Passive antenna array beam forming test method and system

Abstract

The invention provides a passive antenna array beam forming test method and system, and relates to the technical field of beam forming test. According to the method, channel baseline parameters are established in a silencing environment, frequency hopping and channel switching are combined to realize multi-frequency-point synchronous sampling, a reference source and self-polling data are utilized to calculate a mutual coupling correction matrix and a feeder line consistency factor, and weight projection and equivalent aperture field generation are completed without changing physical wiring conditions; further extracting a main lobe direction, a beam width, a side lobe level and a scanning consistency index through far field transformation, and unwrapping and smoothing a frequency-point-crossing phase result; and meanwhile, generating a unique traceability identifier, establishing full-link association between a test condition and a result, and outputting a criterion conclusion. According to the method, the accuracy, efficiency and traceability of passive array beam testing are improved.

Description

Technical Field

[0001] This invention relates to the field of beamforming testing technology, and in particular to a passive antenna array beamforming testing method and system. Background Technology

[0002] Current beamforming tests for antenna arrays largely rely on anechoic chamber far-field turntable testing or near-field scanning and re-transformation methods. A typical procedure involves port-by-port feeding or sequential switching, measuring amplitude and phase using a vector network analyzer, and then reconstructing the main lobe and side lobe indices at the target frequency using preset weights. While these methods utilize mature equipment, they suffer from long testing cycles, are prone to phase drift due to port switching, and are highly sensitive to mutual coupling, feeder inconsistencies, and turntable positioning errors, resulting in insufficient repeatability and comparability.

[0003] With the widespread adoption of large-scale, multi-band, wide-angle scanning passive arrays, testing requirements are shifting from type verification of single-frequency points and single main lobes to process evaluation of multi-frequency broadband, consistency, and environmental robustness. The industry is gradually adopting multi-channel synchronous acquisition, reference phase links, and fast frequency scanning, combined with mutual coupling correction matrices and cell aperture models for rapid reconstruction under multiple operating conditions, and introducing edge computing to complete data denoising, phase unwrapping, and automatic criterion determination.

[0004] However, the existing solutions still have shortcomings: First, the channel phase reference and the turntable mechanical zero position are not unified, and there is a lack of traceable phase baselines for cross-channel and cross-frequency comparisons; second, the inconsistency between mutual coupling and feeder is mostly corrected based on experience, making it difficult to make self-consistent estimates within a single test; third, the test results lack a unified correlation with weights, attitude, frequency points, and calibration parameters, making it difficult to verify and trace back, which affects the batch consistency release. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, the purpose of this invention is to provide a passive antenna array beamforming test method and system. Through innovative designs in five aspects—channel baseline correction, frequency jump sampling, mutual coupling removal, far-field transformation, and traceability management—the accuracy, efficiency, and traceability of passive antenna array beamforming tests are significantly improved.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] A passive antenna array beamforming test method includes:

[0008] A reference calibration source and a reference receiving link are deployed in an anechoic environment. The amplitude and phase offset of each measurement channel are estimated under a unified time reference to obtain the channel baseline parameters.

[0009] Based on the frequency jump sequence and channel switching strategy, synchronous sampling is performed on each port of the array to obtain amplitude and phase observations of multiple frequency points, and the attitude angle, reference source status and frequency point number are recorded.

[0010] Based on the reference calibration source excitation and array self-polling data, the mutual coupling correction matrix and feeder amplitude consistency factor are calculated, and the observations at each port are decoupled and normalized.

[0011] Without changing the physical wiring, the amplitude and phase weights of the target beam are projected onto the calibrated port observation to obtain the equivalent weighted array equivalent port field.

[0012] The equivalent aperture field is transformed into a far-field field to obtain the main lobe direction, beamwidth, sidelobe level and scanning consistency indicators, and the cross-frequency point results are unwrapped and smoothed.

[0013] Generate a unique traceability identifier for each test, establish and store the association between weights, attitude, frequency sequence, channel baseline parameters, mutual coupling correction matrix and calculated indicators, and output the pass conclusion and anomaly location information according to preset criteria.

[0014] Preferably, a reference calibration source and a reference receiving link are deployed in an anechoic environment, and the amplitude and phase offset of each measurement channel are estimated under a unified time reference to obtain the channel baseline parameters, including:

[0015] A reference calibration source with stable amplitude and phase is placed in the far-field reference direction in the anechoic chamber, and the output power and frequency of the reference calibration source are kept constant within the target test frequency band to serve as a reference signal source for amplitude and phase.

[0016] A reference receiving link equivalent to the antenna port is introduced in each measurement channel. The reference receiving link includes an equal-length feed line and an identical gain amplifier to ensure hardware consistency between different channels.

[0017] The receiving results of the reference calibration source signal in each channel are acquired simultaneously under a unified time reference, and the sampling time is synchronized and corrected using an external clock to eliminate timing differences between channels.

[0018] The received results of each channel are compared with the theoretical amplitude and phase of the reference calibration source. The amplitude gain bias and phase offset of each channel are calculated and stored as channel baseline parameters.

[0019] Preferably, the received results of each channel are compared with the theoretical amplitude and phase of the reference calibration source, and the amplitude gain bias and phase offset of each channel are calculated respectively. The amplitude gain bias and phase offset are stored as channel baseline parameters, including:

[0020] Based on the rated transmit power and spatial geometric path length of the reference calibration source, and combined with the free space loss model, the theoretical received amplitude and theoretical received phase at the target frequency are calculated.

[0021] Under a unified time reference, the reception results of each channel are analyzed to obtain the measured received amplitude and measured received phase, which are used as the measured results.

[0022] The measured results are compared with the theoretical results, and the amplitude gain bias and phase offset of each channel are calculated using the following formula:

[0023] Among them, G ch Let be the amplitude gain bias of the ch-th channel. A represents the measured received amplitude of the ch-th channel. theo For the theoretical received amplitude, Δφ ch Let be the phase offset of the ch-th channel. φ is the measured received phase of the ch-th channel. theo The theoretical receiving phase;

[0024] The calculated amplitude gain offset and phase offset are bound according to the channel number, frequency point number and time window identifier, and written into the channel baseline parameter table.

[0025] Preferably, based on the frequency jump sequence and channel switching strategy, synchronous sampling is performed on each port of the array to obtain amplitude and phase observations at multiple frequency points, and the attitude angle, reference source state, and frequency point number are recorded, including:

[0026] According to the preset frequency switching sequence, the operating frequency of the transmitter or receiver is switched sequentially, and the dwell time of each frequency point meets the stability requirements of the sampling.

[0027] At each frequency point, each array port is activated sequentially or in parallel according to the channel switching strategy, so that each port can obtain amplitude and phase response under the same frequency point conditions.

[0028] Under a unified time reference, the received signal of the activated port is synchronously sampled in terms of amplitude and phase. The sampling process is aligned with the external clock or trigger signal to ensure that the cross-channel results have strict time consistency.

[0029] When sampling each frequency point and channel, the observation results are bound with the corresponding attitude angle, reference source operating status, and frequency point number to form a structured observation entry.

[0030] Preferably, the channel switching strategy includes:

[0031] Within one frequency transition cycle, each array port is activated sequentially according to its port number, ensuring all ports complete observations at the same frequency; or

[0032] When multi-channel parallel acquisition capability is available, the array port is divided into several parallel groups, and the parallel groups are sampled simultaneously in each frequency point to shorten the test time. The sequential activation and group parallel methods can be selected or combined according to the test scale and equipment capability to balance channel consistency and test efficiency.

[0033] Preferably, based on the reference calibration source excitation and array self-polling data, the mutual coupling correction matrix and feeder amplitude-phase consistency factor are calculated, and the observations at each port are decoupled and normalized, including:

[0034] Under the fixed-direction excitation of the reference calibration source, each array port is sequentially sampled and the array self-polling data is acquired to obtain the measured amplitude and phase observations of each port.

[0035] The measured results of each port under the excitation of the reference calibration source are compared with the output of the theoretical aperture model. The amplitude gain factor and phase offset factor of each port are extracted, and the amplitude gain factor and the phase offset factor are summarized into the feeder amplitude and phase consistency factor, which is used to characterize the differences between the feeder and hardware path between ports.

[0036] In the array self-polling data, the response amplitude and phase characteristics of adjacent ports are analyzed when a certain port is excited, the coupling relationship between each port is established, and the parameters of the coupling relationship are arranged and combined to form a mutual coupling correction matrix;

[0037] The measured results of each port are inverted using the mutual coupling correction matrix to eliminate the influence of mutual coupling interference. The decoupled results are then normalized according to the feeder amplitude-phase consistency factor so that the amplitude and phase of all ports are expressed under a unified reference.

[0038] Preferably, without changing the physical wiring, the amplitude and phase weights of the target beam are projected onto the calibrated port observations to obtain the equivalent weighted array equivalent port field, including:

[0039] Based on the scanning angle and design pattern of the target beam, calculate the amplitude weight and phase weight corresponding to each array port to form the amplitude and phase weight vector of the target beam.

[0040] The port observation results, after mutual coupling correction and feeder consistency normalization, are called and matched one-to-one with the amplitude and phase weight vectors according to the port number order to ensure the matching relationship between the observation data and the weight components.

[0041] The correction observation results of each port are multiplied by the corresponding amplitude and phase weights using complex multiplication, and the product results of all ports are vector-superimposed to form an equivalent weighted array aperture field distribution;

[0042] The array aperture field distribution is used as an equivalent input field for subsequent far-field reconstruction and beam performance index calculation. At the same time, a correspondence is established with the target beam parameters to support comparison and judgment under multi-weight conditions.

[0043] Preferably, a far-field transformation is performed on the equivalent aperture field to obtain indices such as main lobe direction, beamwidth, sidelobe level, and scanning consistency. Phase unwrapping and smoothing are then performed on the cross-frequency results, including:

[0044] a) Arrange the equivalent port surface field according to the port spatial coordinates, and calculate the far-field radiation pattern by Fourier transform or fast approximation algorithm to obtain the radiation intensity distribution in the entire space angle range;

[0045] b) Search for the maximum radiation point in the far-field radiation pattern as the main lobe direction, calculate the angle interval at -3dB in the main lobe direction as the beamwidth, and extract the difference between the maximum radiation point and the main lobe peak value in the region outside the main lobe as the sidelobe level.

[0046] c) Repeat steps a) and b) at different scanning angles and frequencies, compare the deviation of the main lobe direction from the beamwidth, and form a scanning consistency index to reflect the stability of the beam across the entire frequency band.

[0047] In the far-field results at different frequencies, phase unwrapping operation is performed on the main lobe phase curve to eliminate the 2π periodic jump, and the moving average method is used to smooth the unwrapped phase curve to enhance the continuity and comparability of the cross-frequency results.

[0048] The main lobe direction, beamwidth, sidelobe level, and scanning consistency index are stored in correspondence with the frequency point number to form a complete test result set.

[0049] Preferably, a unique traceability identifier is generated for each test, and the weights, attitude, frequency sequence, channel baseline parameters, cross-coupling correction matrix, and calculated indicators are associated and stored. Based on preset criteria, a pass / fail conclusion and anomaly location information are output, including:

[0050] After the test is completed, the input and output information of this test is extracted, and the format and units of the input and output information are standardized to form a unified context data object; the input and output information includes target weight vector, test attitude angle, frequency point sequence, channel baseline parameters, mutual coupling correction matrix and various calculated indicators;

[0051] The context data object is deterministically serialized according to a fixed field order, a digest value is calculated using a digest algorithm, and the digest value is combined with the test time and device identifier to generate a unique traceability identifier;

[0052] Using the unique traceability identifier as the primary key, a one-to-one or one-to-many mapping relationship is established between weights, attitudes, frequency sequences, channel baseline parameters, mutual coupling correction matrices and calculation indicators, forming structured association items;

[0053] Based on preset performance criteria, the calculated indicators are compared item by item. If all indicators are within the allowable range, a qualified conclusion is output. If the indicators deviate but are still within the acceptable range, a conclusion requiring attention is output. If the indicators exceed the upper or lower limit, an abnormal conclusion is output, and the corresponding port or frequency point location is marked to form abnormal location information.

[0054] A passive antenna array beamforming test system includes:

[0055] The channel baseline estimation unit is used to deploy reference calibration sources and reference receiving links in an anechoic environment, and to estimate the amplitude and phase offset of each measurement channel under a unified time reference to obtain the channel baseline parameters.

[0056] The synchronous sampling and observation recording unit is used to synchronously sample each port of the array according to the frequency jump sequence and channel switching strategy, obtain the amplitude and phase observations of multiple frequency points, and record the attitude angle, reference source status and frequency point number.

[0057] The mutual coupling correction and normalization processing unit is used to calculate the mutual coupling correction matrix and feed line amplitude consistency factor based on the reference calibration source excitation and array self-polling data, and to perform decoupling and normalization processing on the observations of each port.

[0058] The weighted projection and aperture field generation unit is used to project the amplitude and phase weights of the target beam onto the calibrated port observation without changing the physical wiring, so as to obtain the equivalent weighted array aperture field.

[0059] The far-field transformation and performance index extraction unit is used to perform far-field transformation on the equivalent aperture field to obtain the main lobe direction, beamwidth, sidelobe level and scanning consistency indexes, and to perform phase unwrapping and smoothing on the cross-frequency point results.

[0060] The traceability identifier and conclusion output unit is used to generate a unique traceability identifier for a test, establish and store the association between weights, attitude, frequency sequence, channel baseline parameters, mutual coupling correction matrix and calculation indicators, and output the qualified conclusion and anomaly location information according to preset criteria.

[0061] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0062] First, this invention effectively solves the problem of poor amplitude and phase consistency among measurement channels in traditional testing methods by establishing channel baseline parameters. In existing technologies, amplitude and phase inconsistencies in the amplifiers, feeders, and receivers of the test link directly lead to distortion in array test results, especially significant errors in the measurement of the main lobe direction and side lobe levels. This invention utilizes a reference calibration source and a unified time base to extract the amplitude offset and phase shift of each channel, thereby providing repeatable channel baseline compensation. This ensures that observations across different channels have a unified standard, improving the reliability of subsequent beamforming performance indicators.

[0063] Secondly, the frequency hopping and channel switching strategy proposed in this invention overcomes the limitations of traditional channel-by-channel, single-frequency scanning. In existing methods, conventional single-frequency or sequential scanning cannot fully cover the multi-frequency characteristics of the array, and channel acquisition efficiency is low, easily missing dynamically changing information. This invention achieves synchronous sampling of multiple frequencies and ports through frequency hopping and rapid channel switching, ensuring the acquisition of high-resolution observation data within a limited time, and enhancing the test's adaptability to broadband arrays and dynamic scanning processes.

[0064] Third, this invention introduces mutual coupling correction and normalization processing to solve the amplitude and phase distortion problem caused by electromagnetic coupling between array ports. Traditional testing often ignores the mutual coupling effect, resulting in severe distortion of the observation results of array ports under different excitation methods. This invention constructs a mutual coupling correction matrix and calculates the feed line consistency factor by referencing the calibration source and array self-polling data, thereby achieving decoupling and amplitude and phase consistency correction of port observations. This truly reflects the equivalent aperture field distribution of the array under the target beam weight, improving the consistency between test data and actual operating conditions.

[0065] Fourth, this invention solves the problem of efficiently obtaining complete beam performance indicators in existing technologies by using far-field transformation and cross-frequency phase unwrapping. Traditional methods rely on large far-field test sites and mechanical scanning, which are costly and cumbersome, making it difficult to quickly obtain full bandwidth indicators. This invention performs far-field transformation based on the corrected aperture field, directly calculating key parameters such as main lobe direction, beamwidth, and sidelobe level. At the same time, through cross-frequency phase unwrapping and smoothing, it ensures the continuity and accuracy of broadband array test results, significantly improving test efficiency.

[0066] Fifth, this invention introduces a unique traceability identifier mechanism, solving the problem of difficulty in data tracing and anomaly localization in traditional methods. In existing array testing, test conditions, weight configurations, and result data are often stored in a scattered manner, lacking consistent correlation and traceability methods. This invention generates a unique traceability identifier to uniformly correlate and store weights, attitudes, frequency sequences, channel baseline parameters, mutual coupling correction matrices, and performance indicators, enabling rapid verification of test data and anomaly tracing, providing complete data support for array design verification and quality control. Attached Figure Description

[0067] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0068] Figure 1 A flowchart of the method provided in an embodiment of the present invention;

[0069] Figure 2 This is a schematic diagram of the system structure provided in an embodiment of the present invention. Detailed Implementation

[0070] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0071] The purpose of this invention is to provide a passive antenna array beamforming test method and system. By introducing channel baseline compensation, multi-frequency point rapid sampling, mutual coupling correction and amplitude-phase consistency processing during the test process, and combining far-field transformation and cross-frequency point phase smoothing technology, while establishing a unique traceability identifier, high-precision measurement and full-process traceability management of passive antenna array beam performance are achieved, thereby effectively improving the accuracy, efficiency and reliability of the test results.

[0072] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0073] Figure 1 The method flowchart provided in the embodiments of the present invention is as follows: Figure 1 As shown, the present invention provides a passive antenna array beamforming test method, comprising:

[0074] Step 100: Deploy a reference calibration source and a reference receiving link in an anechoic environment, estimate the amplitude and phase offset of each measurement channel under a unified time reference, and obtain the channel baseline parameters;

[0075] Step 200: Based on the frequency jump sequence and channel switching strategy, synchronously sample each port of the array to obtain the amplitude and phase observations of multiple frequency points, and record the attitude angle, reference source status and frequency point number;

[0076] Step 300: Based on the reference calibration source excitation and array self-polling data, calculate the mutual coupling correction matrix and feeder amplitude-phase consistency factor, and perform decoupling and normalization processing on the observations of each port;

[0077] Step 400: Without changing the physical wiring, project the amplitude and phase weights of the target beam onto the calibrated port observation to obtain the equivalent weighted array equivalent port field.

[0078] Step 500: Perform far-field transformation on the equivalent aperture field to obtain the main lobe direction, beamwidth, sidelobe level and scanning consistency indicators, and perform phase unwrapping and smoothing on the cross-frequency point results;

[0079] Step 600: Generate a unique traceability identifier for each test, establish and store the association between weights, attitude, frequency sequence, channel baseline parameters, mutual coupling correction matrix and calculation indicators, and output the pass conclusion and anomaly location information according to the preset criteria.

[0080] Specifically, in step 100 of this embodiment, a reference calibration source is first deployed in an anechoic chamber. This source is positioned along the far-field reference direction of the array to provide stable amplitude and phase reference signals throughout the testing process. The output power and frequency of the reference calibration source remain constant within the target test frequency band to ensure that the reference signals received by different measurement channels have consistent reference characteristics, thus serving as a basis for correcting channel amplitude and phase errors. The term "reference calibration source" refers to a signal generation device specifically designed for amplitude and phase-stable radiation, serving to provide a unified reference standard for multi-channel observation. Secondly, an equivalent reference receiving link to the antenna port is introduced into each measurement channel. This link consists of a feeder of equal length and an amplifier of the same gain, ensuring physical hardware consistency across all channels and avoiding systematic errors caused by link differences. By introducing equivalent links in each channel, the channel response can be structurally balanced, thereby improving the accuracy of subsequent amplitude and phase calibration. Finally, the reception results of the reference calibration source signal in each channel are simultaneously acquired under a unified time reference. To ensure data synchronization between channels, an external clock is used to uniformly correct the sampling time, thereby eliminating timing deviations between different channels. The received results of each channel are compared with the theoretical amplitude and phase of the reference calibration source, and the amplitude gain offset and phase offset of each channel are calculated. These amplitude gain offset and phase offset are stored as channel baseline parameters for subsequent test steps. The "channel baseline parameters" refer to the channel amplitude and phase offset values ​​measured under standard calibration conditions, used to eliminate the influence of non-ideal factors on beamforming test results.

[0081] Furthermore, this embodiment first calculates the theoretical amplitude that should be received at each port based on the rated transmit power and operating frequency of the reference calibration source, as well as the geometric path length from the calibration source to the reference phase center of each port of the array, combined with the free-space loss model and the known antenna directivity factor. The theoretical phase is then obtained based on the propagation delay and the reference phase link. The free-space loss model provides a closed-form expression for path loss and phase delay in an anechoic environment, while the antenna directivity factor corrects for gain differences caused by the reference direction and the actual placement. Together, they determine the theoretical received amplitude and theoretical received phase, serving as standard quantities for subsequent comparisons. To ensure consistency, the theoretical quantities are output in fixed units and with fixed decimal precision, and the geometric parameters and frequency indexes used in the calculation are recorded.

[0082] Under a unified time reference, the raw received data from each channel is analyzed. First, the receiver readings are converted into linear amplitude using an amplitude calibration table, and then the relative phase is extracted using a common local oscillator reference. To avoid the impact of short-term jitter on the comparison results, this embodiment robustly summarizes multiple samples of the same channel at the same frequency point within a single time window (e.g., median or extreme value removal averaging) to obtain the measured amplitude and measured phase of that channel at that frequency point. If phase foldback occurs across cycles, phase unwrapping is performed first to maintain its temporal continuity within the window. Finally, a set of measured results organized according to "channel number - frequency point number - time window" is formed, which serves as the input for item-by-item comparison with theoretical quantities.

[0083] The amplitude gain bias of each channel is obtained by dividing the measured amplitude at each frequency point by the theoretical amplitude. The phase offset of the channel is obtained by subtracting the measured phase from the theoretical phase and normalizing the results according to the principal value interval or unwrapping sequence. To ensure traceability, this embodiment binds the amplitude gain bias and phase offset to the channel number, frequency point number, time window identifier, and reference version number, and writes them into the channel baseline parameter table. This parameter table is used for amplitude and phase compensation of the observation data in subsequent steps, and can be updated with each test batch to maintain comparability and verifiability.

[0084] As an example, the geometric path length measurement uncertainty is no greater than 2 mm; the single time window duration is 100 ms, and each channel per frequency point is summarized with no less than 10 samples; the theoretical and measured amplitude and phase are expressed in fixed units and retained to 4 decimal places; the repeatability of amplitude gain offset is better than ±0.3dB, and the repeatability of phase offset is better than ±2°; the number of frequency points is no less than 21 and covers the target bandwidth; the time synchronization error is no more than 10 nanoseconds; the phase unwrapping cross-cycle threshold is determined by 180° and the minimum correction is performed; the channel baseline parameter table is archived by batch number and timestamp, and the version number is managed incrementally.

[0085] In step 200 of this embodiment, a predefined frequency switching sequence is first set, which involves sequentially switching the operating frequencies of the transmitter or receiver within the test bandwidth according to a fixed or optimized step sequence. The dwell time at each frequency point is designed to cover the receiver's settling time and the sampling time required for signal averaging, thereby ensuring the amplitude and phase stability of the measurements acquired at that frequency point. The so-called "frequency switching sequence" refers to switching between frequencies point by point or across points within the bandwidth according to a pre-planned frequency point sequence, enabling the test to cover the full frequency band characteristics within a limited time.

[0086] Secondly, at each target frequency, the array ports are activated sequentially or in parallel according to the channel switching strategy. The channel switching strategy defines the polling order and parallel grouping method of each port within a single test time slot to ensure that all array ports complete response acquisition under the same frequency conditions. For large-scale arrays, grouped parallel switching is preferred to reduce test time and avoid timing inconsistencies caused by excessive hardware switching. This strategy ensures that all ports have a balanced observation opportunity within the frequency range, avoiding amplitude and phase differences between channels caused by sequence offset.

[0087] Finally, under a unified time reference, the received signal of each activated port is synchronously sampled for amplitude and phase. Sampling triggering relies on an external clock or global trigger signal for alignment, thereby ensuring strict time consistency of amplitude and phase data across channels. After sampling is completed, the observation results of that port are bound with the simultaneously recorded attitude angles, the operating status of the reference calibration source, and the frequency point number to form a complete structured observation entry. The "attitude angle" refers to the azimuth and elevation angles of the array relative to the reference coordinate system at the sampling time, used to correct for the impact of spatial position changes on the observation; the "reference source status" refers to whether the calibration source is in normal transmission, standby, or off operating mode at that frequency point. By storing observation entries, the traceability and verifiability of data in subsequent processing are ensured.

[0088] In this embodiment, when the test equipment lacks multi-channel parallel acquisition capabilities, sequential activation is preferred for channel switching. This involves activating each array port sequentially according to its port number within a frequency jump cycle. This ensures that all ports complete observations under the same frequency conditions, avoiding inconsistencies caused by frequency switching. A "frequency jump cycle" refers to the process of completing a full frequency sequence in a preset frequency jump table. Sequential activation ensures the comparability of different ports under the same signal conditions and improves the stability of channel baseline parameters. When multi-channel parallel acquisition capabilities are available, the array ports can be divided into several parallel groups, and ports within each parallel group can be sampled simultaneously at each frequency. A "parallel group" refers to a set of ports that can be activated simultaneously and remain isolated from each other in terms of hardware structure. Dividing the ports into parallel groups shortens the time for a single test and improves overall test efficiency. Depending on the test scale and equipment capabilities, sequential activation and parallel grouping can be used individually or in combination to balance channel consistency with the efficiency requirements of large-scale arrays, ensuring the integrity and repeatability of test data.

[0089] In step 300 of this embodiment, the reference calibration source is first kept in a stable radiation state with a fixed direction in an anechoic environment. Each array port is then sequentially sampled and received. Simultaneously, the excitation and observation data of the array in self-polling mode are combined to obtain the measured amplitude and phase observations for each port. "Array self-polling" refers to sequentially exciting a single port in the array while simultaneously recording the reception results of other ports; its purpose is to reveal the mutual coupling relationship between the array ports. By jointly acquiring both the reference calibration source data and the self-polling data, the channel correction information is ensured to have both an absolute amplitude and phase reference and reflects the coupling characteristics between the ports.

[0090] Next, the measured amplitude and phase observations of each port under the excitation of the reference calibration source are compared one by one with the output results of the theoretical aperture model to extract the amplitude gain factor and phase offset factor of each port. This set of factors is stored as the "feeder amplitude and phase consistency factor". The so-called "feeder amplitude and phase consistency factor" refers to the amplitude and phase correction amount introduced by hardware differences such as feeder length, amplifier gain, and RF link inconsistency. It is used to compensate for the non-ideal characteristics of different channels on the hardware path, so that the observations of each port are comparable under the same reference.

[0091] Finally, in the array's self-polling data, the amplitude and phase responses of adjacent ports when a certain port is excited are analyzed. Coupling parameters between ports are extracted and arranged in order of port number to form a mutual coupling correction matrix. This mutual coupling correction matrix is ​​used to perform matrix inversion on the measured results of each port to eliminate mutual coupling interference effects. Then, the feeder amplitude-phase consistency factor is used to normalize the decoupled results, ensuring that the amplitude and phase of all ports are expressed under a unified reference, thus ensuring that subsequent beam weighting and far-field calculations can reflect the true radiation performance of the array.

[0092] In step 500 of this embodiment, firstly, based on the scanning angle and design pattern of the target beam, the amplitude weight and phase weight corresponding to each array port are calculated using the array antenna geometry and operating frequency parameters to form the amplitude and phase weight vector of the target beam. The so-called "amplitude and phase weight vector" refers to the complex weight assigned to each array port in the beamforming design, which is used to control the contribution intensity and phase of the port in the superimposed field, thereby realizing the directionality and shape of the target beam.

[0093] Secondly, port observation data that has undergone mutual coupling correction and feeder amplitude-phase consistency processing is retrieved and matched one-to-one with the amplitude-phase weight vector according to port number order to ensure the matching relationship between observations and weight components. This is done to avoid port mismatch during weight superposition, thereby ensuring the accuracy of projection calculation. The corrected port observations have eliminated channel inconsistencies and mutual coupling effects, thus accurately reflecting the equivalent input characteristics of each port under the target beam weight.

[0094] Finally, the corrected observation results of each port are multiplied by the corresponding amplitude and phase weights using complex multiplication, and the results of all ports are vector-superimposed to form an equivalent weighted distribution on the array aperture. This distribution is the "array equivalent aperture field," which is essentially an equivalent substitute for the physical aperture field. Without changing the actual physical wiring, it achieves the target beam weighting effect through mathematical projection. The obtained array equivalent aperture field serves as the input for subsequent far-field transformation and beam performance index calculations, and a correspondence is established with the design parameters of the target beam to support comparative analysis and performance evaluation under various weighting configurations.

[0095] In step 500 of this embodiment, the equivalent aperture field data obtained from each array port are first arranged according to the geometric coordinates of the port in physical space, and the far-field radiation pattern is calculated using Fourier transform or a fast approximation algorithm to obtain the radiation intensity distribution over the entire spatial angle range. The "equivalent aperture field" refers to the aperture field distribution after mutual coupling correction, amplitude-phase consistency normalization, and beamweight projection, which is equivalent to the physical radiation state of the actual antenna array under the corresponding weight. The "far-field radiation pattern" refers to the angular radiation distribution of the antenna at a long distance obtained through mathematical transformation, used to characterize the antenna's directivity. Secondly, in the obtained far-field radiation pattern, the system automatically searches for the maximum radiation point, takes the angle corresponding to that point as the main lobe direction, and calculates the angular interval at which the intensity near the main lobe direction drops to half the peak power, as the beamwidth. Simultaneously, in the angular region outside the main lobe, the power difference between the maximum radiation point and the main lobe peak value is extracted as the sidelobe level. In this way, the directivity performance parameters of the array under the target weight can be accurately extracted.

[0096] Next, the aforementioned far-field transformation and performance extraction steps were repeated at different scanning angles and operating frequencies. The deviations in the main lobe direction and beamwidth under each frequency and scanning angle condition were compared to form a "scan consistency index." The scan consistency index is a quantitative parameter that measures the stability of the array's beam performance across frequency bands and at different scanning angles. It reflects whether the array can maintain consistent directional characteristics across the entire frequency band and wide scanning angles. Finally, in the far-field results at the cross-frequency points, phase unwrapping was performed on the main lobe phase curve to eliminate discontinuities caused by the periodic 2π phase transitions. A moving average method was then used to smooth the unwrapped phase curve to enhance the continuity and comparability of the cross-frequency point results. Finally, the main lobe direction, beamwidth, sidelobe level, and scan consistency index were stored one-to-one with the frequency point number to form a complete test result set for subsequent comparison, verification, and performance evaluation.

[0097] In step 600 of this embodiment, after a complete array beamforming test is completed, the input and output information involved in this test is first extracted, including the amplitude and phase weight vector of the target beam, the test attitude angle, the frequency sequence, the channel baseline parameters, the mutual coupling correction matrix, and various calculated indicators obtained from the far-field transformation. The above data undergoes a unified format and unit conversion to form a standardized context data object. The so-called "context data object" refers to a structured set of all input conditions and output results generated in a single test, used to ensure the consistency of subsequent data storage and traceability processes.

[0098] Subsequently, the context data object is deterministically serialized according to a fixed field order, and a unique digest value is calculated using a digest algorithm. This digest value is then combined with the test timestamp and device identifier to generate a unique traceability identifier for this test. A "unique traceability identifier" is a digital fingerprint that can uniquely correspond to the entire test process in the database, used to quickly locate and verify the authenticity and integrity of test data during subsequent queries or comparisons.

[0099] Finally, a structured mapping is established between the input and output information using a unique traceability identifier as the primary key. Specifically, weight vectors, attitude angles, frequency sequences, channel baseline parameters, mutual coupling correction matrices, and calculated indicators are all bound to this traceability identifier in a one-to-one or one-to-many manner. Simultaneously, each calculated indicator is compared item by item according to preset performance criteria. If all indicators are within the allowable range, a qualified conclusion is output; if individual indicators deviate slightly but are still within the acceptable range, a conclusion requiring attention is output; if an indicator seriously exceeds the limit, an abnormal conclusion is output, and the corresponding port number or frequency point location is marked, forming an anomaly location information. In this way, not only is the archiving and traceability of results completed, but also rapid diagnosis and pinpoint analysis of test anomalies are achieved.

[0100] Corresponding to the above methods, such as Figure 2 As shown, this embodiment also provides a passive antenna array beamforming test system, including:

[0101] The channel baseline estimation unit is used to deploy reference calibration sources and reference receiving links in an anechoic environment, and to estimate the amplitude and phase offset of each measurement channel under a unified time reference to obtain the channel baseline parameters.

[0102] The synchronous sampling and observation recording unit is used to synchronously sample each port of the array according to the frequency jump sequence and channel switching strategy, obtain the amplitude and phase observations of multiple frequency points, and record the attitude angle, reference source status and frequency point number.

[0103] The mutual coupling correction and normalization processing unit is used to calculate the mutual coupling correction matrix and feed line amplitude consistency factor based on the reference calibration source excitation and array self-polling data, and to perform decoupling and normalization processing on the observations of each port.

[0104] The weighted projection and aperture field generation unit is used to project the amplitude and phase weights of the target beam onto the calibrated port observation without changing the physical wiring, so as to obtain the equivalent weighted array aperture field.

[0105] The far-field transformation and performance index extraction unit is used to perform far-field transformation on the equivalent aperture field to obtain the main lobe direction, beamwidth, sidelobe level and scanning consistency indexes, and to perform phase unwrapping and smoothing on the cross-frequency point results.

[0106] The traceability identifier and conclusion output unit is used to generate a unique traceability identifier for a test, establish and store the association between weights, attitude, frequency sequence, channel baseline parameters, mutual coupling correction matrix and calculation indicators, and output the qualified conclusion and anomaly location information according to preset criteria.

[0107] The beneficial effects of this invention are as follows:

[0108] (1) This invention establishes channel baseline parameters in a noise-free environment and implements frequency jumps and channel synchronous sampling on a unified time reference, which significantly reduces the impact of multi-channel amplitude and phase inconsistency and sampling timing drift on the results; the observation items are simultaneously bound to attitude angle, reference source status and frequency point number, so that the data under the same frequency and attitude have comparability and verifiability, thereby improving the repeatability of the test and cross-batch consistency.

[0109] (2) This invention estimates the mutual coupling correction matrix based on the reference calibration source and array self-polling data, and extracts the feed line amplitude-phase consistency factor to perform decoupling and normalization processing on port observations. Without relying on empirical weights, it eliminates the systematic deviation caused by inter-port coupling and hardware path differences, and can truly restore the equivalent aperture response of the array under the target working state, significantly improving the accuracy of key indicators such as main lobe direction, side lobe level and beamwidth.

[0110] (3) This invention does not change the physical wiring, but directly projects the amplitude and phase weights of the target beam onto the calibrated port observation to obtain the array equivalent port field, and completes the far-field transformation and index extraction accordingly; combined with cross-frequency point phase unwrapping and smoothing, it forms a continuous evaluation capability for broadband and wide scanning angle conditions. Compared with the traditional far-field turntable or port-by-port rewiring method, the test efficiency and coverage are improved simultaneously, and it is more robust to installation errors and short-term drift.

[0111] (4) This invention generates a unique traceability identifier for each test, establishes a full-link association between weight, attitude, frequency sequence, channel baseline parameters, mutual coupling correction matrix and calculation indicators, and automatically outputs qualified conclusions and abnormal location information based on preset criteria. This mechanism realizes the consistency tracking and rapid diagnosis of results and acquisition context, which is convenient for batch release, process optimization and quality closed-loop management.

[0112] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0113] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A passive antenna array beamforming test method, characterized in that, include: A reference calibration source and a reference receiving link are deployed in an anechoic environment. The amplitude and phase offset of each measurement channel are estimated under a unified time reference to obtain the channel baseline parameters. Based on the frequency jump sequence and channel switching strategy, synchronous sampling is performed on each port of the array to obtain amplitude and phase observations of multiple frequency points, and the attitude angle, reference source status and frequency point number are recorded. Based on the reference calibration source excitation and array self-polling data, the mutual coupling correction matrix and feeder amplitude consistency factor are calculated, and the observations at each port are decoupled and normalized. Without changing the physical wiring, the amplitude and phase weights of the target beam are projected onto the calibrated port observation to obtain the equivalent weighted array equivalent port field. The equivalent aperture field is transformed into a far-field field to obtain the main lobe direction, beamwidth, sidelobe level and scanning consistency indicators, and the cross-frequency point results are unwrapped and smoothed. Generate a unique traceability identifier for each test, establish and store the association between weights, attitude, frequency sequence, channel baseline parameters, mutual coupling correction matrix and calculated indicators, and output the pass conclusion and anomaly location information according to preset criteria.

2. The passive antenna array beamforming test method according to claim 1, characterized in that, A reference calibration source and a reference receiver link are deployed in an anechoic environment. The amplitude and phase offsets of each measurement channel are estimated under a unified time reference to obtain the channel baseline parameters, including: A reference calibration source with stable amplitude and phase is placed in the far-field reference direction in the anechoic chamber, and the output power and frequency of the reference calibration source are kept constant within the target test frequency band to serve as a reference signal source for amplitude and phase. A reference receiving link equivalent to the antenna port is introduced in each measurement channel. The reference receiving link includes an equal-length feed line and an identical gain amplifier to ensure hardware consistency between different channels. The receiving results of the reference calibration source signal in each channel are acquired simultaneously under a unified time reference, and the sampling time is synchronized and corrected using an external clock to eliminate timing differences between channels. The received results of each channel are compared with the theoretical amplitude and phase of the reference calibration source. The amplitude gain bias and phase offset of each channel are calculated and stored as channel baseline parameters.

3. The passive antenna array beamforming test method according to claim 2, characterized in that, The received results of each channel are compared with the theoretical amplitude and phase of the reference calibration source. The amplitude gain bias and phase offset of each channel are calculated, and the amplitude gain bias and phase offset are stored as channel baseline parameters, including: Based on the rated transmit power and spatial geometric path length of the reference calibration source, and combined with the free space loss model, the theoretical received amplitude and theoretical received phase at the target frequency are calculated. Under a unified time reference, the reception results of each channel are analyzed to obtain the measured received amplitude and measured received phase, which are used as the measured results. The measured results are compared with the theoretical results, and the amplitude gain bias and phase offset of each channel are calculated using the following formula: Among them, G ch Let be the amplitude gain bias of the ch-th channel. A represents the measured received amplitude of the ch-th channel. theo For the theoretical received amplitude, Δφ ch Let be the phase offset of the ch-th channel. φ is the measured received phase of the ch-th channel. theo The theoretical receiving phase; The calculated amplitude gain offset and phase offset are bound according to the channel number, frequency point number and time window identifier, and written into the channel baseline parameter table.

4. The passive antenna array beamforming test method according to claim 1, characterized in that, Based on the frequency jump sequence and channel switching strategy, synchronous sampling is performed on each port of the array to obtain amplitude and phase observations at multiple frequency points, and the attitude angle, reference source state, and frequency point number are recorded, including: According to the preset frequency switching sequence, the operating frequency of the transmitter or receiver is switched sequentially, and the dwell time of each frequency point meets the stability requirements of the sampling. At each frequency point, each array port is activated sequentially or in parallel according to the channel switching strategy, so that each port can obtain amplitude and phase response under the same frequency point conditions. Under a unified time reference, the received signal of the activated port is synchronously sampled in terms of amplitude and phase. The sampling process is aligned with the external clock or trigger signal to ensure that the cross-channel results have strict time consistency. When sampling each frequency point and channel, the observation results are bound with the corresponding attitude angle, reference source operating status, and frequency point number to form a structured observation entry.

5. The passive antenna array beamforming test method according to claim 4, characterized in that, Channel switching strategies include: Within one frequency transition cycle, each array port is activated sequentially according to its port number, ensuring all ports complete observations at the same frequency; or When multi-channel parallel acquisition capability is available, the array port is divided into several parallel groups, and the parallel groups are sampled simultaneously in each frequency point to shorten the test time. The sequential activation and group parallel methods can be selected or combined according to the test scale and equipment capability to balance channel consistency and test efficiency.

6. The passive antenna array beamforming test method according to claim 1, characterized in that, Based on the reference calibration source excitation and array self-polling data, the mutual coupling correction matrix and feeder amplitude-phase consistency factor are calculated. Decoupling and normalization processing is then performed on the observations at each port, including: Under the fixed-direction excitation of the reference calibration source, each array port is sequentially sampled and the array self-polling data is acquired to obtain the measured amplitude and phase observations of each port. The measured results of each port under the excitation of the reference calibration source are compared with the output of the theoretical aperture model. The amplitude gain factor and phase offset factor of each port are extracted, and the amplitude gain factor and the phase offset factor are summarized into the feeder amplitude and phase consistency factor, which is used to characterize the differences between the feeder and hardware path between ports. In the array self-polling data, the response amplitude and phase characteristics of adjacent ports are analyzed when a certain port is excited, the coupling relationship between each port is established, and the parameters of the coupling relationship are arranged and combined to form a mutual coupling correction matrix; The measured results of each port are inverted using the mutual coupling correction matrix to eliminate the influence of mutual coupling interference. The decoupled results are then normalized according to the feeder amplitude-phase consistency factor so that the amplitude and phase of all ports are expressed under a unified reference.

7. The passive antenna array beamforming test method according to claim 1, characterized in that, Without altering the physical wiring, the amplitude and phase weights of the target beam are projected onto the calibrated port observations to obtain the equivalent weighted array equivalent port field, including: Based on the scanning angle and design pattern of the target beam, calculate the amplitude weight and phase weight corresponding to each array port to form the amplitude and phase weight vector of the target beam. The port observation results, after mutual coupling correction and feeder consistency normalization, are called and matched one-to-one with the amplitude and phase weight vectors according to the port number order to ensure the matching relationship between the observation data and the weight components. The correction observation results of each port are multiplied by the corresponding amplitude and phase weights using complex multiplication, and the product results of all ports are vector-superimposed to form an equivalent weighted array aperture field distribution; The array aperture field distribution is used as an equivalent input field for subsequent far-field reconstruction and beam performance index calculation. At the same time, a correspondence is established with the target beam parameters to support comparison and judgment under multi-weight conditions.

8. The passive antenna array beamforming test method according to claim 1, characterized in that, The equivalent aperture field is transformed in the far field to obtain indices such as main lobe direction, beamwidth, sidelobe level, and scanning consistency. Phase unwrapping and smoothing are then performed on the cross-frequency results, including: a) Arrange the equivalent port surface field according to the port spatial coordinates, and calculate the far-field radiation pattern by Fourier transform or fast approximation algorithm to obtain the radiation intensity distribution in the entire space angle range; b) Search for the maximum radiation point in the far-field radiation pattern as the main lobe direction, calculate the angle interval at -3dB in the main lobe direction as the beamwidth, and extract the difference between the maximum radiation point and the main lobe peak value in the region outside the main lobe as the sidelobe level. c) Repeat steps a) and b) at different scanning angles and frequencies, compare the deviation of the main lobe direction from the beamwidth, and form a scanning consistency index to reflect the stability of the beam across the entire frequency band. In the far-field results at different frequencies, phase unwrapping operation is performed on the main lobe phase curve to eliminate the 2π periodic jump, and the moving average method is used to smooth the unwrapped phase curve to enhance the continuity and comparability of the cross-frequency results. The main lobe direction, beamwidth, sidelobe level, and scanning consistency index are stored in correspondence with the frequency point number to form a complete test result set.

9. The passive antenna array beamforming test method according to claim 1, characterized in that, Generate a unique traceability identifier for each test, establish and store the association between weights, attitude, frequency sequence, channel baseline parameters, cross-coupling correction matrix and calculated indicators, and output a pass / fail conclusion and anomaly location information based on preset criteria, including: After the test is completed, the input and output information of this test is extracted, and the format and units of the input and output information are standardized to form a unified context data object; the input and output information includes target weight vector, test attitude angle, frequency point sequence, channel baseline parameters, mutual coupling correction matrix and various calculated indicators; The context data object is deterministically serialized according to a fixed field order, a digest value is calculated using a digest algorithm, and the digest value is combined with the test time and device identifier to generate a unique traceability identifier; Using the unique traceability identifier as the primary key, a one-to-one or one-to-many mapping relationship is established between weights, attitudes, frequency sequences, channel baseline parameters, mutual coupling correction matrices and calculation indicators, forming structured association items; Based on preset performance criteria, the calculated indicators are compared item by item. If all indicators are within the allowable range, a qualified conclusion is output. If the indicators deviate but are still within the acceptable range, a conclusion requiring attention is output. If the indicators exceed the upper or lower limit, an abnormal conclusion is output, and the corresponding port or frequency point location is marked to form abnormal location information.

10. A passive antenna array beamforming test system, characterized in that, include: The channel baseline estimation unit is used to deploy reference calibration sources and reference receiving links in an anechoic environment, and to estimate the amplitude and phase offset of each measurement channel under a unified time reference to obtain the channel baseline parameters. The synchronous sampling and observation recording unit is used to synchronously sample each port of the array according to the frequency jump sequence and channel switching strategy, obtain the amplitude and phase observations of multiple frequency points, and record the attitude angle, reference source status and frequency point number. The mutual coupling correction and normalization processing unit is used to calculate the mutual coupling correction matrix and feed line amplitude consistency factor based on the reference calibration source excitation and array self-polling data, and to perform decoupling and normalization processing on the observations of each port. The weighted projection and aperture field generation unit is used to project the amplitude and phase weights of the target beam onto the calibrated port observation without changing the physical wiring, so as to obtain the equivalent weighted array aperture field. The far-field transformation and performance index extraction unit is used to perform far-field transformation on the equivalent aperture field to obtain the main lobe direction, beamwidth, sidelobe level and scanning consistency indexes, and to perform phase unwrapping and smoothing on the cross-frequency point results. The traceability identifier and conclusion output unit is used to generate a unique traceability identifier for a test, establish and store the association between weights, attitude, frequency sequence, channel baseline parameters, mutual coupling correction matrix and calculation indicators, and output the qualified conclusion and anomaly location information according to preset criteria.

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