Active phased array radar calibration method

Abstract

The invention relates to the field of phased radars, and discloses an active phased array radar calibration method, which is used for improving the accuracy of actually measured phase data. Comprising the following steps: calculating theoretical excitation phases of radiation units according to an antenna array physical geometric structure and a target beam directional angle; enabling the antenna to sequentially excite the radiation units and collect coupling signals in a single-channel mode, and performing analysis to obtain an actually measured amplitude, a phase and a phase deviation; synthesizing the theoretical excitation phase and the phase deviation to generate an actual emission phase, and constructing a phase compensation lookup table; and after compensation by using the lookup table, measuring the actual directional diagram, and if not, performing fine adjustment. The calibration precision and reliability are improved, and the high-precision detection requirement of the active phased array radar can be met.

Description

Technical Field

[0001] This invention relates to the field of phased array radar, and more particularly to a calibration method for active phased array radar. Background Technology

[0002] Active phased array radar, with its significant advantages such as rapid beam scanning, multi-target tracking, and high-precision detection, has been widely used in many key fields such as military defense, aerospace, and meteorological monitoring. Its core principle is to achieve flexible beam pointing and shaping by precisely controlling the excitation phase of each radiating element in the antenna array, thereby meeting the detection requirements in different scenarios.

[0003] In practical applications, the performance of active phased array radars is highly dependent on the accuracy of the excitation phase of each radiating element in the antenna array. However, due to manufacturing process deviations, environmental factors, and system drift over time, there is often a deviation between the actual excitation phase of each radiating element in the antenna array and the theoretical design value. This phase deviation can lead to problems such as inaccurate radar beam pointing, increased sidelobe levels, and widened main lobe, which in turn seriously affect the radar's detection accuracy, resolution, and anti-jamming capability.

[0004] To ensure the stable and reliable operation of active phased array radar and to fully realize its performance advantages, precise calibration of the antenna array is essential to eliminate phase deviations between radiating elements. Traditional calibration methods typically employ external reference sources or far-field testing. While these methods can achieve the calibration objective to some extent, they have numerous limitations.

[0005] External reference source methods require additional complex equipment, increasing system cost and testing difficulty; Far-field testing methods have stringent requirements for the testing site and are time-consuming and labor-intensive, making it difficult to meet the needs of real-time calibration. Traditional methods often overlook the impact of system drift over time and multipath reflection interference on calibration results, making it difficult to further improve calibration accuracy.

[0006] Therefore, we propose an active phased array radar calibration method to solve the above problems. Summary of the Invention

[0007] This invention provides a calibration method for active phased array radar to improve the accuracy of measured phase data.

[0008] The first aspect of this invention provides a calibration method for an active phased array radar. The method includes: calculating the theoretical excitation phase of each radiating element based on the physical geometry of the antenna array and the target beam pointing angle; exciting each radiating element sequentially and acquiring coupled signals in single-channel operation mode, using the normal direction as a reference, and analyzing the coupled signals to obtain the measured amplitude and phase of each channel at the target point, calculating the phase deviation between the measured amplitude and phase and the theoretical value; using the theoretical excitation phase and the phase deviation, generating an actual transmission phase for each radiating element at each angle through comprehensive calculation, and constructing a phase compensation lookup table from the actual transmission phases; applying the phase compensation lookup table to compensate the antenna, measuring the measured radiation pattern, and comparing the measured radiation pattern with the ideal theoretical radiation pattern. If the angular accuracy index meets the preset error, the calibration process is considered complete; otherwise, the phase compensation lookup table is fine-tuned.

[0009] Optionally, in a first implementation of the first aspect of the present invention, the method includes: establishing a planar rectangular coordinate system for the antenna array and setting the array center as the reference origin; traversing the array structure to obtain spatial geometric coordinate data of each radiating element relative to the reference origin; analyzing the target beam pointing angle to determine the spatial propagation direction vector of the beam; using the spatial geometric coordinate data to perform projection calculation on the spatial propagation direction vector to obtain the path difference data of each radiating element relative to the reference wavefront; combining the working wavelength corresponding to the radar center frequency, converting the path difference data into an angle value proportionally to generate phase delay data; and performing phase conjugation or inversion operations on the phase delay data to calculate the theoretical excitation phase.

[0010] Optionally, in a second implementation of the first aspect of the present invention, the method includes: sending a reset command to the radar beam controller to lock the beam pointing at the zero-degree normal position and activating the electronic switch logic of polling each channel to establish a single-channel scanning configuration state; triggering a single radiating element to transmit a radio frequency signal according to the single-channel scanning configuration state, and synchronously capturing the electromagnetic wave response at each moment using a near-field or far-field probe to generate a time-coupled sampling signal; performing vector signal analysis on the time-coupled sampling signal to obtain a measured signal feature vector including real and imaginary part information; parsing the measured signal feature vector, calculating the magnitude and argument of each channel in the polar coordinate system through coordinate transformation, and determining the measured amplitude data and measured phase data; retrieving a pre-stored theoretical standard value and performing point-to-point difference operation with the measured phase data to obtain the channel phase error value.

[0011] Optionally, in a third implementation of the first aspect of the present invention, the method further includes the step of eliminating system drift error over time: selecting a fixed radiating element in the array as a reference anchor point; periodically inserting excitation commands for the reference anchor point according to a preset time step in a scanning sequence that sequentially excites all radiating elements in the array, and acquiring time-varying signals of the reference channel; extracting the phase response values ​​of the time-varying signals of the reference channel at different times, and constructing a phase drift trend curve reflecting the fluctuation of the system link over time with time as the horizontal axis; performing linear indexing or interpolation calculation on the phase drift trend curve based on the specific timestamp of the coupling signal acquired by each radiating element, and obtaining instantaneous phase drift compensation values; performing an inverse cancellation operation between the instantaneous phase drift compensation values ​​and the measured phase of the corresponding radiating element to generate drift-corrected phase data.

[0012] Optionally, in the fourth implementation of the first aspect of the present invention, the method includes: traversing a preset set of radar beam scanning angles, establishing a phase data association pair by mapping the theoretical excitation phase and the phase deviation to the physical address of the radiating element; performing an inverse compensation operation on the phase data association pair to generate an ideal calibration phase value in the continuous numerical domain; obtaining the minimum phase step accuracy of the radar phase shifter, mapping the ideal calibration phase value to a discrete hardware control level, and converting the continuous value into a digital phase control code adapted to the hardware bit width through rounding or truncation operations; and encapsulating the full array digital phase control code according to a storage protocol using the beam pointing angle as the index key to construct a phase compensation lookup table.

[0013] Optionally, in the fifth implementation of the first aspect of the present invention, the method includes: loading the phase compensation lookup table into the radar beam controller, driving the antenna array to transmit a test beam, and controlling the scanning system to record the signal strength distribution in the entire airspace to generate measured spatial radiation data; performing a peak search algorithm on the measured spatial radiation data to determine the actual spatial angle corresponding to the maximum radiation intensity, comparing the difference between the angle and the preset target beam pointing angle to generate a beam pointing deviation value; comparing the beam pointing deviation value with a preset angular accuracy tolerance threshold, and if the deviation value is less than the threshold, outputting a lock command to end the process, and if the deviation value is greater than the threshold, outputting a correction trigger command; responding to the correction trigger command, calculating linear phase slope data for correcting beam tilt based on the beam pointing deviation value, and superimposing the data into the current phase compensation lookup table to generate a corrected phase compensation lookup table.

[0014] Optionally, in the sixth implementation of the first aspect of the present invention, the method further includes: sampling the test environment using a near-field or far-field scanning system when the antenna array is not transmitting a signal in a silent state, and acquiring background noise vector data including environmental clutter and system noise floor; performing a complex-domain vector difference operation on the acquired original signal and the background noise vector data during the process of enabling the antenna to operate in single-channel mode and acquiring the coupled signal, generating a clearance response signal; and performing orthogonal demodulation analysis on the clearance response signal to separate the high-fidelity real components and imaginary components.

[0015] Optionally, in the seventh implementation of the first aspect of the present invention, the step of removing multipath reflection interference is further included: performing inverse frequency-time transformation processing on the original frequency-domain coupled signal acquired by the scanning system to map the signal from the frequency axis to the time axis, and parsing to obtain a time-domain impulse response sequence; analyzing the time-domain impulse response sequence, identifying the position of the main peak, setting a retention interval according to the width of the main peak, setting the time period outside the interval as the cutoff region, and generating a time-gated window function; performing time-domain convolution or windowing operation on the time-domain impulse response sequence with the time-domain gated window function to generate a truncated time-domain net signal; performing forward time-frequency transformation processing on the time-domain net signal to restore the signal to the frequency domain and generate a multipath suppression calibration signal.

[0016] Beneficial effects: By sequentially exciting each radiating element and acquiring the coupling signal in single-channel operating mode, and using the antenna's own signal for analysis and processing, no additional complex external reference source equipment is required, which reduces the cost and complexity of the calibration system and simplifies the calibration process; By using near-field or far-field probes to acquire coupling signals, it does not rely on strict far-field test conditions and can perform calibration tests indoors or in space-constrained environments, improving the feasibility and flexibility of calibration. By establishing a phase compensation lookup table, rapid calculation and compensation of the actual emitted phase of the radiating element at different angles is achieved. During radar operation, the lookup table can be directly invoked for phase compensation, eliminating the need for repeated complex tests and calculations, greatly improving the real-time performance of calibration and meeting the calibration requirements in dynamic scenarios. By selecting a fixed radiating element as a reference anchor point, periodically acquiring time-varying signals from the reference channel, constructing a phase drift trend curve, and performing instantaneous phase drift compensation based on the timestamps of the acquired coupled signals, the influence of system drift over time on calibration results is effectively eliminated, improving the long-term stability and performance of the radar. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of one embodiment of the active phased array radar calibration method in this invention.

[0018] Figure 2 This is a schematic diagram of one embodiment of the active phased array radar calibration device in this invention. Detailed Implementation

[0019] This invention provides an active phased array radar calibration method to improve the accuracy of measured phase data. The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" or "having" and any variations thereof are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0020] For ease of understanding, the specific process of the embodiments of the present invention is described below. Please refer to [link / reference]. Figure 1 One embodiment of the active phased array radar calibration method of the present invention includes: 101. Based on the physical geometry of the antenna array and the target beam pointing angle, calculate the theoretical excitation phase of each radiating element; It is understood that the executing entity of this invention can be an active phased array radar calibration device, a terminal, or a server; no specific limitation is made here. This embodiment of the invention will be described using a server as an example.

[0021] Specifically, a Cartesian coordinate system for the antenna array is established and the array center is set as the reference origin. The array structure is traversed to obtain the spatial geometric coordinate data of each radiating element relative to the reference origin. The target beam pointing angle is analyzed to determine the spatial propagation direction vector of the beam. The spatial geometric coordinate data is used to perform projection calculations on the spatial propagation direction vector to obtain the path difference data of each radiating element relative to the reference wavefront. By combining the working wavelength corresponding to the radar center frequency, the path difference data is converted into angle values ​​proportionally to generate phase delay data corresponding to the path difference. Perform phase conjugation or inversion operations on the phase delay data to calculate the theoretical excitation phase used to compensate for the path difference in order to form a plane wavefront.

[0022] 102. With the antenna in single-channel working mode, using the normal direction as a reference, excite each radiating element sequentially and collect the coupling signal. By analyzing the coupling signal, obtain the measured amplitude and phase of each channel at the target point, and calculate the phase deviation between the measured amplitude and phase and the theoretical value. Specifically, a reset command is sent to the radar beam controller to lock the beam pointing at the zero-degree normal position and activate the electronic switch logic that polls each channel to establish a single-channel scanning configuration state. Based on the single-channel scanning configuration, individual radiating elements are triggered to transmit radio frequency signals sequentially according to the array physical address order, and the electromagnetic wave response at each moment is synchronously captured using near-field or far-field probes to generate a time-coupled sampling signal; Vector signal analysis is performed on the time-coupled sampled signal to separate the carrier information in the time or frequency domain, extract the complex vector corresponding to each radiating element, and obtain the measured signal feature vector including the real and imaginary parts. The characteristic vector of the measured signal is analyzed, and the magnitude and argument of each channel in the polar coordinate system are calculated by coordinate transformation to determine the measured amplitude data and measured phase data. The pre-stored theoretical standard value is retrieved and compared with the measured phase data point-to-point with the actual phase data to calculate the channel phase error value used for subsequent compensation and correction.

[0023] Furthermore, the process of sequentially exciting each radiating element and acquiring the coupling signal also includes a step to eliminate the system's time-varying error: A fixed radiating element in the array is selected as a reference anchor point. In the scanning sequence that sequentially excites all the radiating elements in the array, the excitation command for the reference anchor point is periodically inserted according to the preset time step, and the time-varying signal of the reference channel throughout the entire scanning cycle is acquired. Extract the phase response values ​​of the time-varying signal of the reference channel at different times, and construct a phase drift trend curve reflecting the fluctuation of the system link over time with time as the horizontal axis; Based on the specific timestamp of the coupled signal collected by each radiating element, linear indexing or interpolation calculation is performed on the phase drift trend curve to obtain the instantaneous phase drift compensation value introduced by the system at that moment. The instantaneous phase drift compensation value is inversely canceled with the measured phase of the corresponding radiating element to generate drift-corrected phase data, which is then used to replace the original measured phase for calculating the phase deviation.

[0024] 103. Using the theoretical excitation phase and phase deviation, the actual emission phase of the radiating element at each angle is generated through comprehensive calculation, and a preliminary phase compensation lookup table is constructed from the actual emission phase. Specifically, the preset set of radar beam scanning angles is traversed, and the theoretical excitation phase and phase deviation are matched one-to-one according to the physical address of the radiation element to establish a phase data association pair including target angle, theoretical value and error value. The phase data correlation pairs are subjected to inverse compensation operation to subtract or cancel the error value from the theoretical value, and the operation results are subjected to periodic normalization to eliminate phase ambiguity and generate ideal calibration phase value in continuous numerical domain. The minimum phase step accuracy of the radar phase shifter is obtained, the ideal calibration phase value is mapped to a discrete hardware control level, and the continuous values ​​are converted into digital phase control codes adapted to the hardware bit width through rounding or truncation operations. Using the beam pointing angle as the index key, the full array digital phase control code is structurally encapsulated according to the storage protocol to construct a phase compensation lookup table that can be directly read by the radar beam controller.

[0025] 104. Apply the phase compensation lookup table to compensate the antenna. In a microwave anechoic chamber environment, obtain the measured radiation pattern through a scanning system and compare and analyze the measured radiation pattern with the ideal theoretical radiation pattern. If the angular accuracy index meets the preset error, the calibration process is considered complete; otherwise, fine-tune the phase compensation lookup table.

[0026] Specifically, the phase compensation lookup table is loaded into the radar beam controller to drive the antenna array to transmit the test beam, and the scanning system is controlled to record the signal intensity distribution in the entire airspace to generate measured spatial radiation data. A peak search algorithm is executed on the measured spatial radiation data to determine the actual spatial angle corresponding to the maximum radiation intensity. The difference between the angle and the preset target beam pointing angle is compared to generate a beam pointing deviation value. The beam pointing deviation value is compared with the preset angular accuracy tolerance threshold. If the deviation value is less than the threshold, a lock command is output to end the process. If the deviation value is greater than the threshold, a correction trigger command is output. In response to the correction trigger command, the linear phase slope data used to correct beam tilt is calculated based on the beam pointing deviation value. This data is then superimposed onto the current phase compensation lookup table to generate a corrected phase compensation lookup table, which is then used as new input feedback for the next round of verification.

[0027] 105. Noise suppression preprocessing steps performed before calculating phase deviation: In the silent state where the antenna array is not transmitting signals, the test environment is sampled using a near-field or far-field scanning system to obtain background noise vector data including environmental clutter and system noise floor. During the process of making the antenna operate in single-channel mode and acquiring coupled signals, the acquired raw signal and the background noise vector data are subjected to vector difference operation in the complex domain to generate a clearance response signal that has eliminated background interference. Orthogonal demodulation analysis is performed on the headroom response signal to separate the high-fidelity real and imaginary components, which are then used as the basic input data for calculating the measured amplitude and phase.

[0028] Specifically, before performing vector differential operations on the acquired signals to generate the clearance response signal, the process also includes a step of removing multipath reflection interference: The original frequency-domain coupled signal acquired by the scanning system is subjected to inverse frequency-time transformation processing, which maps the signal from the frequency axis to the time axis, and the time-domain impulse response sequence including the peak value of the direct wave and the tail of the reflected wave is obtained by analysis. Analyze the time-domain impulse response sequence, identify the position of the main peak, set the retention interval according to the width of the main peak, set the time period outside the interval as the cutoff region, and generate a time-gating window function for extracting the effective signal. The time-gated window function is convolved or windowed with the time-domain impulse response sequence in the time domain to force the reflected wave component in the zero cutoff region and retain the direct wave component in the retention interval to generate the truncated time-domain net signal. The truncated time-domain net signal is subjected to a forward time-frequency transformation to restore the signal to the frequency domain, generating a multipath suppression calibration signal that eliminates environmental multipath reflections. This signal is then used as input data for differential operations with the background noise vector data.

[0029] Figure 2 This is a schematic diagram of an active phased array radar calibration device provided in an embodiment of the present invention. The device 200 can vary considerably due to differences in configuration or performance. The device 200 includes a transmitter 201, a receiver 202, and a processor 203. The processor 203 can also be a controller. Figure 2 The device is referred to as "controller / processor 203". Optionally, the device 200 may also include a modem processor 205, wherein the modem processor 205 may include an encoder 206, a modulator 207, a decoder 208, and a demodulator 209.

[0030] In one example, transmitter 201 modulates (e.g., analog-to-analog conversion, filtering, amplification, and up-conversion, etc.) the output sample and generates an uplink signal, which is transmitted via an antenna to an access network device. On the downlink, the antenna receives the downlink signal transmitted by the access network device. Receiver 202 modulates (e.g., filtering, amplification, down-conversion, and digitization, etc.) the signal received from the antenna and provides an input sample. In modem processor 205, encoder 206 receives traffic data and signaling messages to be transmitted on the uplink and processes (e.g., formatting, encoding, and interleaving) the traffic data and signaling messages. Modulator 207 further processes (e.g., symbol mapping and modulation) the encoded traffic data and signaling messages and provides an output sample. Demodulator 209 processes (e.g., demodulates) the input sample and provides a symbol estimate. Decoder 208 processes (e.g., deinterleaving and decoding) the symbol estimate and provides decoded data and signaling messages to device 200. Encoder 206, modulator 207, demodulator 209, and decoder 208 can be implemented by a combined modem processor 205. These units process data according to the radio access technology used by the radio access network (e.g., LTE and other evolved systems access technologies). It should be noted that when device 200 does not include modem processor 205, the aforementioned functions of modem processor 205 can also be performed by processor 203.

[0031] The processor 203 controls and manages the operation of the device 200, and is used to execute the processing procedures performed by the device 200 in the above embodiments of this disclosure. For example, the processor 203 is also used to execute various steps of the transmitting or receiving device in the above method embodiments, and / or other steps of the technical solutions described in the embodiments of this disclosure.

[0032] Furthermore, the device 200 may also include a memory 204 for storing program code and data for the device 200.

[0033] Understandable Figure 2 Only a simplified design of device 200 is shown. In practical applications, device 200 may include any number of transmitters, receivers, processors, modem processors, memories, etc., and all devices that can implement the embodiments of this disclosure are within the protection scope of the embodiments of this disclosure.

[0034] The present invention also provides an active phased array radar calibration device, which includes a memory and a processor. The memory stores computer-readable instructions. When the computer-readable instructions are executed by the processor, the processor performs the steps of the active phased array radar calibration method in the above embodiments.

[0035] The present invention also provides a computer-readable storage medium, which can be a non-volatile computer-readable storage medium or a volatile computer-readable storage medium, wherein the computer-readable storage medium stores instructions that, when the instructions are executed on a computer, cause the computer to perform the steps of the active phased array radar calibration method.

[0036] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0037] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0038] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A calibration method for an active phased array radar, characterized in that, include: Based on the physical geometry of the antenna array and the target beam pointing angle, the theoretical excitation phase of each radiating element is calculated. In single-channel operation mode, with the normal direction as the reference, each radiating element is excited sequentially and the coupling signal is acquired. The measured amplitude and phase of each channel at the target point are obtained by analyzing the coupling signal, and the phase deviation between the measured amplitude and phase and the theoretical value is calculated. The theoretical excitation phase and the phase deviation are called, and the actual emission phase is generated for each radiating element at each angle through comprehensive calculation. The actual emission phase is used to form a phase compensation lookup table. The phase compensation lookup table is used to compensate the antenna, and the measured radiation pattern is obtained. The measured radiation pattern is then compared and analyzed with the ideal theoretical radiation pattern. If the angular accuracy index meets the preset error, the calibration process is considered complete; otherwise, the phase compensation lookup table is fine-tuned.

2. The active phased array radar calibration method according to claim 1, characterized in that, include: Establish a Cartesian coordinate system for the antenna array and set the array center as the reference origin. Traverse the array structure to obtain the spatial geometric coordinate data of each radiating element relative to the reference origin. The target beam pointing angle is analyzed to determine the spatial propagation direction vector of the beam. The spatial geometric coordinate data is then used to project the spatial propagation direction vector to obtain the path difference data of each radiating element relative to the reference wavefront. By combining the working wavelength corresponding to the radar center frequency, the path difference data is converted into angle values ​​proportionally to generate phase delay data; Perform phase conjugation or inversion operations on the phase delay data to calculate the theoretical excitation phase.

3. The active phased array radar calibration method according to claim 1, characterized in that, include: Send a reset command to the radar beam controller to lock the beam pointing at the zero-degree normal position and activate the electronic switch logic that polls each channel to establish a single-channel scanning configuration state. Based on the single-channel scanning configuration, a single radiating element is triggered to emit radio frequency signals, and the electromagnetic wave response at each moment is synchronously captured using a near-field or far-field probe to generate a time-coupled sampling signal; Vector signal analysis is performed on the time-coupled sampling signal to obtain a measured signal feature vector including real and imaginary part information; The measured signal feature vector is analyzed, and the magnitude and argument of each channel in the polar coordinate system are calculated by coordinate transformation to determine the measured amplitude data and measured phase data. The pre-stored theoretical standard value is retrieved and compared with the measured phase data point-to-point with it to obtain the channel phase error value.

4. The active phased array radar calibration method according to claim 3, characterized in that, It also includes steps to eliminate system drift errors over time: A fixed radiating element in the array is selected as a reference anchor point. In the scanning sequence that sequentially excites all the radiating elements in the array, the excitation command for the reference anchor point is periodically inserted according to the preset time step to acquire the time-varying signal of the reference channel. The phase response values ​​of the time-varying signal of the reference channel at different times are extracted, and a phase drift trend curve reflecting the fluctuation of the system link over time is constructed with time as the horizontal axis. Based on the specific timestamp of the coupling signal collected by each radiating element, linear indexing or interpolation calculation is performed on the phase drift trend curve to obtain the instantaneous phase drift compensation value; The instantaneous phase drift compensation value is then inversely canceled out with the measured phase of the corresponding radiating element to generate drift-corrected phase data.

5. The active phased array radar calibration method according to claim 3, characterized in that, include: Traverse the preset set of radar beam scanning angles, and establish a one-to-one correspondence between the theoretical excitation phase and the phase deviation according to the physical address of the radiating element to form a phase data association pair; Perform inverse compensation operation on the phase data association pair to generate an ideal calibrated phase value in the continuous numerical domain; The minimum phase step accuracy of the radar phase shifter is obtained, the ideal calibration phase value is mapped to a discrete hardware control level, and the continuous values ​​are converted into digital phase control codes adapted to the hardware bit width through rounding or truncation operations. Using the beam pointing angle as the index key, the full array digital phase control code is encapsulated according to the storage protocol to construct a phase compensation lookup table.

6. The active phased array radar calibration method according to claim 5, characterized in that, include: The phase compensation lookup table is loaded into the radar beam controller, which drives the antenna array to transmit the test beam and controls the scanning system to record the signal intensity distribution in the entire airspace, generating measured spatial radiation data. The measured spatial radiation data are subjected to a peak search algorithm to determine the actual spatial angle corresponding to the maximum radiation intensity. The angle is then compared with the preset target beam pointing angle to generate a beam pointing deviation value. The beam pointing deviation value is compared with a preset angular accuracy tolerance threshold. If the deviation value is less than the threshold, a lock command is output to end the process. If the deviation value is greater than the threshold, a correction trigger command is output. In response to the correction trigger command, linear phase slope data for correcting beam tilt is calculated based on the beam pointing deviation value, and this data is superimposed on the current phase compensation lookup table to generate a corrected phase compensation lookup table.

7. The active phased array radar calibration method according to claim 1, characterized in that, Also includes: In the silent state where the antenna array is not transmitting signals, the test environment is sampled using a near-field or far-field scanning system to obtain background noise vector data including environmental clutter and system noise floor. During the process of enabling the antenna to operate in single-channel mode and acquiring coupled signals, the acquired raw signal and the background noise vector data are subjected to a vector difference operation in the complex domain to generate a clearance response signal. The clearance response signal is subjected to orthogonal demodulation analysis to separate the high-fidelity real and imaginary components.

8. The active phased array radar calibration method according to claim 7, characterized in that, It also includes steps to remove multipath reflection interference: The original frequency-domain coupled signal acquired by the scanning system is subjected to inverse frequency-time transformation processing to map the signal from the frequency axis to the time axis, and the time-domain impulse response sequence is obtained by analysis. Analyze the time-domain impulse response sequence, identify the position of the main peak, set a retention interval based on the width of the main peak, set the time period outside the interval as the cutoff region, and generate a time-gated window function; The time-gated window function is convolved or windowed with the time-domain impulse response sequence in the time domain to generate the truncated net time-domain signal. A forward time-frequency transformation is performed on the net time-domain signal to restore the signal to the frequency domain and generate a multipath suppression calibration signal.

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