Method and system for amplitude and phase calibration of dual polarized measurement probes

Abstract

The application provides a method and system for amplitude and phase calibration of a dual-polarized measurement probe, wherein a calibration polarization direction of a standard antenna and a polarization alignment angle when a first polarization direction of the dual-polarized measurement probe is aligned are determined first, then a calibration angle is determined according to the polarization alignment angle and a preset angle, the standard antenna or the dual-polarized measurement probe is driven to rotate around an axis to the calibration angle, and responses (i.e. first S parameters and second S parameters) of two polarization channels are synchronously obtained in one static measurement, so that calibration measurement errors caused by mechanical indexing errors are fundamentally eliminated, and finally, relative amplitude calibration information and relative phase calibration information between the first polarization channel and the second polarization channel of the dual-polarized measurement probe calculated based on the preset angle, the first S parameters and the second S parameters have high accuracy, the precision of phase calibration is effectively improved, and the overall accuracy of amplitude and phase calibration is ensured.

Description

Technical Field

[0001] This invention relates to the technical field of antenna calibration, and in particular to an amplitude and phase calibration method and system for a dual-polarization measurement probe. Background Technology

[0002] In antenna measurement systems, dual-polarized antennas are commonly used as measurement probes to comprehensively characterize the performance of the antenna under test (AUT). Dual-polarized probes can simultaneously measure two orthogonal polarization components at a single point in space, which is crucial for comprehensively evaluating the AUT's performance. To obtain accurate measurement results, the amplitude and phase responses between the two polarization channels of the measurement probe must be precisely calibrated.

[0003] In existing technologies, standard horn antennas (whose gain is known or quantified) are typically used to calibrate the power loss and phase difference information corresponding to different polarization channels of the measurement probe. For example... Figure 1 As shown, the calibration includes the following steps: The standard antenna is installed at the location of the antenna under test, and the relative position and orientation of the standard antenna and the measuring probe are adjusted by a precision mechanical turntable to make them precisely aligned in space. Rotate the Phi axis to align the polarization direction of the standard antenna (either the direction of single polarization or one of the polarization directions of dual polarization) with the first polarization of the measurement probe, and measure and record the S-parameters at this time. Rotate the Phi axis again to align the polarization direction of the standard antenna with the second polarization of the measurement probe, and measure and record the S-parameters at this point. By comparing the amplitudes of the two S-parameters with the known standard antenna gain, the amplitude calibration information of the two polarization channels of the measurement probe is calculated; by calculating the phase difference of the two S-parameters, the phase calibration information of the two polarization channels of the measurement probe is obtained.

[0004] The above process requires two independent mechanical rotation operations. Any mechanical system has uncertainties such as backlash and positioning errors. When the standard antenna rotates from alignment with the first polarization to alignment with the second polarization, the actual position of its phase center in space undergoes a slight change, resulting in an arc-shaped oscillation around the rotation axis. This means that the calibration of the two polarizations of the measurement probe is not performed at the same point in space. For low-frequency measurements, this positional error may be within a tolerable range. However, with the development of high-frequency communication technologies such as 5G millimeter waves and terahertz, wavelengths are drastically shortened, and phase becomes extremely sensitive to changes in spatial position. Micrometer-level positional changes can introduce phase errors of tens of degrees, leading to calibration failure of the entire antenna measurement system (especially in scenarios with strict requirements for polarization purity, sidelobe level, and beam pointing), significantly reducing the reliability of the measurement results. Therefore, there is an urgent need for a calibration method that can eliminate errors introduced by mechanical motion, especially phase errors.

[0005] In summary, the traditional amplitude and phase calibration method for dual-polarization measurement probes introduces non-negligible mechanical errors, resulting in poor accuracy. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide an amplitude and phase calibration method and system for a dual-polarization measurement probe, so as to alleviate the technical problem of poor calibration accuracy caused by non-negligible mechanical motion errors in the traditional amplitude and phase calibration method for dual-polarization measurement probes.

[0007] In a first aspect, the present invention provides an amplitude and phase calibration method for a dual-polarization measurement probe, comprising: Adjust the relative orientation of the standard antenna and the dual-polarization measurement probe to determine the polarization alignment angle when the calibration polarization direction of the standard antenna is aligned with the first polarization direction of the dual-polarization measurement probe, wherein the first polarization direction is any polarization direction of the dual-polarization measurement probe. The calibration angle is determined based on the polarization alignment angle and the preset angle, and the standard antenna or the dual-polarization measurement probe is driven to rotate around its axis to the calibration angle, wherein the value of the preset angle does not include integer multiples of 90 degrees; While maintaining no relative mechanical movement between the standard antenna and the dual-polarization measurement probe, the first S-parameter between the calibration polarization channel of the standard antenna and the first polarization channel of the dual-polarization measurement probe, and the second S-parameter between the calibration polarization channel of the standard antenna and the second polarization channel of the dual-polarization measurement probe are measured simultaneously. Based on the preset angle, the first S-parameter, and the second S-parameter, the relative amplitude calibration information and relative phase calibration information between the first polarization channel and the second polarization channel of the dual polarization measurement probe are calculated.

[0008] Further, the relative attitude of the standard antenna and the dual-polarization measurement probe is adjusted to determine the polarization alignment angle when the calibration polarization direction of the standard antenna is aligned with the first polarization direction of the dual-polarization measurement probe, including: The standard antenna and the dual-polarized measurement probe are initially physically aligned to establish an effective signal transmission link; The standard antenna or the dual-polarization measurement probe is controlled to rotate around its axis in preset angle steps. At each rotation angle, the S-parameter between the calibration polarization channel of the standard antenna and the first polarization channel of the dual-polarization measurement probe is measured. The rotation angle corresponding to the maximum amplitude of the S-parameter is determined, and the rotation angle corresponding to the maximum amplitude is used as the polarization alignment angle.

[0009] Furthermore, after measuring the S-parameters between the calibration polarization channel of the standard antenna and the first polarization channel of the dual-polarization measurement probe at each rotation angle, the method further includes: The S-parameters for each rotation angle are subjected to angle domain interpolation or local curve fitting.

[0010] Furthermore, the preset angle is 45 degrees.

[0011] Furthermore, when the standard antenna is a single-polarized antenna, its single polarization direction is the calibration polarization direction; when the standard antenna is a dual-polarized antenna, one of its two polarization directions is fixed as the calibration polarization direction.

[0012] Furthermore, when there is a positional error in the calibration angle, the calculation result of the relative phase calibration information is not affected by the positional error.

[0013] Furthermore, the amplitude and phase calibration method of the dual-polarization measurement probe is applicable to measurement systems in the microwave, millimeter-wave, or terahertz frequency bands.

[0014] Furthermore, the distance between the standard antenna and the dual-polarized measurement probe is either the far-field distance or the near-field distance; The calculation results of the relative amplitude calibration information and the relative phase calibration information are independent of the distance.

[0015] In a second aspect, the present invention also provides an amplitude and phase calibration system for a dual-polarization measurement probe, for implementing the method as described in any one of the first aspects, the system comprising: A mechanical positioning and rotation device is used to adjust the relative position and orientation of the standard antenna and the dual-polarized measurement probe; Vector network analyzer, used to measure S-parameters; The control and processing unit is configured to perform relevant control and processing operations.

[0016] This invention provides an amplitude and phase calibration method for a dual-polarization measurement probe, comprising: adjusting the relative attitude of a standard antenna and the dual-polarization measurement probe to determine the polarization alignment angle when the calibration polarization direction of the standard antenna is aligned with the first polarization direction of the dual-polarization measurement probe, wherein the first polarization direction is any polarization direction of the dual-polarization measurement probe; determining a calibration angle based on the polarization alignment angle and a preset angle, and driving the standard antenna or the dual-polarization measurement probe to rotate around its axis to the calibration angle, wherein the value of the preset angle does not include integer multiples of 90 degrees; maintaining no relative mechanical movement between the standard antenna and the dual-polarization measurement probe, and simultaneously measuring the first S-parameter between the calibration polarization channel of the standard antenna and the first polarization channel of the dual-polarization measurement probe, and the second S-parameter between the calibration polarization channel of the standard antenna and the second polarization channel of the dual-polarization measurement probe; and calculating the relative amplitude calibration information and relative phase calibration information between the first polarization channel and the second polarization channel of the dual-polarization measurement probe based on the preset angle, the first S-parameter, and the second S-parameter. As described above, the amplitude and phase calibration method of the dual-polarization measurement probe of the present invention first determines the polarization alignment angle when the calibration polarization direction of the standard antenna is aligned with the first polarization direction of the dual-polarization measurement probe. Then, the calibration angle is determined according to the polarization alignment angle and the preset angle, and then the standard antenna or the dual-polarization measurement probe is driven to rotate around its axis to the calibration angle. Then, the responses of the two polarization channels (i.e., the first S-parameter and the second S-parameter) are acquired simultaneously in a static measurement, which fundamentally eliminates mechanical motion errors. Finally, the relative amplitude calibration information and relative phase calibration information between the first polarization channel and the second polarization channel of the dual-polarization measurement probe calculated based on the preset angle, the first S-parameter and the second S-parameter have high accuracy, which can effectively improve the accuracy of phase calibration, thereby ensuring the overall accuracy of amplitude and phase calibration and alleviating the technical problem of poor calibration accuracy caused by the non-negligible mechanical motion error in the traditional amplitude and phase calibration method of dual-polarization measurement probe. Attached Figure Description

[0017] 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.

[0018] Figure 1 A schematic diagram of amplitude and phase calibration for a dual-polarization measurement probe provided by conventional technology; Figure 2 A flowchart illustrating an amplitude and phase calibration method for a dual-polarization measurement probe provided in an embodiment of the present invention; Figure 3This is a schematic diagram of the initial physical alignment provided for an embodiment of the present invention. Detailed Implementation

[0019] 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.

[0020] Traditional amplitude and phase calibration methods for dual-polarization measurement probes suffer from poor calibration accuracy due to non-negligible mechanical errors during movement.

[0021] Based on this, in the amplitude and phase calibration method of the dual-polarization measurement probe of the present invention, the polarization alignment angle when the calibration polarization direction of the standard antenna is aligned with the first polarization direction of the dual-polarization measurement probe is first determined. Then, the calibration angle is determined according to the polarization alignment angle and the preset angle, and then the standard antenna or the dual-polarization measurement probe is driven to rotate around its axis to the calibration angle. Then, the responses of the two polarization channels (i.e., the first S-parameter and the second S-parameter) are acquired simultaneously in a static measurement, which fundamentally eliminates mechanical motion error. Finally, the relative amplitude calibration information and relative phase calibration information between the first polarization channel and the second polarization channel of the dual-polarization measurement probe calculated based on the preset angle, the first S-parameter and the second S-parameter have high accuracy, which can effectively improve the accuracy of phase calibration, thereby ensuring the overall accuracy of amplitude and phase calibration.

[0022] To facilitate understanding of this embodiment, a detailed description of the amplitude and phase calibration method for a dual-polarization measurement probe disclosed in this embodiment of the invention will be provided first.

[0023] Example 1: According to an embodiment of the present invention, an embodiment of an amplitude and phase calibration method for a dual-polarization measurement probe 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.

[0024] Figure 2 This is a flowchart of an amplitude and phase calibration method for a dual-polarization measurement probe according to an embodiment of the present invention, as shown below. Figure 2 As shown, the method includes the following steps: Step S202: Adjust the relative attitude of the standard antenna and the dual-polarization measurement probe to determine the polarization alignment angle when the calibration polarization direction of the standard antenna is aligned with the first polarization direction of the dual-polarization measurement probe, wherein the first polarization direction is any polarization direction of the dual-polarization measurement probe. Specifically, this step includes the processes of initial physical alignment and polarization electrical alignment. These processes will be described in more detail below and will not be repeated here.

[0025] Step S204: Determine the calibration angle based on the polarization alignment angle and the preset angle, and drive the standard antenna or dual-polarization measurement probe to rotate around its axis to the calibration angle. The preset angle does not include integer multiples of 90 degrees. The above process can be implemented in two ways: The first way is to adjust the standard antenna or dual-polarization measurement probe after determining the polarization alignment angle so that the calibration polarization direction of the standard antenna is aligned with the first polarization direction of the dual-polarization measurement probe. On this basis, drive the standard antenna or dual-polarization measurement probe to rotate around its axis by a preset angle, so that the standard antenna or dual-polarization measurement probe rotates to the calibration angle. The second way is to determine the calibration angle based on the polarization alignment angle and the preset angle after determining the polarization alignment angle, and then directly drive the standard antenna or dual-polarization measurement probe to rotate around its axis to the calibration angle.

[0026] Step S206: Keep the standard antenna and the dual-polarization measurement probe without relative mechanical movement, and simultaneously measure the first S-parameter between the calibration polarization channel of the standard antenna and the first polarization channel of the dual-polarization measurement probe, as well as the second S-parameter between the calibration polarization channel of the standard antenna and the second polarization channel of the dual-polarization measurement probe. Specifically, after reaching the calibration angle, the standard antenna and the dual-polarization measurement probe are in a state of no relative mechanical movement. The first S-parameter between the calibration polarization channel of the standard antenna and the first polarization channel of the dual-polarization measurement probe, and the second S-parameter between the calibration polarization channel of the standard antenna and the second polarization channel of the dual-polarization measurement probe are measured. This process can be simply referred to as static synchronous measurement.

[0027] Step S208: Calculate the relative amplitude calibration information and relative phase calibration information between the first polarization channel and the second polarization channel of the dual-polarization measurement probe based on the preset angle, the first S-parameter, and the second S-parameter.

[0028] This invention provides an amplitude and phase calibration method for a dual-polarization measurement probe, comprising: adjusting the relative attitude of a standard antenna and the dual-polarization measurement probe to determine the polarization alignment angle when the calibration polarization direction of the standard antenna is aligned with the first polarization direction of the dual-polarization measurement probe, wherein the first polarization direction is any polarization direction of the dual-polarization measurement probe; determining a calibration angle based on the polarization alignment angle and a preset angle, and driving the standard antenna or the dual-polarization measurement probe to rotate around its axis to the calibration angle, wherein the value of the preset angle does not include integer multiples of 90 degrees; maintaining no relative mechanical movement between the standard antenna and the dual-polarization measurement probe, and simultaneously measuring the first S-parameter between the calibration polarization channel of the standard antenna and the first polarization channel of the dual-polarization measurement probe, and the second S-parameter between the calibration polarization channel of the standard antenna and the second polarization channel of the dual-polarization measurement probe; and calculating the relative amplitude calibration information and relative phase calibration information between the first polarization channel and the second polarization channel of the dual-polarization measurement probe based on the preset angle, the first S-parameter, and the second S-parameter. As described above, the amplitude and phase calibration method of the dual-polarization measurement probe of the present invention first determines the polarization alignment angle when the calibration polarization direction of the standard antenna is aligned with the first polarization direction of the dual-polarization measurement probe. Then, the calibration angle is determined according to the polarization alignment angle and the preset angle, and then the standard antenna or dual-polarization measurement probe is driven to rotate around its axis to the calibration angle. Then, the responses of the two polarization channels (i.e., the first S-parameter and the second S-parameter) are acquired simultaneously in a static measurement, which fundamentally eliminates the calibration measurement error caused by mechanical positioning error. Finally, the relative amplitude calibration information and relative phase calibration information between the first polarization channel and the second polarization channel of the dual-polarization measurement probe calculated based on the preset angle, the first S-parameter and the second S-parameter have high accuracy, which can effectively improve the accuracy of phase calibration, thereby ensuring the overall accuracy of amplitude and phase calibration and alleviating the technical problem of poor calibration accuracy caused by non-negligible mechanical motion error in the traditional amplitude and phase calibration method of dual-polarization measurement probe.

[0029] The above provides a brief overview of the amplitude and phase calibration method for the dual-polarization measurement probe of the present invention. The specific details involved are described in detail below.

[0030] In an optional embodiment of the present invention, adjusting the relative orientation of the standard antenna and the dual-polarization measurement probe to ensure that the calibration polarization direction of the standard antenna is aligned with the first polarization direction of the dual-polarization measurement probe specifically includes the following steps: (1) Initial physical alignment: Perform initial physical alignment between the standard antenna and the dual-polarized measurement probe to establish an effective signal transmission link.

[0031] Specifically, such as Figure 3As shown, the standard antenna a and the dual-polarized measurement probe antenna b are roughly aligned in physical space. This step can be achieved using positioning fixtures such as laser alignment devices, optical crosshairs, and mechanical clamps to ensure that the two antennas are basically in each other's main radiation directions. Figure 3 The standard antenna a shown in the diagram has the main radiation direction z. a Align the main radiation direction z of the dual-polarization measurement probe antenna b b This step does not have stringent requirements for mechanical positioning accuracy. The distance between the standard antenna and the dual-polarized measurement probe is not limited; it can be a far-field distance or a typical working distance for near-field scanning. This process constitutes the initial physical alignment.

[0032] (2) Polarization electrical alignment: Control the standard antenna or dual-polarization measurement probe to rotate around its axis in preset angle steps, specifically, such as Figure 3 As shown, around z a Axial rotation standard antenna a or around z b The axially rotating dual-polarization measurement probe antenna b measures the S-parameters between the calibration polarization channel of the standard antenna and the first polarization channel of the dual-polarization measurement probe at each rotation angle. The rotation angle corresponding to the maximum amplitude of the S-parameters is determined, and the rotation angle corresponding to the maximum amplitude is taken as the polarization alignment angle. This process is called polarization electrical alignment.

[0033] It should be noted that when the standard antenna is a single-polarized antenna, its single polarization direction x a This refers to calibrating the polarization direction, or, when the standard antenna is a dual-polarized antenna, using one of its two polarization directions, x. a As the calibration polarization direction. The measurement probe is a dual-polarized antenna, including: a first polarization direction x b Second polarization direction y b .

[0034] As an example, the process of finding the polarization alignment angle is as follows: control the standard antenna or dual-polarization measurement probe to rotate around its z-axis in preset angular steps, and measure the calibration polarization channel x of the standard antenna through a vector network analyzer at each rotation angle. a With the first polarization channel x of the dual-polarization measurement probe b The amplitude of the S-parameter (S21) between the ranges covers at least 180°. Find the rotation angle corresponding to the maximum amplitude of the S-parameter in the dataset and use the rotation angle corresponding to the maximum amplitude as the polarization alignment angle.

[0035] Note that the resolution of the preset angle here should be small enough to ensure that the peak value of the S-parameter is captured. However, since the measured angle is discrete, directly finding the extreme point based on the measurement data is suitable for situations with a high signal-to-noise ratio and obvious data trends. If a more accurate alignment angle is needed, angle domain interpolation or local curve fitting can be performed on the measured discrete data to obtain S-parameters with higher angle density or continuous characteristics, thereby obtaining a more accurate polarization alignment angle.

[0036] In an optional embodiment of the present invention, there are two execution methods for the process from polarization electrical alignment to driving the standard antenna or dual-polarization measurement probe to rotate around its axis to the calibration angle: The first method is to adjust the standard antenna or dual-polarization measurement probe after determining the polarization alignment angle so that the calibration polarization direction of the standard antenna is aligned with the first polarization direction of the dual-polarization measurement probe. On this basis, the standard antenna or dual-polarization measurement probe is then driven to rotate around its axis by a preset angle, thereby rotating the standard antenna or dual-polarization measurement probe to the calibration angle; The second method is to determine the calibration angle based on the polarization alignment angle and the preset angle after determining the polarization alignment angle, and then directly drive the standard antenna or dual-polarization measurement probe to rotate around its axis to the calibration angle. For example, in the above process, the dual-polarization measurement probe remains stationary, and only the standard antenna is adjusted. Assuming the polarization alignment angle is 10 degrees and the preset angle is 45 degrees, then, according to the first method, after determining the polarization alignment angle to be 10 degrees, the standard antenna is adjusted (axially rotated) to reach 10 degrees. At this point, the calibration polarization direction of the standard antenna is aligned with the first polarization direction of the dual-polarization measurement probe. Based on this, the standard antenna is then driven to rotate axially by the preset angle of 45 degrees. At this point, the standard antenna reaches the calibration angle, i.e., 55 degrees. According to the second method, after determining the polarization alignment angle to be 10 degrees, the calibration angle is first calculated based on the polarization alignment angle of 10 degrees and the preset angle of 45 degrees, resulting in a calibration angle of 55 degrees. Then, the standard antenna is driven to rotate axially to the calibration angle of 55 degrees.

[0037] In an optional embodiment of the present invention, relative amplitude calibration information and relative phase calibration information between the first polarization channel and the second polarization channel of the dual-polarization measurement probe are calculated based on a preset angle, a first S-parameter, and a second S-parameter. Specifically, the first S-parameter S1 represents the transmission coefficient from the standard antenna port to the first port of the dual-polarization antenna (hereinafter referred to as the "first channel"); the second S-parameter S2 represents the transmission coefficient from the standard antenna port to the second port of the dual-polarization antenna (hereinafter referred to as the "second channel"). These two complex S-parameters contain the amplitude and phase responses of their respective channels. The calculation of the relative calibration information aims to quantify the difference between the responses of the two channels, using one channel (designated as the first channel in this embodiment) as a reference to normalize the other channel (i.e., the second channel in this embodiment). For simplicity and clarity, the following explanation uses a preset angle of 45 degrees as an example. When the preset angle is 45 degrees, the calibration polarization direction of the standard antenna lies on the angle bisector of the first and second polarization directions of the dual-polarization measurement probe. That is, the calibration polarization direction of the standard antenna is at a 45-degree angle to both polarization directions of the measurement probe. Ideally, the front ends of the two polarization channels of the measurement probe should receive signals with equal amplitude and phase. Therefore, the amplitude and phase differences of the measured S-parameters originate from the response differences between the two channels themselves, and these response differences can be used for calibration data. An example of the specific calculation method is as follows: Relative amplitude calibration information is defined as the ratio of the amplitude responses of two channels, reflecting the inherent difference in the amplitude of the output signals of the two channels under the same input signal. The calculation formula is as follows:

[0038] in, This indicates relative amplitude calibration information, in decibels (dB). and They represent and The modulus value. Relative phase calibration information is defined as the difference between the phase responses of the two channels. It reflects the inherent phase shift of the output signals of the two channels under the same input signal, and is calculated using the following formula:

[0039] in, This indicates relative phase calibration information, expressed in radians or degrees. This indicates the operation of taking the complex phase angle.

[0040] The calculated relative amplitude calibration information With relative phase calibration information The data is stored as calibration coefficients. In subsequent measurements, the measurement data is calibrated and compensated based on the calibration coefficients to normalize the response between the two polarization channels of the dual-polarization measurement probe.

[0041] In a more general case, where the preset angle is not 45 degrees, let the angle between the calibration polarization direction of the standard antenna and the first polarization direction of the dual-polarization measurement probe be a known angle θ. Then, the angle with the second polarization direction is 90°-θ. According to common knowledge in the art, the ratio of the signal amplitudes received by the two channels of the dual-polarization measurement probe should be cosθ : sinθ. Therefore, the S-parameters of the two channels measured by devices such as a vector network analyzer include the response differences of the channels themselves and the influence of polarization projection on the amplitude. Those skilled in the art will understand that this angle θ does not affect the phase difference between the two channels. This also explains why mechanical alignment errors do not affect the calibration accuracy of this scheme. In this scheme, the calibration accuracy is ensured by calculating the polarization alignment angle and static synchronous measurement. The spatial position error caused by the mechanical error during the initial physical alignment can be effectively canceled out when calculating the relative calibration information. In other words, this scheme accurately obtains the relative calibration information between the two polarization channels, not the absolute loss of the two polarization channels from the standard antenna to the dual-polarization measurement probe. The former is more meaningful for calibration.

[0042] In an optional embodiment of the present invention, the amplitude and phase calibration method of the dual-polarization measurement probe is applicable to measurement systems in the microwave, millimeter-wave, or terahertz frequency bands.

[0043] In an optional embodiment of the present invention, the distance between the standard antenna and the dual-polarized measurement probe is the far-field distance or the near-field distance; the calculation results of the relative amplitude calibration information and the relative phase calibration information are independent of the distance.

[0044] Compared with the prior art, the present invention has the following significant advantages: 1. Completely eliminates the impact of mechanical motion errors on calibration accuracy: In the critical calibration data acquisition step (i.e., the static synchronous measurement step), there is no relative mechanical movement between the standard antenna and the dual-polarization measurement probe. The relative amplitude and phase relationship of the two channels are directly obtained through a single measurement, avoiding the random errors introduced by two independent measurements in traditional methods, resulting in higher calibration repeatability and reliability. The response data of the two polarization channels are acquired under completely identical spatial positions and attitudes, fundamentally eliminating positional uncertainties caused by mechanical rotation, thereby greatly improving the accuracy of phase calibration, especially suitable for high-frequency and ultra-high-frequency bands.

[0045] 2. Reduced Requirements for Mechanical Systems: During initial physical alignment, even minor mechanical errors will not affect the final calibration accuracy due to the calibration logic of this scheme. Similarly, during polarization electrical alignment, even minor mechanical errors can be reduced through mathematical calculations. The system's requirements for absolute accuracy and repeatability of the mechanical structure are significantly reduced, contributing to lower costs and complexity of the entire measurement system. Furthermore, during angle calibration, even minor mechanical errors have minimal impact on subsequent measurements and calculations of the relative amplitude calibration information, and no impact on the relative phase calibration information. Specifically, the error in the relative amplitude calibration data is:

[0046] in, For preset angle, This refers to the actual angle of arrival. For example, when the error is 0.1 degrees, that is... The error value is only 0.01dB.

[0047] The method of the present invention achieves dual-polarization amplitude and phase calibration of a measurement probe with high precision and high repeatability by simultaneously acquiring the responses of two polarization channels in a single measurement without relative motion.

[0048] Example 2: This invention also provides an amplitude and phase calibration system for a dual-polarization measurement probe, used to implement the method described in Embodiment 1. The system includes: A mechanical positioning and rotation device is used to adjust the relative position and orientation of the standard antenna and the dual-polarized measurement probe; Vector network analyzer, used to measure S-parameters; The control and processing unit is configured to perform relevant control and processing operations.

[0049] This invention also provides a computer-readable storage medium storing a computer program. When executed by a processor, this computer program performs the amplitude and phase calibration method for the dual-polarization measurement probe described in the preceding method embodiments. The computer-readable storage medium includes various media capable of storing program code, such as a USB flash drive, portable hard drive, read-only memory (ROM), RAM, magnetic disk, or optical disk.

[0050] In this document, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" in this document means any combination of at least two of any one or more elements. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0051] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limitations; therefore, other examples of exemplary embodiments may have different values.

[0052] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0053] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the coupling or direct coupling or communication connection shown or discussed may be through some communication interface; the indirect coupling or communication connection between apparatuses or modules may be electrical, mechanical, or other forms.

[0054] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0055] In addition, the functional modules in the various embodiments of the present invention can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0056] 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; and these 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 of amplitude and phase calibration of a dual-polarized measurement probe, characterized by, include: Adjust the relative orientation of the standard antenna and the dual-polarization measurement probe to determine the polarization alignment angle when the calibration polarization direction of the standard antenna is aligned with the first polarization direction of the dual-polarization measurement probe, wherein the first polarization direction is any polarization direction of the dual-polarization measurement probe. The calibration angle is determined based on the polarization alignment angle and the preset angle, and the standard antenna or the dual-polarization measurement probe is driven to rotate around its axis to the calibration angle, wherein the value of the preset angle does not include integer multiples of 90 degrees; While maintaining no relative mechanical movement between the standard antenna and the dual-polarization measurement probe, the first S-parameter between the calibration polarization channel of the standard antenna and the first polarization channel of the dual-polarization measurement probe, and the second S-parameter between the calibration polarization channel of the standard antenna and the second polarization channel of the dual-polarization measurement probe are measured simultaneously. Based on the preset angle, the first S-parameter, and the second S-parameter, the relative amplitude calibration information and relative phase calibration information between the first polarization channel and the second polarization channel of the dual polarization measurement probe are calculated.

2. The method of claim 1, wherein, Adjusting the relative orientation of the standard antenna and the dual-polarization measurement probe to determine the polarization alignment angle when the calibration polarization direction of the standard antenna is aligned with the first polarization direction of the dual-polarization measurement probe includes: The standard antenna and the dual-polarized measurement probe are initially physically aligned to establish an effective signal transmission link; The standard antenna or the dual-polarization measurement probe is controlled to rotate around its axis in preset angle steps. At each rotation angle, the S-parameter between the calibration polarization channel of the standard antenna and the first polarization channel of the dual-polarization measurement probe is measured. The rotation angle corresponding to the maximum amplitude of the S-parameter is determined, and the rotation angle corresponding to the maximum amplitude is used as the polarization alignment angle.

3. The method according to claim 2, characterized in that, After measuring the S-parameters between the calibration polarization channel of the standard antenna and the first polarization channel of the dual-polarization measurement probe at each rotation angle, the method further includes: The S-parameters for each rotation angle are subjected to angle domain interpolation or local curve fitting.

4. The method according to claim 1, characterized in that, The preset angle is 45 degrees.

5. The method according to claim 1, characterized in that, When the standard antenna is a single-polarized antenna, its single polarization direction is the calibration polarization direction; when the standard antenna is a dual-polarized antenna, one of its two polarization directions is fixed as the calibration polarization direction.

6. The method according to claim 1, characterized in that, When the calibration angle has a positional error, the calculation result of the relative phase calibration information is not affected by the positional error.

7. The method according to claim 1, characterized in that, The amplitude and phase calibration method of the dual-polarization measurement probe is applicable to measurement systems in the microwave, millimeter-wave, or terahertz frequency bands.

8. The method according to claim 1, characterized in that, The distance between the standard antenna and the dual-polarized measurement probe is the far-field distance or the near-field distance. The calculation results of the relative amplitude calibration information and the relative phase calibration information are independent of the distance.

9. An amplitude and phase calibration system for a dual-polarization measurement probe, characterized in that, The system for implementing the method as described in any one of claims 1 to 8 comprises: A mechanical positioning and rotation device is used to adjust the relative position and orientation of the standard antenna and the dual-polarized measurement probe; Vector network analyzer, used to measure S-parameters; The control and processing unit is configured to perform relevant control and processing operations.

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