Secondary radar system calibration method for antenna coupled digital phased array systems

Abstract

The application discloses a secondary radar system calibration method of an antenna coupling prior digital phased array system, which comprises the following steps: acquiring a calibration coupling parameter set between an antenna unit in a phased array antenna of the secondary radar system and a calibration channel; constructing a theoretical target amplitude phase control parameter set; performing transmission calibration by the secondary radar system to acquire a waveform, a frequency point, a channel transmission amplitude and a phase actual control parameter set; and performing receiving calibration by the secondary radar system to acquire a waveform, a frequency point, a channel receiving amplitude and a phase actual control parameter set. The secondary radar system can automatically complete the calibration work of the transmission signal and the receiving signal, effectively improves the amplitude and phase control precision of the digital phased array system secondary radar system, thereby improving the system beam pointing precision and the main lobe level, improving the angle measurement precision and reducing the side lobe level, and enabling the secondary radar system to achieve the optimal working performance.

Description

Technical Field

[0001] This invention relates to the field of secondary radar system technology, and in particular to a calibration method for a secondary radar system based on a digital phased array with antenna coupling prior. Background Technology

[0002] Digital phased array systems offer advantages such as flexible beamforming and pointing, and high directional gain, and are widely used in secondary radar systems. However, digital phased array systems are affected by various factors, including hardware circuitry, temperature drift during operation, and chromatic dispersion at wide operating frequencies. This leads to significant errors in the amplitude and phase of the transmitted and received signals arriving at each element of the phased array antenna, compared to the actual controlled amplitude and phase. This results in problems such as inaccurate pointing and high sidelobe levels, impacting the overall system performance. By adding calibration channels to transmit and receive calibration signals, and using calibration methods to collect and process the amplitude and phase of the transmitted and received signals at each antenna element, the transmission and received signals can be corrected for normal system operation, enabling the digital phased array system to achieve optimal performance.

[0003] Traditional calibration methods involve manually measuring the antenna coupling data of a secondary radar system using a vector network analyzer, then loading prior coupling data into the system. Upon system startup, amplitude and phase data are acquired for all operating frequencies, and the actual measured amplitude and phase data are reconstructed using the prior coupling data to eliminate the influence of antenna coupling. The amplitude and phase difference value of each element is then calculated, and attenuators and phase shifters are controlled to compensate for each transceiver channel of the phased array, ensuring that the signal amplitude and phase arriving at the antenna element from each channel remain consistent. First, manual measurement of antenna coupling data using a vector network analyzer cannot simulate the actual antenna load operation of the system due to the load matching of each channel. Furthermore, time-division multiplexing of channel coupling measurements cannot eliminate the transmission effects between channels, resulting in poor measurement accuracy. Measurement errors introduced into the calibration process lead to low accuracy in system transmit and receive waveform control. Second, during system operation, the attenuation phase shifters of each channel need to be readjusted according to the amplitude and phase control requirements for beamforming. This requires two amplitude and phase control operations. Moreover, the nonlinear characteristics of the power amplification devices make it difficult to accurately control amplitude and phase accuracy during transmit calibration, often resulting in low beamforming accuracy. Third, when the system experiences operating temperature drift, the long calibration time affects normal operation. Manual measurement of the impact of temperature drift on amplitude and phase is typically used, with amplitude and phase compensation applied in different operating temperature zones for control. Traditional methods of secondary amplitude and phase control during beamforming and temperature zone compensation cannot accurately control the final amplitude and phase accuracy of the system, resulting in a significant gap between the system's ideal performance and its actual operation. Summary of the Invention

[0004] In view of this, the present invention provides a secondary radar system calibration method based on a digital phased array system with antenna coupling prior.

[0005] This invention discloses a secondary radar system calibration method based on a digital phased array system with antenna coupling prior, comprising: Step 1: Obtain the calibration coupling parameter set between the antenna elements and the calibration channel in the phased array antenna of the secondary radar system; Step 2: Obtain the amplitude and phase control parameter set of all working beams of the system antenna, and combine it with the calibration coupling parameter set to construct the theoretical target amplitude and phase control parameter set; Step 3: The secondary radar system performs transmission calibration, and based on the antenna transmission target amplitude and phase control parameter set, obtains the actual control parameter set of waveform, frequency point, and channel transmission amplitude and phase; Step 4: The secondary radar system performs reception calibration, and based on the antenna receiving target amplitude and phase control parameter set, obtains the waveform, frequency point, and channel received amplitude and phase actual control parameter set.

[0006] Further, step 1 includes: Step 101: Replace the secondary radar system antenna with an equal amplitude and phase power divider to control the secondary radar system to complete the transmission and reception of calibration signals, and collect amplitude and phase data of each operating frequency and each channel link of the secondary radar system through the calibration channel and the reception channel. ; Step 102: Using the actual secondary radar system antenna, control the secondary radar system to complete the transmission and reception of calibration signals, and collect amplitude and phase data sets for each operating frequency and each channel link of the secondary radar system through the calibration channel and the reception channel. ; Step 103: Transfer the amplitude and phase dataset from Step 101. Compared with the amplitude and phase dataset in step 102 The difference is calculated to obtain the original dataset of calibration coupling parameters; Step 104: Calculate the difference parameters of the channel links based on the operating frequency, and normalize the amplitude and phase data of all channel links using the amplitude and phase data of any channel link to form a calibration coupling parameter set.

[0007] Further, step 101 includes: Connect each TR channel in the digital front-end of the secondary radar system to the corresponding power divider port of the equal-amplitude, equal-phase power divider using equal-amplitude, equal-phase RF cables. Connect the power combiner port of the equal-amplitude, equal-phase power divider to the calibration channel in the digital front-end of the secondary radar system to simulate the actual working conditions of the antenna load of the secondary radar system. Control the secondary radar system to use normal waveforms, sequentially turn on the TR channel of the digital front-end of the secondary radar system to transmit signals, and collect the amplitude and phase data of each operating frequency point and each TR channel transmit link of the secondary radar system through the calibration channel. Then turn on the calibration channel of the secondary radar system to transmit signals, and collect the amplitude and phase data of each operating frequency point and each TR channel receive link of the secondary radar system through the TR channel of the digital front-end of the secondary radar system. Obtain the amplitude and phase dataset of all transmit and receive links. ; This refers to the amplitude data transmitted and received by the k-th TR channel at the j-th operating frequency. This refers to the phase data of the k-th TR transmit and receive channel at the j-th operating frequency. , , Indicates the total number of frequency points. This indicates the maximum number of TR channels in the digital front-end of the secondary radar system.

[0008] Further, step 102 includes: The secondary radar system operates according to the actual antenna connection method. It is controlled to use a normal beam, and the TR channel of the digital front-end of the secondary radar system is sequentially activated to transmit signals. Amplitude and phase data of each operating frequency and each TR channel transmit link of the secondary radar system are acquired through the calibration channel. Then, the calibration channel of the secondary radar system is activated to transmit signals, and amplitude and phase data of each operating frequency and each TR channel receive link of the secondary radar system are acquired through the TR channel of the digital front-end. This yields the amplitude and phase datasets of all transmit and receive links. ; For the amplitude data of the k-th TR channel at the j-th operating frequency, This refers to the phase data of the k-th TR channel at the j-th operating frequency.

[0009] Furthermore, the original data for the calibration coupling parameters are:

[0010] in, The original data for calibrating coupling parameters; The set of calibration coupling parameters is as follows:

[0011] in, For the digital front end of the secondary radar system Calibration coupling amplitude and phase data for each TR channel. , L This represents the maximum number of TR channels in the digital front-end of the secondary radar system.

[0012] Further, step 2 includes: Step 201: Obtain the theoretical control parameter set of amplitude and phase for all working beams of the system antenna. ;in, This refers to the amplitude data transmitted and received by the k-th TR channel at the j-th operating frequency corresponding to the i-th operating beam. The phase data transmitted and received by the k-th TR channel at the j-th operating frequency point corresponding to the i-th operating beam; Step 202: Use the amplitude and phase control parameter set of all working beams of the phased array antenna of the secondary radar system to perform a summation operation with the calibration coupling parameter set from Step 1 to obtain the theoretical target amplitude and phase control parameter set. .

[0013] Further, step 3 includes: Step 301: Initialize the actual control parameter set for the target amplitude and phase of the waveform, frequency point, and channel, and initialize it to 0 values. The actual control parameter set for the transmit amplitude and phase is as follows: ; Step 302: Use the actual control parameter set for amplitude and phase Control the secondary radar system to operate in the first stage The waveform, the first The operating frequency point, the first Each channel transmits a signal, and the amplitude and phase data of the current waveform are acquired through the calibration channel. ; Step 303: Use the target amplitude and phase theory target control parameter set , No. Waveform, number Operating frequency and the Subtracting the amplitude and phase data acquired in step 302 from the channel transmission amplitude and phase data yields the transmission amplitude and phase compensation parameters. And using transmission amplitude and phase compensation parameters Update the actual control parameter set for transmission amplitude and phase ; Step 304: Repeat steps 302 and 303 to complete the transmit amplitude and phase compensation parameters corresponding to all waveforms, operating frequencies, and TR channels, and update them. ; Step 305: Use the actual control parameter set for transmission amplitude and phase obtained in step 304. Complete the amplitude and phase control of the digital phased array transmission; Step 306: Repeat steps 302 to 305 until all transmit amplitude and phase compensation parameters are obtained. All amplitude parameters are less than And the phase parameters are all less than until; This is a preset value for amplitude control accuracy. This is the preset value for phase control accuracy.

[0014] Further, step 4 includes: Step 401: Initialize the actual control parameter set for waveform, frequency point, and channel receiving amplitude and phase, initially set to 0. ; Step 402: Use the received amplitude and phase control actual parameter set Control the secondary radar system to operate in the first stage The waveform, the first It operates at a specific frequency and transmits signals through the calibration channel, while the TR channel acquires current amplitude and phase data. ; Step 403: Use the amplitude and phase theory target control parameter set , No. Waveform, number Subtracting the amplitude and phase data acquired in step 402 from the received amplitude and phase data of all channels at the operating frequency point yields the received amplitude and phase compensation parameters. and use compensation parameters Update target parameter set ; Step 404: Repeat steps 402 and 403 to calculate the set of received amplitude and phase control parameters for all waveforms, operating frequencies, and the TR channel. ; Obtain the complete waveform, operating frequency, amplitude, and phase control parameter set of the TR channel. .

[0015] Furthermore, after step 4, the method further includes: When the secondary radar system is working, it dynamically updates the current working waveform, frequency point, and the actual control parameter set of amplitude and phase for transmission and reception of the channel.

[0016] Furthermore, when the secondary radar system is operating, it dynamically updates the current operating waveform, frequency point, and the actual control parameter set for the amplitude and phase of the transmission and reception of the channel, including: The secondary radar system based on the current waveform and frequency Using the actual control parameter set of amplitude and phase Control the phased array antenna to transmit and receive signals, and complete the current waveform according to steps 302, 303, 402, and 403. Operating frequency Full-channel transmit and receive amplitude and phase compensation parameters calculate; Use the obtained Update current waveform Frequency Index amplitude and phase, control the target parameter set for amplitude and phase. Waveform transmission and reception control is performed using the updated set of amplitude and phase target parameters.

[0017] Because of the adoption of the above technical solution, the present invention has the following advantages: 1. This invention can accurately measure the coupling data under high-precision antenna load conditions, eliminating the impact of errors from manual coupling data measurement using vector networks on system calibration. Based on the amplitude and phase control accuracy of the digital phased array, a parameter convergence mechanism is adopted to achieve feedback-based transmission self-calibration, solving the problem of low transmission calibration accuracy caused by the nonlinear characteristics of the power amplifier. Upon system startup, based on the phased array beam amplitude and phase weighting characteristics, waveform-level calibration is directly completed for all operating frequencies and waveform weighted amplitude and phase characteristics, forming a set of waveform amplitude and phase control parameters directly used during operation, eliminating control errors introduced by secondary amplitude and phase adjustment of the system's operating beam control. During system operation, based on the waveform amplitude and phase control target parameter set, a single calibration is rapidly superimposed according to the waveform at the current operating frequency, eliminating the influence of temperature drift. This method can significantly improve the performance of the digital phased array secondary radar system. 2. This invention provides a method for accurately measuring prior data of antenna coupling, eliminating the influence of antenna coupling measurement errors on system calibration. This calibration method uses a parameter convergence mechanism to enable a secondary radar system of digital phased array to automatically complete the calibration of transmitted and received signals, effectively improving the accuracy of phased array amplitude and phase control, adapting to different operating temperature changes, thereby improving system performance such as beam pointing accuracy, increasing main lobe level, reducing sidelobe level, and angle measurement accuracy. 3. This invention can solve the problem of low calibration accuracy caused by errors introduced by manually measuring antenna coupling using a vector network analyzer in secondary radar systems, which cannot realistically simulate the actual load operation of the system's connected antennas. 4. This invention can solve the problem of low transmission calibration accuracy caused by the nonlinear characteristics of the power amplifier in secondary radar systems, and can effectively improve the accuracy of the system's transmission amplitude and phase control. 5. This invention directly anchors all waveform control amplitude and phase parameters for calibration, forming a set of waveform amplitude and phase control target parameters used by the system. This avoids the errors introduced by the traditional method of first calibrating the system amplitude and phase consistency and then adjusting the amplitude and phase secondary control according to waveform requirements, and can effectively improve the amplitude and phase control accuracy of phased array beamforming. 6. This invention effectively solves the performance impact of system operating temperature drift by adjusting the target parameter set for waveform amplitude and phase control used in system operation, calibrating the current operating frequency and waveform during operation, and correcting the target parameter set for waveform amplitude and phase control in real time, thereby effectively improving the performance of the digital phased array system. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in the embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a block diagram of the actual working operation of the antenna load in a typical digital phased array secondary radar system in the prior art. Figure 2 This is a block diagram of the actual operation of the digital phased array secondary radar system and the power divider analog antenna load in an embodiment of the present invention. Figure 3 A schematic diagram of the waveform at 20 degrees and the radiation pattern at 1 GHz for a traditional calibration method for an 8-unit system. Figure 4 This is a schematic diagram of the 20-degree waveform and 1GHz frequency radiation pattern effect of the calibration method of the present invention for an 8-unit system. Detailed Implementation

[0020] The present invention will be further described in conjunction with the accompanying drawings and embodiments. The described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art should fall within the protection scope of the present invention.

[0021] Figure 1This is a typical block diagram of a digital phased array secondary radar system. The system consists of a signal processing unit, an RF front-end, and a phased array antenna. During transmit calibration, the signal processing unit generates a baseband signal, which is transmitted to the phased array radiating element via the RF front-end's TR channel. The signal passes through the spatial coupling element within the antenna, is acquired by the RF front-end calibration channel, and then processed by the signal processing unit. During receive calibration, the signal processing unit generates a baseband signal, which is transmitted to the phased array coupling element via the RF front-end calibration channel. The signal passes through the radiating element within the antenna, is acquired by the RF front-end's TR channel, and then processed by the signal processing unit. In actual operation, the calibrated amplitude and phase control parameters are used to control the antenna's transmit and receive beamforming, thereby realizing the secondary radar function.

[0022] Figure 2 The equal-amplitude and equal-phase power divider's power combining port is connected to the calibration channel in the digital front-end of the secondary radar system, and the equal-amplitude and equal-phase power divider's power splitting port is connected to the TR channel in the digital front-end of the secondary radar system to simulate the actual operating conditions of the secondary radar system's antenna load. In this state, the amplitude and phase data of the system's transmit and receive links are collected as a reference, which can be used to accurately calculate the calibration coupling parameters under the actual operating conditions of the secondary radar system's loaded antenna.

[0023] See Figure 2 This invention provides an embodiment of a secondary radar system calibration method based on a digital phased array system with antenna coupling prior, which includes the following steps: S1: Obtain the prior parameter set for the coupling between the antenna element and the calibration channel. ,in , , Indicates the total number of frequency points. This indicates the maximum number of TR channels in the digital front-end of the secondary radar system.

[0024] S101: Connect the secondary radar system using equal-amplitude and equal-phase RF cables and equal-amplitude and equal-phase power dividers as shown in the attached document. Figure 2 As shown, this system can accurately simulate the actual working conditions of the antenna load. The control system uses a normal beam to sequentially activate the TR channel to transmit signals, and collects amplitude and phase data of each operating frequency and each TR channel transmission link through the calibration channel; then, it transmits signals through the calibration channel and collects amplitude and phase data of each operating frequency and all channel receiving links through the TR channel; finally, it obtains a set of transmit and receive amplitude and phase data. ; This refers to the amplitude data transmitted and received by the k-th TR channel at the j-th operating frequency. This refers to the phase data of the k-th TR transmit and receive channel at the j-th operating frequency.

[0025] S102: The secondary radar system operates according to the actual antenna connection method. The system uses a normal beam to sequentially activate the TR channel for signal transmission and acquire amplitude and phase data for each operating frequency and each TR channel transmission link via the calibration channel. Then, the calibration channel is activated for signal transmission, and amplitude and phase data for each operating frequency and all channel reception links are acquired via the TR channel. Finally, a combined set of transmit and receive amplitude and phase data is obtained. ; For the amplitude data of the k-th TR channel at the j-th operating frequency, This refers to the phase data of the k-th TR channel at the j-th operating frequency.

[0026] S103: Use the amplitude and phase data from S101 Amplitude and phase data in S102 The original data of calibration coupling parameters are obtained by performing difference operations on the frequency point and TR channel. ,

[0027] S104: Based on the operating frequency, calculate the difference parameters of the TR channel links, and normalize the amplitude and phase data of all TR channel links using the amplitude and phase data of any channel link to form a calibration coupling parameter set. ,

[0028] in, For the digital front end of the secondary radar system Calibration coupling amplitude and phase data of the TR channel. , L This represents the maximum number of TR channels in the digital front-end of the secondary radar system.

[0029] S2: Construct the target amplitude and phase theoretical target control parameter set ,in , , , Indicates the total number of waveforms. Indicates the total number of frequency points. Indicates the total number of channels.

[0030] S201: Obtain the theoretical control parameter set of amplitude and phase for all working beams of the system antenna. Generally, it is obtained through antenna simulation and is determined by the antenna's number of elements, element spacing, operating frequency, beam pointing, and beamwidth (this method only requires the use of amplitude and phase control parameters, which are calculated using general theoretical calculation methods; the amplitude parameter is calculated based on the Taylor series formula, and the phase parameter is calculated based on the antenna pattern formula, which will not be elaborated in this invention).

[0031] S202: Using the set of amplitude and phase control parameters of all operating beams of the system antenna and the set of calibration coupling parameters calculated by S1. By performing summation and calculation, the final set of theoretical target control parameters for calibration amplitude and phase is obtained. :

[0032] S3: Transmission amplitude and phase calibration, acquisition of waveform, frequency point, and channel transmission amplitude and phase control target parameter set. ,in , , , Indicates the total number of waveforms. Indicates the total number of frequency points. Indicates the total number of channels.

[0033] S301: Initializes the actual control parameter set for waveform, frequency, and channel transmit amplitude and phase, initially set to 0. ; S302: Using the actual control parameter set for transmit amplitude and phase The control system operates in the first stage. Waveform, number Operating frequency, number The channel transmits signals and acquires current amplitude and phase data through the calibration channel. ; S303: Target control parameter set using target amplitude and phase theory , No. Waveform, number Operating frequency and the The transmit amplitude and phase compensation parameters are obtained by subtracting the amplitude and phase data collected by S302 from the channel transmit amplitude and phase data. And using transmission amplitude and phase compensation parameters Update the launch amplitude and phase control target parameter set ; S304: Repeat S302 and S303 to complete the calculation and update of the target amplitude and phase control parameter set for all waveforms, operating frequencies, and TR channels. ; S305: Set of actual control parameters for transmit amplitude and phase obtained using S304 And use the updated set of control parameters to complete the transmission amplitude and phase control of the digital phased array; S306: Repeat S302 to S305, up to the set of amplitude and phase compensation parameters in S303. All amplitude parameters are less than And the phase parameters are all less than Under normal circumstances Choose 3 or 6 times the system amplitude control accuracy. Choose 3 or 6 times the system phase control accuracy.

[0034] S4: Receive amplitude and phase calibration, obtain waveform, frequency point, and channel received amplitude and phase actual control parameter set. ,in , , , Indicates the total number of waveforms. Indicates the total number of frequency points. Indicates the total number of channels.

[0035] S401: Initialize the actual control parameter set for waveform, frequency, and channel amplitude and phase reception, initially set to 0. ; S402: Use the actual control parameter set for received amplitude and phase The control system operates in the first stage. Waveform, number The operating frequency is set, and signals are transmitted through the calibration channel, while the TR channel acquires the current amplitude and phase data. ; S403: Target control parameter set using amplitude and phase theory , No. Waveform, number The received amplitude and phase compensation parameters are obtained by subtracting the amplitude and phase data collected by S402 from the received amplitude and phase data of all channels at the operating frequency and all channels. and use compensation parameters Update target parameter set ,

[0036] S404: Repeat S402 and S403 to complete the set of receive amplitude and phase control parameters for all waveforms, operating frequencies, and TR channels. Calculate; obtain the complete waveform, operating frequency, TR channel amplitude, and actual control parameter set. .

[0037] S5: Updates the actual control parameter set for amplitude and phase during system operation. .

[0038] S501: The system, based on the working period and the current waveform... and frequency Select and use the actual control parameter set. Control the phased array antenna to transmit and receive signals, and complete the current waveform according to S302, S303, S402, and S403. Operating frequency Full-channel transmit and receive amplitude and phase compensation parameters calculate; S502: Obtained using S501 Update current waveform Frequency Index amplitude phase control target parameters The updated amplitude and phase parameters are used for waveform transmission and reception control.

[0039] Figure 3 A schematic diagram of the radiation pattern effect at 1GHz frequency and 20-degree waveform for a traditional calibration method for an 8-element system (8 antenna elements, 8 TR channels of a secondary radar system); Figure 4 This is a schematic diagram of the calibration method of the present invention for an 8-element system (a secondary radar system with 8 antenna elements and 8 TR channels), showing the waveform at 20 degrees and the radiation pattern at 1 GHz frequency.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A secondary radar system calibration method based on a digital phased array system with antenna coupling prior, characterized in that, include: Step 1: Obtain the calibration coupling parameter set between the antenna elements and the calibration channel in the phased array antenna of the secondary radar system; Step 2: Obtain the amplitude and phase control parameter set of all working beams of the system antenna, and combine it with the calibration coupling parameter set to construct the theoretical target amplitude and phase control parameter set; Step 3: The secondary radar system performs transmission calibration, and based on the antenna transmission target amplitude and phase control parameter set, obtains the actual control parameter set of waveform, frequency point, and channel transmission amplitude and phase; Step 4: The secondary radar system performs reception calibration, and based on the antenna receiving target amplitude and phase control parameter set, obtains the waveform, frequency point, and channel received amplitude and phase actual control parameter set; Step 1 includes: Step 101: Replace the secondary radar system antenna with an equal amplitude and phase power divider to control the secondary radar system to complete the transmission and reception of calibration signals, and collect amplitude and phase data of each operating frequency and each channel link of the secondary radar system through the calibration channel and the reception channel. ; Step 102: Using the actual secondary radar system antenna, control the secondary radar system to complete the transmission and reception of calibration signals, and collect amplitude and phase data sets for each operating frequency and each channel link of the secondary radar system through the calibration channel and the reception channel. ; Step 103: Transfer the amplitude and phase dataset from Step 101. Compared with the amplitude and phase dataset in step 102 By subtracting the values, we obtain the original dataset of calibration coupling parameters; Step 104: Calculate the difference parameters of the channel links based on the operating frequency, and normalize the amplitude and phase data of all channel links using the amplitude and phase data of any channel link to form a calibration coupling parameter set; Step 2 includes: Step 201: Obtain the theoretical control parameter set of amplitude and phase for all working beams of the system antenna. ;in, This refers to the amplitude data transmitted and received by the k-th TR channel at the j-th operating frequency corresponding to the i-th operating beam. The phase data transmitted and received by the k-th TR channel at the j-th operating frequency point corresponding to the i-th operating beam; Step 202: Use the amplitude and phase control parameter set of all working beams of the phased array antenna of the secondary radar system to perform a summation operation with the calibration coupling parameter set from Step 1 to obtain the theoretical target amplitude and phase control parameter set. .

2. The secondary radar system calibration method for a digital phased array system with antenna coupling prior as described in claim 1, characterized in that, Step 101 includes: Connect each TR channel in the digital front-end of the secondary radar system to the corresponding power divider port of the equal-amplitude, equal-phase power divider using equal-amplitude, equal-phase RF cables. Connect the power combiner port of the equal-amplitude, equal-phase power divider to the calibration channel in the digital front-end of the secondary radar system to simulate the actual working conditions of the antenna load of the secondary radar system. Control the secondary radar system to use normal waveforms, sequentially turn on the TR channel of the digital front-end of the secondary radar system to transmit signals, and collect the amplitude and phase data of each operating frequency point and each TR channel transmit link of the secondary radar system through the calibration channel. Then turn on the calibration channel of the secondary radar system to transmit signals, and collect the amplitude and phase data of each operating frequency point and each TR channel receive link of the secondary radar system through the TR channel of the digital front-end of the secondary radar system. Obtain the amplitude and phase dataset of all transmit and receive links. ; This refers to the amplitude data transmitted and received by the k-th TR channel at the j-th operating frequency. This refers to the phase data of the k-th TR transmit and receive channel at the j-th operating frequency. , , Indicates the total number of frequency points. This indicates the maximum number of TR channels in the digital front-end of the secondary radar system.

3. The secondary radar system calibration method based on a digital phased array system with antenna coupling prior as described in claim 2, characterized in that, Step 102 includes: The secondary radar system operates according to the actual antenna connection method. It is controlled to use a normal beam, and the TR channel of the digital front-end of the secondary radar system is sequentially activated to transmit signals. Amplitude and phase data of each operating frequency and each TR channel transmit link of the secondary radar system are acquired through the calibration channel. Then, the calibration channel of the secondary radar system is activated to transmit signals, and amplitude and phase data of each operating frequency and each TR channel receive link of the secondary radar system are acquired through the TR channel of the digital front-end. This yields the amplitude and phase datasets of all transmit and receive links. ; For the amplitude data of the k-th TR channel at the j-th operating frequency, This refers to the phase data of the k-th TR channel at the j-th operating frequency.

4. The secondary radar system calibration method for a digital phased array system with antenna coupling prior as described in claim 3, characterized in that, The original data for the calibration coupling parameters are: in, The original data for calibrating coupling parameters; The set of calibration coupling parameters is as follows: in, For the digital front end of the secondary radar system Calibration coupling amplitude and phase data for each TR channel. , L This represents the maximum number of TR channels in the digital front-end of the secondary radar system.

5. The secondary radar system calibration method for a digital phased array system with antenna coupling prior as described in claim 1, characterized in that, Step 3 includes: Step 301: Initialize the actual control parameter set for the target amplitude and phase of the waveform, frequency point, and channel, and initialize it to 0 values. The actual control parameter set for the transmit amplitude and phase is as follows: ; Step 302: Use the actual control parameter set for amplitude and phase Control the secondary radar system to operate in the first stage The waveform, the first The operating frequency point, the first Each channel transmits a signal, and the amplitude and phase data of the current waveform are acquired through the calibration channel. ; Step 303: Use the target amplitude and phase theory target control parameter set , No. Waveform, number Operating frequency and the Subtracting the amplitude and phase data acquired in step 302 from the channel transmission amplitude and phase data yields the transmission amplitude and phase compensation parameters. And using transmission amplitude and phase compensation parameters Update the actual control parameter set for transmission amplitude and phase ; Step 304: Repeat steps 302 and 303 to complete the transmit amplitude and phase compensation parameters corresponding to all waveforms, operating frequencies, and TR channels, and update them. ; Step 305: Use the actual control parameter set for transmission amplitude and phase obtained in step 304. Complete the amplitude and phase control of the digital phased array transmission; Step 306: Repeat steps 302 to 305 until all transmit amplitude and phase compensation parameters are obtained. All amplitude parameters are less than And the phase parameters are all less than until; This is a preset value for amplitude control accuracy. This is the preset value for phase control accuracy.

6. The secondary radar system calibration method for a digital phased array system with antenna coupling prior as described in claim 1, characterized in that, Step 4 includes: Step 401: Initialize the actual control parameter set for waveform, frequency point, and channel receiving amplitude and phase, initially set to 0. ; Step 402: Use the received amplitude and phase control actual parameter set Control the secondary radar system to operate in the first stage The waveform, the first It operates at a specific frequency and transmits signals through the calibration channel, while the TR channel acquires current amplitude and phase data. ; Step 403: Use the amplitude and phase theory target control parameter set , No. Waveform, number Subtracting the amplitude and phase data acquired in step 402 from the received amplitude and phase data of all channels at the operating frequency point yields the received amplitude and phase compensation parameters. and use compensation parameters Update target parameter set ; Step 404: Repeat steps 402 and 403 to calculate the set of received amplitude and phase control parameters for all waveforms, operating frequencies, and the TR channel. ; Obtain the complete waveform, operating frequency, amplitude, and phase control parameter set of the TR channel. .

7. The secondary radar system calibration method based on a digital phased array system with antenna coupling prior as described in claim 1, characterized in that, After step 4, the following is also included: When the secondary radar system is working, it dynamically updates the current working waveform, frequency point, and the actual control parameter set of amplitude and phase for transmission and reception of the channel.

8. The secondary radar system calibration method for a digital phased array system with antenna coupling prior as described in claim 7, characterized in that, When the secondary radar system is operating, it dynamically updates the current operating waveform, frequency point, and the actual control parameter set for the amplitude and phase of the transmission and reception channels, including: The secondary radar system based on the current waveform and frequency Using the actual control parameter set of amplitude and phase Control the phased array antenna to transmit and receive signals, and complete the current waveform according to steps 302, 303, 402, and 403. Operating frequency Full-channel transmit and receive amplitude and phase compensation parameters calculate; Use the obtained Update current waveform Frequency Index amplitude and phase, control the target parameter set for amplitude and phase. Waveform transmission and reception control is performed using the updated set of amplitude and phase target parameters.

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