructions to enable a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0184] Those skilled in the art will appreciate that the above embodiments are specific embodiments for implementing the present application, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present application.

Claims

1. A calibration method for an array antenna, characterized in that: include: Constructing an array response matrix of the array antenna under test relative to the detection antenna; Testing the antenna pattern of the array antenna under test to obtain the antenna pattern data vector; Calculating the coupled channel amplitude and phase errors of each array element in the measured array antenna according to the array response matrix and the antenna pattern data vector to obtain the amplitude and phase errors of each array element in the measured array antenna; When the amplitude and phase errors obtained from two adjacent calibration tests both meet a preset convergence condition, the test is terminated, and a target calibration weight is determined based on the amplitude and phase errors obtained from the two adjacent calibration tests; The array antenna to be calibrated is calibrated according to the target calibration weight.

2. The method for calibrating an array antenna according to claim 1, wherein: The step of constructing an array response matrix of the array antenna under test relative to the detection antenna comprises: Obtaining the array layout of the array antenna under test, the specific position relative to the phase center of the turntable, and the actual distance between the array antenna under test and the detection antenna to obtain test environment information; The array response matrix of the array antenna under test relative to the detection antenna is constructed according to the test environment information.

3. The method for calibrating an array antenna according to claim 2, wherein: Before obtaining the array layout of the array antenna under test, the specific position relative to the phase center of the turntable, and the actual distance between the array antenna under test and the detection antenna to obtain the test environment information, the method further includes: The turntable is zero-calibrated, and the parallelism and pointing deviation between the array antenna under test and the detection antenna are calibrated.

4. The method for calibrating an array antenna according to claim 1, wherein: Test the antenna pattern of the array antenna under test and obtain the antenna pattern data vector, including: According to the spatial position of each spatial sampling point in the antenna radiation pattern, control the turntable on which the array antenna under test is fixed to turn, control the signal transmitting device to transmit the calibration signal, and control the signal receiving device to receive the calibration signal; Determine a channel amplitude and phase error corresponding to a current spatial sampling point according to the channel amplitude and phase corresponding to the calibration signal transmitted by the signal transmitting device and the channel amplitude and phase corresponding to the calibration signal received by the signal receiving device, and use the determined channel amplitude and phase error as the directional pattern data corresponding to the current spatial sampling point; For each spatial sampling point, the corresponding channel amplitude and phase errors are determined in the above manner to obtain the antenna pattern data vector.

5. The method for calibrating an array antenna according to claim 1, wherein: After calculating the coupled channel amplitude and phase errors of each array element in the measured array antenna according to the array response matrix and the antenna pattern data vector to obtain the amplitude and phase errors of each array element in the measured array antenna, the method further includes: For each array element in the measured array antenna, determining a maximum phase fluctuation value and a maximum amplitude fluctuation value according to the amplitude-phase error; Determine whether the maximum phase fluctuation value is not greater than the phase error convergence upper limit value specified by the convergence condition, and whether the maximum amplitude fluctuation value is not greater than the amplitude error convergence upper limit value specified by the convergence condition; If so, it is determined that the amplitude and phase errors meet the convergence condition.

6. The method for calibrating an array antenna according to any one of claims 1 to 5, characterized in that: The step of calibrating the array antenna to be calibrated according to the target calibration weight includes: During use of the array antenna to be calibrated, beam information is received, and beamforming weights corresponding to the analog channel are generated according to the beam information; According to the target calibration weight and the beamforming weight, amplitude and phase error compensation processing is performed on the forward signal of the analog channel to achieve calibration of the array antenna to be calibrated.

7. The method for calibrating an array antenna according to claim 6, wherein: The step of performing amplitude and phase error compensation processing on the forward signal of the analog channel according to the target calibration weight and the beamforming weight includes: Calibrate the beamforming weight according to the target calibration weight to obtain a target beamforming weight; According to the target beamforming weight, amplitude and phase error compensation processing is performed on the forward signal of the analog channel.

8. The method for calibrating an array antenna according to claim 6, wherein: After performing amplitude and phase error compensation processing on the forward signal of the analog channel according to the target calibration weight and the beamforming weight, the method further includes: Performing power amplification processing on the output signal after the amplitude and phase error compensation processing to generate a radio frequency signal that meets the power requirement; The radio frequency signal is sent through array elements in the array antenna to be calibrated.

9. A calibration device for an array antenna, characterized in that: include: Target calibration weight determination module and array antenna calibration module; The target calibration weight determination module is used to construct an array response matrix of the array antenna under test relative to the detection antenna; The target calibration weight determination module is also used to test the antenna pattern of the array antenna under test and obtain the antenna pattern data vector; The target calibration weight determination module is further used to calculate the coupled channel amplitude and phase error of each array element in the measured array antenna according to the array response matrix and the antenna pattern data vector, so as to obtain the amplitude and phase error of each array element in the measured array antenna; The target calibration weight determination module is further used to end the test when the amplitude and phase errors obtained from two adjacent calibration tests meet a preset convergence condition, and determine the target calibration weight according to the amplitude and phase errors obtained from two adjacent calibration tests; The array antenna calibration module is used to calibrate the array antenna to be calibrated according to the target calibration weight.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the array antenna calibration method according to any one of claims 1 to 8 is implemented.

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