Intelligent testing method and system for isolation performance of multi-port antenna

Abstract

The application relates to the technical field of antenna isolation test, and discloses an intelligent test method and system for multi-port antenna isolation performance, which comprises the following steps: sequentially testing the transmission coefficients of each group of to-be-tested ports of a measured antenna by using a network analyzer, and constructing an S parameter matrix; any group of to-be-tested ports comprises an excitation port and a response port, and the transmission coefficient is the ratio of the power of a scattering wave received by the response port to the power of an incident wave input by the excitation port; based on the S parameter matrix, the isolation of each group of to-be-tested ports at each frequency within the working frequency band of the measured antenna is calculated; the worst isolation of all groups of to-be-tested ports within the working frequency band is identified, and the worst isolation is marked as the isolation of the measured antenna. The application effectively avoids measurement errors and accidental interference, and improves the accuracy and reliability of the isolation test.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of antenna isolation test, in particular to an intelligent test method and system for isolation performance of a multi-port antenna. BACKGROUND

[0002] A plate-shaped antenna system for 6G usually works in a terahertz frequency band, and has a large number of radiation ports and complex coupling between the ports. The isolation degree reflects the mutual interference degree of signals between different ports of the antenna, and insufficient isolation between the ports will cause signal leakage from the transmitting port to the receiving port, resulting in a decrease in receiving sensitivity, signal distortion and an increase in error rate. In a multi-port terahertz plate-shaped antenna system, the isolation performance between any two ports needs to meet the design requirements.

[0003] The current mainstream isolation test scheme generally selects a plurality of discrete frequency points in the working frequency band of the antenna for testing, and takes the minimum isolation value as the final isolation index of the antenna. In actual testing, the isolation value of a single frequency point is easily disturbed by external factors, such as thermal drift of a network analyzer and contact resistance change of a test cable. The existing isolation test method only focuses on the amplitude part of the transmission coefficient and cannot distinguish between real isolation degradation and pseudo-degradation frequency bands caused by measurement errors. In a multi-port terahertz plate-shaped antenna system, the coupling between the ports does not exist in isolation, but often presents a systematic coupling characteristic, that is, isolation degradation occurs simultaneously in the same or similar frequency range for multiple port pairs. Such frequency bands usually correspond to inherent defects of the antenna structure, such as structural resonance and field coupling, and are key factors affecting the overall performance of the antenna. The existing test method uses a mode of testing and independently analyzing each port pair, lacks the ability to analyze the correlation between the couplings between multiple ports, and cannot identify such systematic coupling problems.

[0004] A satellite antenna isolation degree high-precision test system is disclosed in Chinese Patent No. CN111682907B. During the test process of the test link, data interpolation processing is used to focus on the data on the concerned frequency band or frequency point during the test process in a wide frequency band, thereby ensuring the test precision. Filtering processing in the spatial distance is used to suppress environmental interference including environmental electromagnetic reflection and electromagnetic scattering signals, thereby improving the test accuracy. For an antenna having multiple working states, the relationship among the angle, frequency and isolation degree is uniformly reflected, the relationship between the antenna isolation degree and the frequency of the antenna in different states is fully reflected, the completeness of the antenna isolation degree data is improved, and the accuracy of the satellite system radio frequency compatibility evaluation is ensured.

[0005] A patent application with publication number CN106559145A discloses an antenna isolation degree testing system and a testing method. The testing system comprises: a testing mechanical platform, at least two antennas to be tested are installed on the testing mechanical platform; a radio frequency testing unit connected with the at least two antennas to be tested, for measuring a plurality of antenna isolation degree values of the at least two antennas to be tested at different relative positions; and a control unit, a first control end of the control unit is connected with the testing mechanical platform, for controlling the testing mechanical platform to adjust the relative positions of the at least two antennas to be tested according to a preset adjustment rule. The at least two antennas to be tested are installed on the testing mechanical platform, the control unit is used to control the testing mechanical platform to adjust the relative positions of the antennas to be tested, and the radio frequency testing unit is used to measure the antenna isolation degree values of the antennas to be tested at different relative positions, so as to obtain a plurality of sets of test data, and the testing efficiency is improved, which is of great significance for antenna deployment planning.

[0006] The above prior art has the problem proposed in the background: it is unable to distinguish between real isolation degradation and pseudo-degradation bands caused by measurement errors.

[0007] The information disclosed in this background section is only intended to increase the understanding of the general background of the application, and should not be considered as acknowledging or implying in any form that this information constitutes prior art known to those of ordinary skill in the art. SUMMARY

[0008] The technical problem to be solved by the present application is to overcome the defects of the prior art, and to provide an intelligent testing method and system for the isolation performance of a multi-port antenna, to avoid measurement errors and occasional interference, and to improve the accuracy and reliability of isolation degree testing.

[0009] To solve the above technical problems, the present application provides the following technical solutions:

[0010] In one aspect, the present application provides an intelligent testing method for the isolation performance of a multi-port antenna, comprising the following steps:

[0011] The transmission coefficients of each group of to-be-tested ports of the antenna to be tested are tested in sequence by a network analyzer, and an S parameter matrix is constructed; any group of to-be-tested ports comprises an excitation port and a response port, and the transmission coefficient is the ratio of the power of the scattered wave received by the response port to the power of the incident wave input by the excitation port;

[0012] The isolation degrees of each group of to-be-tested ports at each frequency within the working frequency band of the antenna to be tested are calculated based on the S parameter matrix;

[0013] The worst isolation degrees of all groups of to-be-tested ports within the working frequency band are identified, and the worst isolation degrees are marked as the isolation degree of the antenna to be tested.

[0014] As a preferred scheme of the intelligent testing method for the isolation performance of a multi-port antenna provided in the application, the method for testing the transmission coefficient of any group of to-be-tested ports is as follows:

[0015] The excitation port and the response port are respectively connected to two channels of the network analyzer, the network analyzer injects an incident wave of a specified frequency into the excitation port, and receives a scattered wave of the response port, and the transmission coefficient of the group of to-be-tested ports at the corresponding frequency is calculated based on the incident wave and the scattered wave.

[0016] The frequency of the incident wave is changed, and the transmission coefficient of the group of to-be-tested ports at each frequency in the working frequency band is sequentially obtained.

[0017] As a preferred scheme of the intelligent testing method for the isolation performance of a multi-port antenna provided in the application, the S parameter matrix is an N-row and N-column matrix, N is the number of ports of the antenna under test, each S parameter matrix corresponds to a frequency in the working frequency band, and the element in the ith row and jth column of the S parameter matrix represents the transmission coefficient of the group of to-be-tested ports in which the excitation port is the ith port of the antenna under test and the response port is the jth port of the antenna under test.

[0018] For any group of to-be-tested ports, the isolation at any frequency is calculated based on the corresponding transmission coefficient in the corresponding S parameter matrix.

[0019] As a preferred scheme of the intelligent testing method for the isolation performance of a multi-port antenna provided in the application, the method for identifying the worst isolation includes:

[0020] The isolation curve and the phase locus curve of each group of to-be-tested ports are respectively constructed, and the isolation degradation frequency band of each group of to-be-tested ports is extracted based on the isolation curve and the phase locus curve.

[0021] The system degradation frequency band in the isolation degradation frequency band is identified, and each system degradation frequency band is pruned based on the isolation degradation frequency band of different groups of to-be-tested ports.

[0022] The credibility of each system degradation frequency band is calculated based on the isolation degradation frequency band of different groups of to-be-tested ports, and the system degradation frequency band is screened based on the credibility.

[0023] As a preferred scheme of the intelligent testing method for the isolation performance of a multi-port antenna provided in the application, the isolation curve of any group of to-be-tested ports is a curve of the isolation varying with the frequency, each test point in the isolation curve corresponds to a frequency in the working frequency band, the abscissa is the frequency, and the ordinate is the isolation corresponding to the frequency, the phase locus curve of any group of to-be-tested ports is a curve of the phase of the transmission coefficient varying with the frequency, each test point in the phase locus curve corresponds to a frequency in the working frequency band, the abscissa is the frequency, and the ordinate is the phase of the transmission coefficient corresponding to the frequency.

[0024] The method for extracting the isolation degradation frequency band of any group of ports under test is as follows:

[0025] Set the isolation threshold and the isolation fluctuation threshold; calculate the isolation fluctuation value for each test point in the isolation curve; for any test point in the isolation curve, if the isolation is less than the isolation threshold or the isolation fluctuation value is greater than the isolation fluctuation threshold, then mark the corresponding test point as a potential degradation point;

[0026] If there are at least M consecutive potential degradation points on the isolation curve, then the frequency range corresponding to the consecutive potential degradation points is recorded as a potential degradation frequency band; M is a positive integer;

[0027] Extract the corresponding phase trajectory segment from the phase trajectory curve for each potential degraded frequency band; determine whether there is phase jitter in each potential degraded frequency band based on the corresponding phase trajectory segment; mark the potential degraded frequency band without phase jitter as an isolated degraded frequency band.

[0028] As a preferred embodiment of the intelligent testing method for the isolation performance of a multi-port antenna described in this application, the method for calculating the isolation fluctuation value of any test point in the isolation curve is as follows: setting a sliding window; extracting reference test points from the isolation curve through the sliding window; calculating the mean absolute value of the first-order difference of the isolation of each reference test point within the sliding window, as the isolation fluctuation value of the test point;

[0029] The method for determining whether phase jitter exists in any potentially degraded frequency band is as follows:

[0030] Calculate the phase change rate at each test point in the phase trajectory segment corresponding to the potential degradation frequency band;

[0031] The phase fluctuation energy and phase reversal density of the phase trajectory segment are calculated based on the phase change rate; wherein, the phase fluctuation energy is the sum of the squares of the phase change rates of each test point in the phase trajectory segment; the phase reversal density is the ratio of the number of phase reversals in the phase trajectory segment to the number of test points contained in the phase trajectory segment; the number of phase reversals is the total number of times the phase change rate changes from positive to negative or from negative to positive in the phase trajectory segment as the frequency of the test points increases;

[0032] If the phase fluctuation energy of the phase trajectory segment is less than the preset fluctuation energy threshold and the phase reversal density is less than the preset reversal density threshold, then there is no phase jitter in the corresponding potential degradation frequency band.

[0033] As a preferred embodiment of the intelligent testing method for the isolation performance of a multi-port antenna described in this application, the identification of the system degradation frequency band in the isolation degradation frequency band specifically includes:

[0034] calculate the overlap rate of any two isolated degradation frequency bands, and calculate the degradation consensus degree of each isolated degradation frequency band; mark the isolated degradation frequency band with a degradation consensus degree greater than a preset degradation consensus degree threshold as a system degradation frequency band;

[0035] The method for calculating the degradation consensus degree of any isolated degradation frequency band is as follows: a threshold of overlap rate is set; any isolated degradation frequency band is set as a target frequency band; an isolated degradation frequency band with an overlap rate greater than the threshold of overlap rate with the target frequency band is marked as a high overlap frequency band of the target frequency band; and the ratio of the total number of the high overlap frequency bands of the target frequency band to the group number of the to-be-tested ports is calculated as the degradation consensus degree of the target frequency band.

[0036] As a preferred scheme of the intelligent testing method for the isolation performance of the multi-port antenna provided in the application, the method for pruning any segment of the system degradation frequency band is as follows:

[0037] The system coverage rate and the degradation distance of each frequency in the system degradation frequency band are calculated; a threshold of coverage rate and a threshold of degradation distance are set; a frequency with a coverage rate less than the threshold of coverage rate and a degradation distance greater than the threshold of degradation distance is removed from the system degradation frequency band;

[0038] The method for calculating the system coverage rate of any specified frequency in the system degradation frequency band is as follows: the number of the high overlap frequency bands containing the specified frequency in the high overlap frequency bands of the system degradation frequency band is counted, and the total number of the high overlap frequency bands of the system degradation frequency band is divided to obtain the system coverage rate of the specified frequency;

[0039] The method for calculating the degradation distance of any specified frequency in the system degradation frequency band is as follows:

[0040] The isolation degree corresponding to each frequency in each segment of the high overlap frequency band is queried based on the corresponding isolation degree curve; for any segment of the high overlap frequency band of the system degradation frequency band, the frequency corresponding to the minimum isolation degree in the high overlap frequency band is marked as the isolated degradation frequency of the high overlap frequency band;

[0041] The mean value of the isolated degradation frequencies of each segment of the high overlap frequency band is calculated as the reference degradation frequency of the system degradation frequency band; the degradation distance is calculated based on the reference degradation frequency, and the degradation distance of any specified frequency is the absolute value of the difference between the specified frequency and the reference degradation frequency.

[0042] As a preferred scheme of the intelligent testing method for the isolation performance of the multi-port antenna provided in the application, the method for calculating the reliability of any segment of the system degradation frequency band is as follows:

[0043] The phase change rate of each test point in the phase trajectory segment corresponding to the system degradation frequency band is sorted into a phase change vector of the system degradation frequency band;

[0044] The phase change rate of each test point in the phase trajectory segment corresponding to each high-overlapping frequency band of the system degradation frequency band is organized into the phase change vector of the corresponding high-overlapping frequency band.

[0045] The similarity between the phase change vector of the degraded frequency band and the phase change vector of each highly overlapping frequency band is calculated and the weighted average is taken as the confidence of the degraded frequency band. When calculating the weighted average, the weight of any similarity is the overlap rate between the corresponding highly overlapping frequency band and the degraded frequency band.

[0046] The process of filtering system degradation frequency bands specifically includes: setting a confidence threshold; if the confidence of any system degradation frequency band is less than the confidence threshold, then the corresponding system degradation frequency band is removed from the isolated degradation frequency bands.

[0047] Secondly, this application provides an intelligent testing system for the isolation performance of a multi-port antenna, including a testing module, a data processing module, an isolation identification module, and an optimization module; wherein:

[0048] The test module is used to test the transmission coefficient of each group of ports under test of the antenna under test;

[0049] The data processing module constructs an S-parameter matrix based on the transmission coefficients, and constructs the isolation curve and phase trajectory curve for each group of ports under test based on the S-parameter matrix.

[0050] The isolation identification module extracts the isolation degradation frequency band of each group of ports under test based on the isolation degree curve and the phase trajectory curve, and identifies the system degradation frequency band in the isolation degradation frequency band;

[0051] The optimization module is used to trim and filter the degraded frequency bands of each system based on the isolation degraded frequency bands of different groups of ports under test; the data processing module extracts the worst isolation of all groups of ports under test in the working frequency band based on the trimmed and filtered isolation degraded frequency bands, which is used as the isolation of the antenna under test.

[0052] Compared with the prior art, the beneficial effects achieved by this application are as follows:

[0053] The application determines the deterioration frequency band by identifying continuous potential deterioration points, avoids the interference of isolated frequency point extreme fluctuation on the isolation evaluation, filters out the isolation deterioration frequency band without phase jitter, excludes the false minimum value caused by error sources such as probe movement and instrument artifacts, and ensures that the deterioration frequency band conforms to the real electromagnetic coupling rule. For the isolation deterioration frequency band with systematic coupling problem, the frequency points with low coverage of other frequency bands and far away from the minimum isolation of multiple frequency bands are removed, the interference of non-systematic factors such as measurement error and edge effect is excluded; the phase change vector similarity of the system deterioration frequency band and the high overlap frequency band is calculated by the DTW algorithm, the frequency band with low credibility is removed, the non-typical coupling response caused by local transient mismatch and system noise is avoided, and the finally reserved deterioration frequency band has physical consistency and representativeness. BRIEF DESCRIPTION OF DRAWINGS

[0054] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0055] Figure 1 A flow chart of a multi-port antenna isolation performance intelligent test method provided by the application;

[0056] Figure 2 A structural schematic diagram of a multi-port antenna isolation performance intelligent test system provided by the application;

[0057] Figure 3 A flow chart of a method for identifying the worst isolation provided by the application;

[0058] Figure 4 A device connection diagram for testing the transmission coefficient of any group of to-be-tested ports provided by the application. DETAILED DESCRIPTION

[0059] The technical solutions of the application will be described in detail below with the help of the drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solutions of the application, rather than limitations of the technical solutions of the application. In the case of no conflict, the technical features in the embodiments and the embodiments can be combined with each other.

[0060] Embodiment 1

[0061] This embodiment introduces a multi-port antenna isolation performance intelligent test method, which refers to Figure 1 The method comprises the following steps:

[0062] The transmission coefficient of each group of to-be-tested ports of the measured antenna is tested in sequence by the network analyzer, and an S parameter matrix is constructed; any group of to-be-tested ports includes an excitation port and a response port, and the transmission coefficient is the ratio of the power of the scattered wave received by the response port to the power of the incident wave input by the excitation port;

[0063] The measured antenna has multiple ports, and any two ports form a group of to-be-tested ports; all ports are traversed, and the port numbers of the excitation port and the response port included in each group of to-be-tested ports are recorded; when the transmission coefficient is tested, the measured antenna is placed in an anechoic chamber, each group of to-be-tested ports is tested in sequence, and the transmission coefficients of different groups of to-be-tested ports are collected to construct an S parameter matrix. The inner wall of the anechoic chamber is covered with a wave-absorbing material, which can absorb electromagnetic signals and reduce reflected signal interference, providing an environment similar to free space for isolation testing to ensure the accuracy of the test results.

[0064] Referring to Figure 4 , the method for testing the transmission coefficient of any group of to-be-tested ports is as follows:

[0065] The excitation port and the response port are respectively connected to two channels of the network analyzer by the network tester; the network analyzer injects an incident wave of a specified frequency into the excitation port and receives the scattered wave of the response port; and the transmission coefficient of the to-be-tested port group at the corresponding frequency is calculated based on the incident wave and the scattered wave.

[0066] The frequency of the incident wave is changed, and the transmission coefficient of the to-be-tested port group at each frequency within the working frequency band is obtained in sequence.

[0067] The transmission coefficient is a complex number, including an amplitude part and a phase part. The amplitude part of the transmission coefficient is used to calculate the isolation; and the phase part reflects the reflection, resonance and other effect information of the signal transmission path between the ports.

[0068] When testing the transmission coefficient of any group of to-be-tested ports, the excitation port and the response port are connected to two channels of the network analyzer, and the remaining non-test ports are all connected to a matching load to prevent the signal of the non-test port from being reflected back into the antenna and interfering with the ongoing test.

[0069] The S parameter matrix is an N-by-N matrix, where N is the number of ports of the measured antenna; each S parameter matrix corresponds to a frequency in the working frequency band, that is, all transmission coefficients in the same S parameter matrix are triggered and calculated by the incident wave of the same frequency; and the element in the ith row and jth column of the S parameter matrix represents the transmission coefficient of the to-be-tested port group with the excitation port being the ith port of the measured antenna and the response port being the jth port of the measured antenna.

[0070] Based on the S parameter matrix, the isolation of each group of to-be-tested ports at each frequency within the working frequency band of the measured antenna is calculated;

[0071] For any group of to-be-tested ports, the isolation at any frequency is calculated based on the corresponding transmission coefficient in the corresponding S parameter matrix; the formula is as follows:

[0072] ;

[0073] wherein, represents the isolation of the group of to-be-tested ports at frequency f; represents the transmission coefficient of the group of to-be-tested ports at frequency f; represents the amplitude of the transmission coefficient .

[0074] The transmission coefficient reflects the coupling strength of the signal between the excitation port and the response port; the greater the transmission coefficient, the more signal leakage, the greater the interference of the excitation port on the response port, that is, the worse the isolation performance between the ports; the amplitude of the transmission coefficient is converted to decibel value as the isolation by the above formula, which is convenient for quantitative comparison and performance determination.

[0075] The worst isolation of all groups of to-be-tested ports in the working frequency band is identified, and the worst isolation is marked as the isolation of the measured antenna.

[0076] In a multi-port antenna system, low isolation between any pair of ports will affect the performance of the entire antenna system. Therefore, the worst isolation of all groups of to-be-tested ports in the working frequency band is selected as the isolation of the to-be-tested antenna, so that the isolation of the to-be-tested antenna can represent the worst isolation condition between the ports of the entire antenna system, and can be used to evaluate whether the anti-interference performance of the antenna system meets the requirements.

[0077] Referring to Figure 3 , the method of identifying the worst isolation comprises:

[0078] The isolation curve and the phase locus curve of each group of to-be-tested ports are respectively constructed; the isolation degradation frequency band of each group of to-be-tested ports is extracted based on the isolation curve and the phase locus curve;

[0079] The isolation curve of any group of to-be-tested ports is a curve of isolation varying with frequency; each test point in the isolation curve corresponds to a frequency in the working frequency band, the horizontal coordinate is the frequency, and the vertical coordinate is the isolation corresponding to the frequency; the phase locus curve of any group of to-be-tested ports is a curve of the phase of the transmission coefficient varying with frequency; each test point in the phase locus curve corresponds to a frequency in the working frequency band, the horizontal coordinate is the frequency, and the vertical coordinate is the phase of the transmission coefficient corresponding to the frequency;

[0080] For any group of to-be-tested ports, the transmission coefficient thereof at the corresponding frequency is queried through the corresponding S parameter matrix, the isolation thereof at the corresponding frequency is calculated through the amplitude of the transmission coefficient, and the phase of the transmission coefficient at the corresponding frequency is recorded; the S parameter matrix corresponding to each frequency in the working frequency band is traversed, the isolation and the phase of the transmission coefficient of the group of to-be-tested ports are obtained with respect to the change of the frequency, and the isolation curve and the phase trajectory curve thereof are drawn respectively.

[0081] The method for extracting the isolation degradation frequency band of any group of to-be-tested ports is as follows:

[0082] The isolation threshold and the isolation fluctuation threshold are set; the isolation fluctuation value of each test point in the isolation curve is calculated; for any test point in the isolation curve, if the isolation is less than the isolation threshold or the isolation fluctuation value is greater than the isolation fluctuation threshold, the corresponding test point is marked as a potential degradation point;

[0083] If there are at least M consecutive potential degradation points on the isolation curve, the frequency range corresponding to the consecutive potential degradation points is recorded as a potential degradation frequency band; M is a positive integer;

[0084] The corresponding phase trajectory section is intercepted from the phase trajectory curve for each potential degradation frequency band; whether each potential degradation frequency band has phase jitter is judged based on the corresponding phase trajectory section; the potential degradation frequency band without phase jitter is marked as an isolation degradation frequency band.

[0085] The method for calculating the isolation fluctuation value of any test point in the isolation curve is as follows: a sliding window is set; the reference test points are intercepted from the isolation curve for the test point through the sliding window; the absolute value average of the first-order difference value of the isolation of each reference test point in the sliding window is calculated as the isolation fluctuation value of the test point.

[0086] Optionally, the sliding window with a length of m is set, that is, m reference test points are intercepted from the isolation curve for any test point, and the test point is preferably taken as the midpoint of the sliding window for interception. The first-order difference value of the isolation of any reference test point is the difference between the isolation thereof and the isolation of the previous test point adjacent thereto in the isolation curve; the greater the absolute value average of the first-order difference value of the isolation of all reference test points in the sliding window, the more obvious the isolation fluctuation of the corresponding test point.

[0087] The traditional isolation test scheme directly extracts the minimum value of the isolation in the working frequency band. However, the isolation of a single frequency point is easily affected by device errors, thermal drift and the like, so that the minimum value of the isolation cannot correspond to the real energy coupling, causing the distortion of the isolation judgment of the antenna. In the terahertz frequency band, the isolation between the ports varies irregularly with the frequency, and the frequency band reflecting the electromagnetic coupling strength is usually not only one frequency point, but also presents a regional disturbance trend in the frequency. The application can avoid the deviation of the overall isolation evaluation caused by the extreme fluctuation of the isolated frequency point, eliminate the accidental isolation abnormal points caused by measurement errors, instrument jitter and the like, so that the test result is more in line with the bandwidth characteristics of the terahertz communication.

[0088] For any potential degradation frequency band, the frequency range corresponding to the phase trajectory segment intercepted for the potential degradation frequency band is the frequency range covered by the potential degradation frequency band.

[0089] The method for judging whether any potential degradation frequency band has phase jitter is as follows:

[0090] The phase change rate of each test point in the phase trajectory segment corresponding to the potential degradation frequency band is calculated.

[0091] For any test point in the phase trajectory segment, the phase difference between the test point and the adjacent previous test point in the phase trajectory curve is calculated, and the ratio of the phase difference to the phase thereof is calculated to obtain the phase change rate.

[0092] The phase fluctuation energy and the phase inversion density of the phase trajectory segment are calculated based on the phase change rate. The phase fluctuation energy is the sum of squares of the phase change rates of each test point in the phase trajectory segment. The phase inversion density is the ratio of the number of phase inversions in the phase trajectory segment to the number of test points included in the phase trajectory segment. The number of phase inversions is the total number of times that the phase change rate changes from positive to negative or from negative to positive as the frequency of the test point increases in the phase trajectory segment.

[0093] If the phase fluctuation energy of the phase trajectory segment is less than a preset fluctuation energy threshold, and the phase inversion density is less than a preset inversion density threshold, then the corresponding potential degradation frequency band does not have phase jitter.

[0094] The traditional isolation test method ignores the phase information of the transmission coefficient. The main coupling path between the antenna ports usually has a continuous and slowly varying phase evolution. If the phase jitter exists, it indicates that the energy transmission path of the corresponding frequency band is unstable or mixed with non-main mode responses, and there are error sources such as probe movement, instrument artifacts and inductive coupling. The application can avoid introducing the pseudo-minimum value of the isolation by screening the isolation degradation frequency band through the phase trajectory segment, and improve the credibility of the isolation degradation frequency band.

[0095] identify a system deterioration frequency band in the isolation deterioration frequency bands, and prune each system deterioration frequency band based on the isolation deterioration frequency bands of different groups of to-be-tested ports;

[0096] The identifying the system deterioration frequency band in the isolation deterioration frequency bands specifically comprises:

[0097] Calculate the overlap rate of any two isolation deterioration frequency bands, and calculate the deterioration consensus degree of each isolation deterioration frequency band; mark the isolation deterioration frequency band with a deterioration consensus degree greater than a preset deterioration consensus degree threshold as a system deterioration frequency band;

[0098] The method for calculating the deterioration consensus degree of any isolation deterioration frequency band is as follows: set an overlap rate threshold; set any isolation deterioration frequency band as a target frequency band; mark the isolation deterioration frequency band with an overlap rate greater than the overlap rate threshold as a high overlap frequency band of the target frequency band; calculate the ratio of the total number of the high overlap frequency bands of the target frequency band to the number of groups of to-be-tested ports as the deterioration consensus degree of the target frequency band.

[0099] Optionally, the overlap rate of any two isolation deterioration frequency bands is represented by the intersection-over-union ratio, that is, the ratio of the length of the frequency band corresponding to the intersection of the two isolation deterioration frequency bands to the length of the frequency band corresponding to the union.

[0100] The method for pruning any system deterioration frequency band is as follows:

[0101] Calculate the system coverage rate and the deterioration distance of each frequency in the system deterioration frequency band; set a coverage rate threshold and a deterioration distance threshold; remove the frequency with a system coverage rate less than the coverage rate threshold and a deterioration distance greater than the deterioration distance threshold from the system deterioration frequency band;

[0102] The method for calculating the system coverage rate of any specified frequency in the system deterioration frequency band is as follows: count the number of high overlap frequency bands containing the specified frequency in the high overlap frequency bands of the system deterioration frequency band, and divide the number by the total number of the high overlap frequency bands of the system deterioration frequency band to obtain the system coverage rate of the specified frequency.

[0103] The method for calculating the deterioration distance of any specified frequency in the system deterioration frequency band is as follows:

[0104] Query the isolation degree corresponding to each frequency in each high overlap frequency band based on the corresponding isolation degree curve; for any high overlap frequency band of the system deterioration frequency band, mark the frequency corresponding to the minimum isolation degree in the high overlap frequency band as the isolation deterioration frequency of the high overlap frequency band.

[0105] Calculate the mean value of the isolation deterioration frequencies of each high overlap frequency band as the reference deterioration frequency of the system deterioration frequency band; calculate the deterioration distance based on the reference deterioration frequency, and the deterioration distance of any specified frequency is the absolute value of the difference between the specified frequency and the reference deterioration frequency.

[0106] In the terahertz frequency band, the coupling between multiple ports is usually not isolated, but often occurs in a narrow frequency band with structural resonance characteristics. The system degradation frequency band represents the isolation performance fluctuation of the multi-port path in the same frequency band or adjacent frequency band, and the frequency band has systematic coupling problems such as structural resonance, field coupling, etc. The present application ensures that the isolation degradation frequency band with system coupling follows the physical constraints by pruning the frequency points with low system coverage and large degradation distance in the system degradation frequency band, and can eliminate false isolation degradation caused by measurement errors, edge effects or non-systematic transient factors.

[0107] The credibility of each system degradation frequency band is calculated based on the isolation degradation frequency bands of different groups of to-be-tested ports; and the system degradation frequency bands are screened based on the credibility.

[0108] The method for calculating the credibility of any system degradation frequency band is as follows:

[0109] The phase change rate of each test point in the phase trajectory segment corresponding to the system degradation frequency band is sorted into a phase change vector of the system degradation frequency band.

[0110] The phase change rate of each test point in the phase trajectory segment corresponding to each high overlap frequency band of the system degradation frequency band is sorted into a phase change vector of the corresponding high overlap frequency band.

[0111] The similarity between the phase change vector of the system degradation frequency band and the phase change vector of each high overlap frequency band is calculated respectively and the weighted mean is taken as the credibility of the system degradation frequency band. When calculating the weighted mean, the weight of any similarity is the overlap rate of the corresponding high overlap frequency band and the system degradation frequency band.

[0112] The screening of the system degradation frequency band specifically includes: setting a credibility threshold; if the credibility of any system degradation frequency band is less than the credibility threshold, the corresponding system degradation frequency band is eliminated in the isolation degradation frequency band. The eliminated system degradation frequency band no longer participates in the identification and extraction of the worst isolation.

[0113] The present embodiment preferably arranges the phase change rate in the order of the frequency corresponding to the test point from small to large to obtain the phase change vector of the system degradation frequency band or any high overlap frequency band, and calculates the similarity between the phase change vectors by DTW (Dynamic Time Warping).

[0114] When there is a systematic coupling problem such as structural resonance in a certain frequency range, the phases of multiple groups of to-be-tested ports in the frequency range show consistent or similar change trends. If the phase change of the system degradation frequency band is low in similarity with the high overlap frequency band, that is, the credibility is low, there are errors such as non-main mode phase response caused by local transient mismatch, response time delay drift, system noise or pseudo response caused by non-ideal coupling path, and the phase change trend conforms to the coupling mode of the frequency range. The isolation degree corresponding to the non-typical and non-reproducible coupling mechanism does not have representativeness. The embodiment eliminates the system degradation frequency band with low credibility through the phase change condition, which helps to improve the overall credibility and physical consistency of the isolation degree evaluation result.

[0115] The minimum value of the isolation degree corresponding to each frequency in all isolation degradation frequency bands of each group of to-be-tested ports is extracted as the worst isolation degree.

[0116] After pruning and screening the system degradation frequency bands in the isolation degradation frequency bands, high-credibility isolation degradation frequency bands are obtained; the isolation degrees of the test points corresponding to each frequency in the isolation degree curve in the high-credibility isolation degradation frequency bands are counted, and the minimum isolation degree therein is extracted as the worst isolation degree.

[0117] Embodiment 2

[0118] This embodiment is the second embodiment of the present application; based on the same inventive concept as embodiment 1, referring to Figure 2 This embodiment introduces an intelligent test system for the isolation performance of a multi-port antenna, which includes a test module, a data processing module, an isolation identification module, and an optimization module; wherein:

[0119] The test module is used to test the transmission coefficients of each group of to-be-tested ports of the measured antenna; the test module includes a network analyzer and provides anechoic darkroom for the measured antenna, providing an environment similar to free space for testing to ensure the accuracy of the test results; when measuring the transmission coefficients of any group of to-be-tested ports, the remaining ports are connected to a matching load.

[0120] The data processing module constructs an S parameter matrix based on the transmission coefficients, and constructs an isolation degree curve and a phase trajectory curve for each group of to-be-tested ports based on the S parameter matrix; each S parameter matrix corresponds to a frequency in the working frequency band, and is used to represent the transmission coefficients between different groups of to-be-tested ports under the excitation of incident waves at the corresponding frequency; the module calculates the isolation degree of each group of to-be-tested ports through the amplitude of the transmission coefficient; the isolation degree curve and the phase trajectory curve respectively represent the change of the isolation degree and the phase of the corresponding group of to-be-tested ports with frequency.

[0121] The isolation identification module extracts the isolation degradation frequency band of each group of to-be-tested ports based on the isolation curve and the phase trajectory curve, and identifies the system degradation frequency band in the isolation degradation frequency band. The module is configured with a first identification strategy and a second identification strategy. The first identification strategy includes marking a potential degradation frequency band by identifying a potential degradation point on the isolation curve, and determining whether there is phase jitter in each potential degradation frequency band based on the phase trajectory curve. The potential degradation frequency band without phase jitter is marked as an isolation degradation frequency band. The second identification strategy includes calculating the degradation consensus degree of each isolation degradation frequency band, and marking the isolation degradation frequency band with a degradation consensus degree greater than a preset degradation consensus degree threshold as a system degradation frequency band.

[0122] The optimization module is used to prune and screen each system degradation frequency band based on the isolation degradation frequency band of different groups of to-be-tested ports. The data processing module extracts the worst isolation of all groups of to-be-tested ports in the working frequency band based on the pruned and screened isolation degradation frequency band, as the isolation of the measured antenna. The optimization module is configured with a first adjustment strategy and a second adjustment strategy. The first adjustment strategy includes calculating the system coverage rate and degradation distance of each frequency in the system degradation frequency band, and removing the frequency with a system coverage rate less than a coverage rate threshold and a degradation distance greater than a degradation distance threshold from the system degradation frequency band. The second adjustment strategy includes calculating the credibility of each system degradation frequency band, and removing the system degradation frequency band with a credibility less than a credibility threshold.

[0123] The specific function implementation of each module is described in the related content of the intelligent test method for the isolation performance of a multi-port antenna in Embodiment 1, which is not repeated here.

[0124] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can be in the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can be in the form of a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

[0125] The embodiments of the present application are described above in combination with the drawings, but the present application is not limited to the above specific embodiments, which are only illustrative and not limiting. Those skilled in the art can make many forms without departing from the purpose and scope of the present application under the inspiration of the present application, which are all within the protection of the present application.

Claims

1. A method for intelligently testing the isolation performance of a multi-port antenna, the method comprising: The method comprises the following steps: ​ testing transmission coefficients of each group of to-be-tested ports of the antenna under test in sequence by a network analyzer, and constructing an S parameter matrix; any group of to-be-tested ports comprises an excitation port and a response port, and the transmission coefficient is a ratio of power of a scattering wave received by the response port to power of an incident wave input by the excitation port; calculating isolation degrees of each group of to-be-tested ports at each frequency in a working frequency band of the antenna under test based on the S parameter matrix; identifying worst isolation degrees of all groups of to-be-tested ports in the working frequency band, and marking the worst isolation degrees as isolation degrees of the antenna under test; the method for identifying the worst isolation degrees comprises: constructing an isolation degree curve and a phase locus curve of each group of to-be-tested ports respectively; extracting an isolation degradation frequency band of each group of to-be-tested ports based on the isolation degree curve and the phase locus curve; identifying system degradation frequency bands in the isolation degradation frequency band, and pruning each system degradation frequency band based on isolation degradation frequency bands of different groups of to-be-tested ports; calculating a credibility of each system degradation frequency band based on isolation degradation frequency bands of different groups of to-be-tested ports; and screening the system degradation frequency band based on the credibility; the isolation degree curve of any group of to-be-tested ports is a curve of isolation degree changing with frequency; each test point in the isolation degree curve corresponds to a frequency in the working frequency band, the abscissa is the frequency, and the ordinate is the isolation degree corresponding to the frequency; the phase locus curve of any group of to-be-tested ports is a curve of phase of the transmission coefficient changing with frequency; each test point in the phase locus curve corresponds to a frequency in the working frequency band, the abscissa is the frequency, and the ordinate is the phase of the transmission coefficient corresponding to the frequency; the method for extracting the isolation degradation frequency band of any group of to-be-tested ports is as follows: setting an isolation degree threshold and an isolation fluctuation threshold; calculating an isolation fluctuation value of each test point in the isolation degree curve; for any test point in the isolation degree curve, if the isolation degree is less than the isolation degree threshold or the isolation fluctuation value is greater than the isolation fluctuation threshold, the corresponding test point is marked as a potential degradation point; if there are at least M consecutive potential degradation points on the isolation degree curve, a frequency range corresponding to the consecutive potential degradation points is recorded as a potential degradation frequency band; M is a positive integer; cutting a corresponding phase locus segment from the phase locus curve for each potential degradation frequency band; judging whether each potential degradation frequency band has phase jitter based on the corresponding phase locus segment; and marking the potential degradation frequency band without phase jitter as an isolation degradation frequency band; the method for pruning any system degradation frequency band is as follows: calculating a system coverage rate and a degradation distance of each frequency in the system degradation frequency band; setting a coverage rate threshold and a degradation distance threshold; and removing a frequency with a system coverage rate less than the coverage rate threshold and a degradation distance greater than the degradation distance threshold from the system degradation frequency band; the calculation method of the system coverage rate of any specified frequency in the system degradation frequency band is as follows: counting a number of high-overlapping frequency bands containing the specified frequency in the high-overlapping frequency bands of the system degradation frequency band, and dividing the number by a total number of the high-overlapping frequency bands of the system degradation frequency band to obtain the system coverage rate of the specified frequency; the calculation method of the degradation distance of any specified frequency in the system degradation frequency band is as follows: query the isolation degree corresponding to each frequency in each high-overlap frequency band based on the corresponding isolation degree curve; for any high-overlap frequency band of the system degradation frequency band, mark the frequency corresponding to the minimum isolation degree in the high-overlap frequency band as the isolation degradation frequency of the high-overlap frequency band; calculate the mean value of the isolation degradation frequencies of each high-overlap frequency band as the reference degradation frequency of the system degradation frequency band; calculate the degradation distance based on the reference degradation frequency, and the degradation distance of any specified frequency is the absolute value of the difference between the specified frequency and the reference degradation frequency; the method for calculating the reliability of any system degradation frequency band is as follows: arrange the phase change rates of each test point in the phase trajectory segment corresponding to the system degradation frequency band into a phase change vector of the system degradation frequency band; arrange the phase change rates of each test point in the phase trajectory segment corresponding to each high-overlap frequency band of the system degradation frequency band into a phase change vector of the corresponding high-overlap frequency band; calculate the similarity between the phase change vector of the system degradation frequency band and the phase change vector of each high-overlap frequency band respectively and take the weighted mean value as the reliability of the system degradation frequency band; when calculating the weighted mean value, the weight of any similarity is the overlap rate of the corresponding high-overlap frequency band and the system degradation frequency band; the screening of the system degradation frequency bands, specifically includes: setting a reliability threshold; if the reliability of any system degradation frequency band is less than the reliability threshold, the corresponding system degradation frequency band is eliminated in the isolation degradation frequency band.

2. The intelligent testing method of multi-port antenna isolation performance according to claim 1, characterized in that: the method for testing the transmission coefficients of any group of to-be-tested ports is as follows: connect the excitation port and the response port to two channels of the network analyzer respectively through the network tester; inject incident waves of a specified frequency into the excitation port through the network analyzer, and receive scattered waves of the response port; calculate the transmission coefficient of the to-be-tested port group at the corresponding frequency based on the incident waves and the scattered waves; change the frequency of the incident waves to obtain the transmission coefficient of the to-be-tested port group at each frequency within the working frequency band in turn.

3. The method of claim 2, wherein: the plurality of ports are associated with a plurality of bands; and the plurality of bands are associated with a plurality of frequency ranges. the S parameter matrix is an N-row and N-column matrix, N is the number of ports of the measured antenna; each S parameter matrix corresponds to a frequency in the working frequency band; the element in the ith row and jth column of the S parameter matrix represents the transmission coefficient of the to-be-tested port group when the excitation port is the ith port of the measured antenna and the response port is the jth port of the measured antenna; for any group of to-be-tested ports, the isolation degree at any frequency is calculated based on the corresponding transmission coefficient in the corresponding S parameter matrix.

4. The method of claim 3, wherein: the method for calculating the isolation fluctuation value of any test point in the isolation degree curve is as follows: setting a sliding window; the reference test points of the test point are intercepted from the isolation degree curve through the sliding window; calculate the absolute value mean of the first-order difference value of the isolation degree of each reference test point in the sliding window as the isolation fluctuation value of the test point; the method for judging whether any potential degradation frequency band has phase jitter is as follows: calculate the phase change rate of each test point in the phase trajectory segment corresponding to the potential degradation frequency band; Calculate a phase fluctuation energy and a phase inversion density of the phase trajectory segment based on the phase change rate; wherein the phase fluctuation energy is a sum of squares of the phase change rate of each test point in the phase trajectory segment; the phase inversion density is a ratio of a phase inversion number of the phase trajectory segment to a number of test points contained in the phase trajectory segment; the phase inversion number is a total number of times that the phase change rate changes from positive to negative or from negative to positive along with an increasing frequency of the test points in the phase trajectory segment; If the phase fluctuation energy of the phase trajectory segment is less than a preset fluctuation energy threshold, and the phase inversion density is less than a preset inversion density threshold, then the corresponding potential degraded frequency band does not exist phase jitter.

5. The method of claim 4, wherein: the plurality of ports are associated with a plurality of bands; and the plurality of bands are associated with a plurality of frequency ranges. The system degraded frequency band in the isolated degraded frequency band is identified, and specifically includes: Calculate an overlap rate of any two isolated degraded frequency bands, and calculate a degradation consensus degree of each isolated degraded frequency band; mark the isolated degraded frequency band with a degradation consensus degree greater than a preset degradation consensus degree threshold as a system degraded frequency band; The method for calculating the degradation consensus degree of any isolated degraded frequency band is as follows: set an overlap rate threshold; set any isolated degraded frequency band as a target frequency band; mark the isolated degraded frequency band with an overlap rate greater than the overlap rate threshold as a high overlap frequency band of the target frequency band; calculate a ratio of a total number of the high overlap frequency bands of the target frequency band to a group number of the to-be-tested ports as the degradation consensus degree of the target frequency band.

6. An intelligent test system for multi-port antenna isolation performance, which is used to implement the intelligent test method for multi-port antenna isolation performance according to any one of claims 1-5, characterized in that: The method comprises a test module, a data processing module, an isolation identification module, and an optimization module; wherein: The test module is used to test a transmission coefficient of each group of to-be-tested ports of the tested antenna; The data processing module is used to construct an S parameter matrix based on the transmission coefficient, and construct an isolation degree curve and a phase trajectory curve of each group of to-be-tested ports based on the S parameter matrix; The isolation identification module is used to extract an isolated degraded frequency band of each group of to-be-tested ports based on the isolation degree curve and the phase trajectory curve, and identify a system degraded frequency band in the isolated degraded frequency band; The optimization module is used to prune and screen each system degraded frequency band based on the isolated degraded frequency bands of different groups of to-be-tested ports; and the data processing module is used to extract a worst isolation degree of all groups of to-be-tested ports in a working frequency band as an isolation degree of the tested antenna based on the pruned and screened isolated degraded frequency bands.

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