A Method and Device for Controlling the Radiation Pattern of a Large Phased Array Antenna in Orbit

Abstract

The present invention discloses a method and device for regulating the on-orbit radiation pattern of a large phased array antenna, belonging to the field of antennas, including: proposing two types of optimization models, including a local distance ambiguity control optimization model and a polarization mode optimization model, respectively calculating the weighting factors under the local distance ambiguity control optimization model and the weighting factors under the polarization mode optimization model; based on the weighting factors under the local distance ambiguity control optimization model or the weighting factors under the polarization mode optimization model, solving for the optimal parameters through a convex optimization problem to obtain the optimal weighting factors; constructing a three-level wave control architecture, and calculating and distributing wave control codes based on the optimal weighting factors. The present invention greatly improves the accuracy of the measured antenna radiation pattern through the three-level wave control architecture and ensures the suppression effect of the distance ambiguity method.

Description

Technical Field

[0001] The present invention relates to the field of antennas, and in particular to a method and device for regulating the in-orbit radiation pattern of a large phased array antenna. Background Art

[0002] Large phased array antennas are mainly applicable to microwave remote sensing systems for earth observation, and obtain ground object information by transmitting and receiving electromagnetic waves. However, antennas generally have sidelobes, which can transmit and receive range-ambiguous signals, resulting in range ambiguity in the microwave remote sensing system. Range ambiguity is a key problem in microwave imaging, which will deteriorate the image quality and affect the acquisition and interpretation of ground object information.

[0003] To address the range ambiguity problem in microwave systems, an antenna radiation pattern shaping method has been proposed, which is mainly divided into three categories. The first category is the traditional antenna radiation pattern shaping method, which forms a static beam pointing based on the amplitude / phase adjustment of fixed weights. The second category is the adaptive antenna radiation pattern shaping method, which dynamically adjusts the weights according to the environment to maximize the signal-to-interference-plus-noise ratio (SINR), such as the minimum variance distortionless response (MVDR) and linearly constrained minimum variance (LCMV). The third category is the antenna radiation pattern shaping based on optimization algorithms, which solves the weights by optimizing the objective function (such as gain maximization and sidelobe suppression). However, to implement the antenna radiation pattern shaping technology in orbit, the calculation and distribution of wave control codes are required. According to the antenna radiation pattern requirements (such as main lobe gain and sidelobe suppression), the phase, attenuation, and delay parameters of each wave control component, that is, the wave control codes, are calculated at high speed. Then, the calculated wave control codes are quickly and synchronously distributed to nearly a thousand wave control components. Finally, the wave control codes are locally loaded into the wave control components to drive hardware such as phase shifters and attenuators to perform beam shaping. The existing wave control code calculation and distribution technologies mainly have the following limitations: ① Insufficient calculation efficiency. The traditional wave control system adopts a centralized calculation architecture and needs to process the weight parameters of thousands of TR components, resulting in significant calculation delays. For example, some solutions rely on general-purpose processors for optimization and are difficult to meet the dual requirements of low power consumption and high computing power of spaceborne systems. ② Poor distribution synchronization: The existing distribution layer mostly uses serial communication or low-speed parallel interfaces, resulting in wave control code transmission delays and synchronization errors. For large phased arrays (such as thousand-channel-level systems), synchronization errors will accumulate, seriously affecting the beam pointing accuracy and ambiguity suppression effect. ③ Low hardware integration: The existing wave control unit designs are scattered and lack radiation resistance, making it difficult to adapt to the extreme spaceborne environment. In addition, the local execution layer lacks an efficient cache and drive mechanism, resulting in limited wave control code switching speed and unable to support multi-mode fast switching. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a method and device for regulating the in-orbit radiation pattern of a large phased array antenna. The specific technical solutions are as follows:

[0005] A method for regulating the in-orbit radiation pattern of a large phased array antenna, comprising the following steps:

[0006] Step 101: Propose two types of optimization models, including a local distance ambiguity control optimization model and a polarization pattern optimization model, and calculate the weighting factors under the local distance ambiguity control optimization model and the weighting factors under the polarization pattern optimization model respectively;

[0007] Step 102: Based on the weighting factors under the local distance ambiguity control optimization model or the weighting factors under the polarization pattern optimization model, solve for the optimal parameters through a convex optimization problem to obtain the optimal weighting factors;

[0008] Step 103: Construct a three-level wave control architecture, calculate and distribute wave control codes based on the optimal weighting factors; the three-level wave control architecture includes: the first-level wave control architecture calculates wave control codes based on the optimal weighting factors; the second-level wave control architecture is used to synchronously distribute the wave control codes to the third-level wave control architecture; the third-level wave control architecture realizes the layout and effective control of the wave control codes inside the wave control components.

[0009] An in-orbit radiation pattern regulation device for a large phased array antenna, comprising:

[0010] An optimization model construction module, which proposes two types of optimization models, including a local distance ambiguity control optimization model and a polarization pattern optimization model, and calculates the weighting factors under the local distance ambiguity control optimization model and the weighting factors under the polarization pattern optimization model respectively;

[0011] A weighting factor calculation module, which solves for the optimal parameters through a convex optimization problem based on the weighting factors under the local distance ambiguity control optimization model or the weighting factors under the polarization pattern optimization model to obtain the optimal weighting factors;

[0012] A three-level wave control architecture, which calculates and distributes wave control codes based on the optimal weighting factors; the three-level wave control architecture includes: the first-level wave control architecture calculates wave control codes based on the optimal weighting factors; the second-level wave control architecture is used to synchronously distribute the wave control codes to the third-level wave control architecture; the third-level wave control architecture realizes the layout and effective control of the wave control codes inside the wave control components.

[0013] An electronic device, comprising: one or more processors; a memory for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the method described above.

[0014] A computer-readable storage medium, on which executable instructions are stored, and when the instructions are executed by a processor, the processor implements the method described above.

[0015] The present invention has the following beneficial effects:

[0016] The present invention proposes a local distance ambiguity control optimization model and a multi-polarization mode optimization model, which for the first time transform the traditional non-convex optimization problem into a convex optimization problem, and can accurately reduce the distance ambiguity sidelobe. On this basis, a three-stage beam control architecture for the antenna system is designed: the first-stage beam control is located inside the payload cabin to achieve real-time high-precision calculations of various error compensations, beamforming weights, etc.; the second-stage beam control is located outside the cabin antenna system to achieve high-speed distribution of beam control codes; the third beam control component is located inside the beam control component to achieve the final layout and activation of beam control codes. Through the designed three-stage beam control architecture, the accuracy of the measured antenna pattern is greatly improved, and the suppression effect of the distance ambiguity method is ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is the block diagram of the beam control single machine of the first-stage beam control architecture;

[0018] Figure 2 is the circuit diagram of the second-stage beam control architecture;

[0019] Figure 3 is the structure diagram of the in-orbit pattern control device of the phased array antenna of a certain on-orbit satellite;

[0020] Figure 4 is the comparison between the measured pattern and the theoretical pattern of a certain satellite working mode. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0022] According to an embodiment of the present invention, the present invention proposes a method for controlling the in-orbit pattern of a large phased array antenna, including the following steps:

[0023] Step 101: Propose two types of optimization models, including a local distance ambiguity control optimization model and a polarization mode optimization model, for suppressing distance ambiguity in different situations;

[0024] Among them, the local distance ambiguity control optimization model is used for the situation where the global characteristics may meet the requirements but the local characteristics still need to be optimized under the condition that the distance ambiguity is extremely strong.

[0025] The polarization mode optimization model is used to deal with the situation where, in different polarization modes, the ambiguity energy, signal energy, and the backscattering coefficient of the target usually change with the polarization method. Therefore, when strictly defining the optimization of multi-polarization range ambiguity performance, it is necessary to modify the local range ambiguity control optimization model. The two types of models are applicable to different scenarios and need to be selected according to the actual situation. The local range ambiguity control optimization model is applicable to the extreme situation where the range ambiguity is extremely strong, while the polarization mode optimization model takes into account the polarization characteristics on the basis of the local range ambiguity control optimization model and is used when the system operates in the polarization mode.

[0026] (1) Local range ambiguity control optimization model

[0027] There are usually two criteria for evaluating the range ambiguity level: global ambiguity characteristics and local ambiguity characteristics. In the optimization, the change trends of the two are not exactly the same. Therefore, in the case of extremely strong range ambiguity, it may occur that the global characteristics meet the requirements but the local characteristics still need to be optimized. Therefore, it is necessary to introduce the local range ambiguity control optimization model for the following corrections:

[0028] ;

[0029] where, is the optimization objective, represents the weighting factor, is the energy of the target echo signal, is the range ambiguity correction matrix, is a single angle, is the ambiguity matrix corresponding to the single angle, is the sign function, is the excitation factor, is a positive constant factor, is the real part extraction function, is the matrix conjugate. represents the weighting factor corresponding to solving the minimum value , represents the weighting factor obtained in the k-th iteration.

[0030] (2) Polarization mode optimization model

[0031] In actual situations, the values of the backscattering coefficient of the target, the signal echo energy, and the range ambiguity energy usually change with polarization. Therefore, when strictly defining the optimization of multi-polarization range ambiguity performance, it is necessary to introduce the polarization mode optimization model to modify the original problem, as follows:

[0032] ;

[0033] where, is the energy of the target echo signal in the polarization mode, is the ambiguity matrix at a single angle in the polarization mode, and is a constant.

[0034] Step 102: Based on the weighting factors calculated by the above-mentioned optimized model, use the CVX convex optimization toolbox provided in the MATLAB software to solve the optimal parameters of the above convex optimization problem, and obtain the optimal weighting factor W. Use this optimal weighting factor to perform amplitude-phase weighting on the phased array antenna, and then realize the on-orbit pattern regulation of the phased array antenna. The rest of the parameters are known quantities.

[0035] Step 103: Construct a three-level wave control architecture, and calculate and distribute the wave control code based on the optimal weighting factor; the three-level wave control architecture includes: the first-level wave control architecture is the calculation layer, using a wave control single machine to complete the calculation of the optimal weighting factor, that is, the wave control code; the second-level wave control architecture is the distribution layer, using wave control units to synchronously distribute the wave control code to the third-level wave control architecture; the third-level wave control architecture is the local execution layer, using wave control components to realize the layout and activation control of the wave control code inside the wave control components.

[0036] The three-level wave control architecture of the present invention is used to calculate the wave control code from the optimized optimal weighting factor W, and distribute the wave control code into the phased array antenna, and finally obtain the expected antenna pattern. The function of the three-level wave control architecture is to obtain and calculate wave control instructions and high-speed distribution of wave control codes. The specific architecture implementation method is as follows:

[0037] The first-level wave control architecture is the calculation layer, using an in-cabin wave control single machine to complete the calculation of the optimal weighting factor, and further complete the accurate generation and dynamic reconstruction of multiple beams. The phased array antenna uses digital phase shifters. The core calculation layer of this architecture uses a high-computing-power FPGA to calculate the phase shift angle of each unit in the phased array antenna through the optimal weighting factor, intercept the calculation result according to the actual control bits of the phase shifter, and query the non-linear curve of the phase shifter to drive the phase shifter to shift, and finally complete the high-speed and high-precision calculation of the wave control code. The calculation includes error compensation data, beam pointing parameters, and beam shaping weights. At the same time, the first-level wave control architecture is responsible for providing wave control clocks, working timings, and receiving telemetry information data from the second-level wave control architecture. The composition of the in-cabin wave control single machine is as Figure 1. The FPGA serves as the main computing unit, and the data PROM and FLASH are used to pre-store various error compensation data and beam weighting (shaping) weight data. During on-orbit applications, the FPGA reads the error compensation data, and at the same time receives the upper-level wave control instructions (including beam pointing parameters and beam weight selection parameters). The analog switch in cooperation with the AD sampling is used to obtain analog telemetry data, such as voltage telemetry, etc.; the differential receiver is used to obtain digital telemetry, such as temperature telemetry, antenna array surface digital telemetry, etc.; the differential driver is used to distribute the calculated wave control codes. Various error data are stored in the "PROM" and "FLASH". The PROM is non-erasable, and the FLASH is erasable and supports on-orbit uploading; the crystal oscillator is a component used to generate a stable frequency signal and provide an accurate clock reference. It completes the high-speed and high-precision calculation of the wave control codes and distributes them in parallel to the wave control units of each second-level wave control architecture through the differential driver.

[0038] The second-level wave control architecture is a high-speed distribution layer, which uses high-speed and high-precision aerospace-grade wave control units to ensure the high-precision synchronization of the wave control signals of nearly a thousand wave control components of the third-level wave control architecture. The wave control unit is a bridge connecting the in-cabin wave control single machine and the third-level component-level wave control components. It receives the wave control code data, timing signals, and other control signals from the in-cabin wave control single machine, drives and distributes them to the corresponding wave control components, and at the same time obtains the array surface telemetry data and returns it to the in-cabin wave control single machine. The first-level wave control architecture receives the telemetry information from the second-level wave control architecture to monitor the working state of the antenna and whether there are any abnormalities. To improve the integration and meet the environmental condition requirements of the wave control unit, the wave control unit circuit selects a wave control circuit with radiation resistance indicators to implement the control function. The detection data sending circuit receives the external serial signal, i.e., data 1 signal, through the mode parsing circuit, generates multiple signals for the control of the backend wave control components. The detection data sending circuit can also implement the AD acquisition of analog quantities through the AD acquisition circuit and collect digital bites_i through the digital quantity acquisition circuit. The detection data sending circuit sends back data 2 to the outside according to the mode requirements. This data 2 is sent to the third-level wave control components for distributing the wave control codes and at the same time outputs the telemetry data to the first-level wave control architecture. The internal block diagram of the circuit is as Figure 2 shown. Among them, the input pin of the gating generation circuit inputs the clock signal; the synchronization pin represents the enabling control; the output cp is for timing distribution; among them, the clock signal and the enabling control come from the crystal oscillator system of the first-level wave control architecture; the timing distribution goes to the third-level wave control architecture; the AD acquisition circuit acquires the data of the third-level wave control architecture; the digital quantity acquisition circuit acquires the data from the third-level wave control architecture; data 1 is the wave control code transmitted from the first-level wave control architecture; data 2 is the wave control code distributed to the third-level wave control architecture; the output is the telemetry data output to the first-level wave control architecture.

[0039] The third level is the local execution layer, which proposes an execution architecture of "cache + driver + phase shift + attenuation" and adopts aerospace-grade miniaturized high-speed wave control components. The third-level wave control architecture is used to implement the layout and effective control of wave control codes inside the wave control components. The wave control components are located inside the antenna. The wave control components are responsible for receiving the signals corresponding to this wave control component from the second-level wave control unit and completing the serial-parallel conversion of the wave control codes. According to the control timing signals, the wave control components complete the control of the transmitting, receiving, and load states and perform rapid switching of the transmit / receive wave control codes.

[0040] Figure 3 It represents the overall architecture. The radar monitoring timer is used to monitor the clock accuracy. The wave control single machine is the first-level wave control architecture, the wave control unit is the second-level wave control architecture. There are a total of 48 wave control units. The two-channel T / R delay amplifier is the wave control component, and each wave control unit is connected to two wave control components.

[0041] Embodiment 1

[0042] The embodiment is an on-orbit satellite antenna system based on the above wave control architecture. To achieve high-precision high-speed calculation and fast distribution of wave control codes, this single satellite is equipped with 1 first-level wave control single machine, 48 second-level wave control units, and 352 third-level wave control components, ensuring that the synchronization accuracy of the wave control signals of the wave control components is less than 1 ns, the wave control code distribution time is less than 0.5 ns, and the wave control code effective time is less than 0.5 ns.

[0043] Embodiment 2

[0044] Using the above method and device can achieve precise control of the antenna pattern, effectively reduce the shape difference between the actual pattern and the ideal target pattern, and ensure the suppression effect of system range ambiguity. Figure 4 It is a comparison between the measured pattern and the theoretical pattern of a certain wave position in the working mode of this satellite, indicating that the implementation effect of the theoretical pattern is good, the deviation of the range ambiguity suppression degree relative to the theoretical result is less than 0.8 dB, and the system range ambiguity is significantly improved.

[0045] The present invention also provides an electronic device, including: one or more processors; a memory for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the method described above.

[0046] The present invention also provides a computer-readable storage medium, on which executable instructions are stored, and when the instructions are executed by a processor, the processor implements the method described above.

[0047] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above description is only for the specific embodiments of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for adjusting the in-orbit radiation pattern of a large phased array antenna, characterized in that It includes the following steps: Step 101: Propose two types of optimization models, including a local distance fuzzy control optimization model and a polarization mode optimization model, and calculate the weighting factors under the local distance fuzzy control optimization model and the weighting factors under the polarization mode optimization model respectively; Step 102: Based on the weighting factor under the local distance fuzzy control optimization model or the weighting factor under the polarization mode optimization model, solve for the optimal parameters through a convex optimization problem to obtain the optimal weighting factor; Step 103: Construct a three-level wave control architecture, and calculate and distribute wave control codes based on the optimal weighting factor; The three-level wave control architecture includes: The first-level wave control architecture calculates wave control codes based on the optimal weighting factor; The second-level wave control architecture is used to synchronously distribute the wave control codes to the third-level wave control architecture; The third-level wave control architecture realizes the deployment and activation control of the wave control codes inside the wave control components.

2. A method for regulating the in-orbit radiation pattern of a large phased array antenna according to claim 1, characterized in that, Among them, The local distance fuzzy control optimization model is used to optimize local characteristics and calculate the weighting factor under the local distance fuzzy control optimization model; The polarization mode optimization model considers polarization characteristics on the basis of the local distance fuzzy control optimization model, and calculates the weighting factor under the polarization mode optimization model in the polarization mode.

3. The method for regulating the in-orbit radiation pattern of a large phased array antenna according to claim 2, wherein The local distance fuzzy control optimization model is specifically: ； Among them, is the optimization objective, represents the weighting factor, is the energy of the target echo signal, is the range ambiguity correction matrix, is a single angle, is the ambiguity matrix corresponding to the single angle, is the sign function, is the excitation factor, is the positive constant factor, is the real part taking function, is the matrix conjugate, represents the weighting factor corresponding to solving the minimum value , represents the weighting factor obtained in the k-th iteration.

4. A method for adjusting the on-orbit radiation pattern of a large phased array antenna according to claim 2, characterized in that, The polarization mode optimization model is specifically: ； Among them, is the optimization objective, represents the weighting factor, is the energy of the target echo signal in the polarization mode, is the sign function, is the excitation factor, is a normal constant factor, is the real part extraction function, is the matrix conjugate, represents the corresponding weighting factor when solving the minimum value , represents the weighting factor obtained in the k-th iteration, is the ambiguity matrix at a single angle in the polarization mode, and are constants.

5. A method for adjusting the in-orbit radiation pattern of a large phased array antenna according to claim 1, characterized in that, The first-level wave control architecture is the calculation layer, using a single wave control machine; The second-level wave control architecture is the distribution layer, using wave control units; The third-level wave control architecture is the local execution layer, using wave control components.

6. A method for regulating the in-orbit radiation pattern of a large phased array antenna according to claim 5, characterized in that The calculation layer calculates the phase shift angle of each antenna element in the phased array antenna through the optimal weighting factor, intercepts the calculation result according to the actual control bits of the phase shifter, and queries the non-linear curve of the phase shifter to drive the phase shifter to shift, completing the calculation of the wave control code.

7. A method for adjusting the in-orbit radiation pattern of a large phased array antenna according to claim 5, characterized in that, The wave control unit connects the single wave control machine and the wave control components, receives the wave control codes and timing signals from the single wave control machine, drives and distributes them to the corresponding wave control components, and at the same time obtains the array telemetry data and returns it to the single wave control machine.

8. A method for regulating the in-orbit radiation pattern of a large phased array antenna according to claim 6, characterized in that, The wave control component receives the wave control code corresponding to this wave control component from the wave control unit and completes the serial-parallel conversion.

9. A method for adjusting the on-orbit radiation pattern of a large phased array antenna according to claim 5, characterized in that, The wave control component uses a two-channel T / R delay amplifier, and each wave control unit connects two wave control components.

10. A method for adjusting the in-orbit radiation pattern of a large phased array antenna according to claim 5, characterized in that, It includes 1 first-level wave control single machine, 48 second-level wave control units, and 352 third-level wave control components. The synchronization accuracy of the wave control signals of the wave control components is less than 1 ns, the wave control code distribution time is less than 0.5 ns, and the wave control code activation time is less than 0.5 ns.

11. A device for adjusting the in-orbit radiation pattern of a large phased array antenna, characterized in that, It includes: An optimization model construction module, which proposes two types of optimization models, including a local distance fuzzy control optimization model and a polarization mode optimization model, and calculates the weighting factors under the local distance fuzzy control optimization model and the weighting factors under the polarization mode optimization model respectively; A weighting factor calculation module, which based on the weighting factor under the local distance fuzzy control optimization model or the weighting factor under the polarization mode optimization model, solves for the optimal parameters through a convex optimization problem to obtain the optimal weighting factor; Three-level wave control architecture, calculating and distributing wave control codes based on optimal weighting factors; the three-level wave control architecture includes: the first-level wave control architecture calculates wave control codes based on optimal weighting factors; the second-level wave control architecture is used to synchronously distribute the wave control codes to the third-level wave control architecture; the third-level wave control architecture realizes the layout and effective control of the wave control codes within the wave control components.

12. An electronic device, characterized in that, including: one or more processors; a memory for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the method according to any one of claims 1 to 10.

13. A computer-readable storage medium, characterized in that, An executable instruction is stored thereon, and when the instruction is executed by a processor, the processor implements the method according to any one of claims 1 to 10.

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