SAR (Synthetic Aperture Radar) linear frequency modulation signal predistortion compensation device

Abstract

The invention relates to the technical field of radars, in particular to an SAR radar chirp signal predistortion compensation device, which comprises a control module used for receiving a control instruction and generating a driving signal in response to the control instruction; the microwave module is connected with the control module and is used for responding to the driving signal, determining to receive a radar transmitting signal and performing channel selection and down-conversion processing on the radar transmitting signal based on the driving signal so as to output an intermediate frequency signal; the acquisition module is connected with the microwave module and is used for performing high-speed acquisition on the intermediate-frequency signal to obtain waveform data after frequency conversion; and the correction updating module is connected with the acquisition module and the control module, and is used for processing the waveform data after frequency conversion to a baseband waveform, comparing the baseband waveform with ideal waveform data, calculating a phase error, and generating pre-distortion correction data based on the phase error so as to update the emission waveform of the radar. According to the method, the accuracy and reliability of a measurement result can be improved under low-cost budget, so that the performance of the radar is effectively improved.

Description

Technical Field

[0001] The embodiments of this application relate to the field of radar technology, and in particular to a predistortion compensation device for linear frequency modulated (LFM) signals of SAR radar. Background Technology

[0002] In Synthetic Aperture Radar (SAR) systems, linear frequency modulated (LFM) signals are crucial for achieving high-resolution imaging. However, the nonlinear characteristics of devices such as power amplifiers and digital-to-analog converters in the radar transmit link introduce amplitude and phase distortion, causing the actual transmitted signal to deviate from the ideal waveform. This distortion can lead to problems such as increased sidelobe levels after pulse compression and main lobe broadening, severely degrading the radar's range resolution and imaging quality.

[0003] To compensate for distortion, existing technologies mainly follow two paths: one is predistortion mapping technology based on instrument measurement, but this method relies on expensive instruments such as high-speed oscilloscopes, the system setup is complex, and the measurement channel itself introduces noise, affecting the correction accuracy; the other is model-based predistortion technology, which avoids expensive instruments, but the established mathematical model is difficult to track the time-varying characteristics of the device with factors such as temperature and aging, and the computational complexity is high, with the risk of model mismatch.

[0004] Therefore, how to reduce reliance on models and improve the accuracy and reliability of measurement results under low-cost budgets, thereby effectively improving radar performance, is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] To address the aforementioned technical problems, embodiments of this application propose a predistortion compensation device for SAR radar linear frequency modulated signals, which aims to reduce reliance on models and improve the accuracy and reliability of measurement results under low-cost budget, thereby effectively enhancing radar performance.

[0006] To achieve the above objectives, embodiments of this application propose a predistortion compensation device for SAR radar linear frequency modulated signals. The device is integrated into a single unit and includes: a control module, a microwave module, an acquisition module, and a correction and update module. The control module is used to receive control commands and generate drive signals in response to the control commands; wherein the drive signals are used to drive the radio frequency switch. The microwave module, connected to the control module, is used to respond to the drive signal, determine the received radar transmitted signal, and perform channel selection and down-conversion processing on the radar transmitted signal based on the drive signal to output an intermediate frequency signal. The acquisition module, connected to the microwave module, is used for high-speed acquisition of intermediate frequency signals to obtain the frequency-converted waveform data; The calibration and update module, connected to the acquisition module and the control module, is used to process the frequency-converted waveform data into a baseband waveform, compare it with the ideal waveform data, calculate the phase error, and generate pre-distortion correction data based on the phase error to update the radar's transmitted waveform.

[0007] To achieve the above objectives, embodiments of this application propose a method for predistortion compensation of SAR radar linear frequency modulated signals, the method comprising the following steps: It receives control commands and generates drive signals in response to the control commands; wherein the drive signals are used to drive the radio frequency switch. In response to the drive signal, the received radar transmitted signal is determined, and the radar transmitted signal is channel selected and down-converted based on the drive signal to output an intermediate frequency signal; The intermediate frequency signal is acquired at high speed to obtain the waveform data after frequency conversion; The frequency-converted waveform data is processed into a baseband waveform and compared with the ideal waveform data to calculate the phase error. Based on the phase error, pre-distortion correction data is generated to update the radar's transmitted waveform.

[0008] To achieve the above objectives, embodiments of this application also propose a SAR radar linear frequency modulated signal predistortion compensation device, characterized in that the device has an integrated box structure, including: a housing, and multiple modules integrated inside the housing; the multiple modules include: a control module, a microwave module, an acquisition module, and a correction and update module; the device is capable of implementing the SAR radar linear frequency modulated signal predistortion compensation method as described above.

[0009] To achieve the above objectives, embodiments of this application also propose a computer-readable storage medium storing a computer program that, when executed by a processor, can implement a SAR radar linear frequency modulation signal predistortion compensation method as described above.

[0010] This application proposes a SAR radar linear frequency modulated signal predistortion compensation device. A control module receives control commands and generates a drive signal in response. Since the drive signal drives an RF switch, a microwave module connected to the control module responds to the drive signal, determines the radar transmitted signal to be received, and performs channel selection and down-conversion processing on the radar transmitted signal based on the drive signal to output an intermediate frequency (IF) signal. Then, an acquisition module performs high-speed acquisition of the IF signal to obtain the frequency-converted waveform data. A correction and update module processes the frequency-converted waveform data to a baseband waveform, compares it with ideal waveform data, calculates the phase error, and generates predistortion correction data based on the phase error to update the radar signal. The proposed solution addresses the high computational complexity of deriving predistortion functions from pre-configured models in related technologies. It acquires waveform data from different frequency conversions, calculates the error between the waveform and the ideal waveform, and then corrects this error in reverse, thereby reducing reliance on models and ensuring the accuracy and reliability of measurement results. Since the device integrates a control module, microwave module, acquisition module, and correction and update module, it eliminates the need for multiple high-value instruments and a large predistortion mapping table, thus reducing equipment costs. Therefore, this solution reduces reliance on models and improves the accuracy and reliability of measurement results within a low-cost budget, effectively enhancing radar performance.

[0011] Optionally, the control module includes an industrial control unit and a logic control unit; the industrial control unit is used to receive control commands through a human-machine interface; the logic control unit is used to receive macro-control commands and generate drive signals of preset levels to control the microwave module.

[0012] Optionally, the microwave module specifically includes: an RF switching unit, used to receive radar transmitted signals under the drive of a drive signal, and automatically select and switch to the target signal channel corresponding to the working frequency band based on the working frequency band of the radar transmitted signals to obtain RF signals; and a mixing and filtering unit, used to mix and down-convert the RF signals and the local oscillator signals, and output intermediate frequency signals through filtering.

[0013] Optionally, the RF switching unit integrates single-pole four-throw electromechanical switches for various radar frequency bands to achieve automatic selection and switching of signal channels.

[0014] Optionally, the downconversion module and the filter module in the mixing and filtering unit are replaceable components to adapt to different radar frequency bands.

[0015] Optionally, the acquisition module specifically includes: a high-speed analog-to-digital converter for high-speed acquisition and conversion of intermediate frequency signals to obtain digital signals corresponding to the frequency-converted waveform data; and a data storage unit for storing the digital signals corresponding to the frequency-converted waveform data.

[0016] Optionally, a data interaction module and a power supply module are included. The data interaction module is used to interconnect the various modules in the device through a gigabit network switch to build an internal local area network and realize data interaction between the modules. The power supply module is used to provide stable power to each module in a two-stage multi-path power supply mode combining switching power supply and linear power supply, while suppressing ripple noise. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies of this application will be briefly introduced below. Obviously, the following drawings are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The drawings described herein are only used to explain this application and are not intended to limit this application.

[0018] Figure 1 This is a structural diagram of a SAR radar linear frequency modulation signal predistortion compensation device provided in one embodiment of this application; Figure 2 This is a flowchart of a SAR radar linear frequency modulation signal predistortion compensation method provided in one embodiment of this application; Figure 3 This is a front view of a SAR radar linear frequency modulation signal predistortion compensation device provided in one embodiment of this application; Figure 4 This is a side view of a SAR radar linear frequency modulation signal predistortion compensation device provided in one embodiment of this application; Figure 5 This is a rear view of a SAR radar linear frequency modulation signal predistortion compensation device provided in one embodiment of this application; Figure 6 This is a schematic diagram of a SAR radar linear frequency modulation signal predistortion compensation system provided in another embodiment of this application; Figure 7 This is a schematic diagram of the structure of an electronic device provided in another embodiment of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. Those skilled in the art will understand that many technical details have been presented in the embodiments of this application to facilitate better understanding. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of this application. The following embodiments can be combined with and referenced by each other without contradiction.

[0020] In radar systems, especially high-resolution SAR radar, the quality of the transmitted waveform directly determines the system's performance indicators, such as range resolution, velocity resolution, and imaging quality. Linear frequency modulation (LFM) signals, due to their large time-bandwidth product, enable high-resolution pulse compression and are widely used in modern radar. However, LFM signals are extremely sensitive to nonlinear distortion in the transmission link. The inherent nonlinear characteristics of components in the transmission link, such as digital-to-analog converters (DACs), power amplifiers, and mixers, introduce amplitude and phase distortion, causing the actual transmitted LFM signal to deviate from the ideal LFM characteristics.

[0021] This distortion leads to a series of serious consequences: pulse compression results in higher sidelobe levels, main lobe broadening, and sidelobe asymmetry, severely degrading the radar's range resolution and weak target detection capabilities. Simultaneously, out-of-band spectral spread increases interference with other electronic devices, affecting electromagnetic compatibility. Traditionally, to ensure radar performance, devices such as power amplifiers need to operate in a backup range with better linearity but lower efficiency, which limits the radar's effective range and overall efficiency.

[0022] To overcome the aforementioned problems, waveform predistortion correction technology has emerged. The core idea of ​​this technology is to pre-compensate the baseband digital waveform during the signal generation stage with distortion characteristics opposite to those of the transmission link, so that the output signal after passing through a non-ideal transmission link is as close as possible to the ideal waveform. Currently, mainstream predistortion technologies are mainly divided into two categories, but both have significant shortcomings: The first type is predistortion mapping technology based on instrument measurement. This approach directly acquires the radar's final output analog signal using expensive instruments such as high-sampling-rate, high-bandwidth digital oscilloscopes, compares it with an ideal digital baseband signal, calculates the distortion, and constructs a predistortion mapping table (i.e., a lookup table) based on the input-output characteristics. However, this approach has significant drawbacks: First, it relies on various high-value instruments such as mixers, spectrum analyzers, and high-speed oscilloscopes to build the test environment, resulting in high system costs, complex operation, and high requirements for personnel expertise; second, the noise and distortion of the feedback channel (i.e., the measurement system) itself introduce additional errors, contaminating the data used to update the lookup table, thus leading to a decrease in calibration accuracy.

[0023] The second category is model-based predistortion compensation techniques. This approach attempts to establish a mathematical model of the transmission channel (such as a power amplifier or DAC) using system identification technology and then calculates the inverse function of this model as the predistorter. While this method avoids dependence on expensive measuring instruments, it has inherent drawbacks: First, model mismatch. The characteristics of radar internal components dynamically drift with factors such as temperature, component aging, operating frequency, and power supply voltage. A fixed mathematical model cannot accurately track these time-varying characteristics, leading to a decrease in correction effectiveness over time. Second, high computational complexity. For modern radar systems with high frequency, wide bandwidth, and long time span, establishing an accurate model is already very difficult; the real-time solution of its inverse function is even more computationally intensive, making it difficult to meet the real-time requirements of engineering applications.

[0024] In summary, existing technologies either suffer from high costs, operational complexity, and the introduction of measurement noise due to reliance on high-end instruments, or suffer from poor adaptability and computational complexity due to inherent limitations of the models. Therefore, how to reduce reliance on models and improve the accuracy and reliability of measurement results within a low-cost budget, thereby effectively enhancing radar performance, is a pressing technical problem that needs to be solved.

[0025] In view of this, this application proposes a predistortion compensation device for linear frequency modulated (LFM) signals of SAR radar, which can reduce the dependence on models and improve the accuracy and reliability of measurement results under low cost budget, thereby effectively improving the performance of radar.

[0026] like Figure 1 As shown, Figure 1 This is a structural diagram of a SAR radar linear frequency modulated signal predistortion compensation device according to one embodiment of this application. The device includes: a control module 110, a microwave module 120, an acquisition module 130, and a correction and update module 140. Optionally, the device also includes: a data interaction module 150 and a power supply module 160.

[0027] For example, the control module 110 is connected to the microwave module 120, the acquisition module 130, the correction and update module 140, and the data interaction module 150, respectively, and can be used to send control signals to each module. The microwave module 120 is connected to the control module 110 and the acquisition module 130, and the acquisition module 130 is connected to the microwave module and the data interaction module 150; the acquisition module 130 establishes a connection with the correction and update module 140 through the data interaction module 150. The power supply module 160 supplies power to each module in the SAR radar linear frequency modulated signal predistortion compensation device.

[0028] The control module 110 is used to receive control commands and generate drive signals in response to the control commands.

[0029] The drive signal is used to drive the radio frequency switch.

[0030] In one possible embodiment, the control module includes an industrial control unit and a logic control unit; the industrial control unit is used to receive control commands through a human-machine interface; the logic control unit is used to receive macro-control commands and generate a preset level drive signal to control the microwave module.

[0031] For example, the preset level can be a TTL level.

[0032] For example, the industrial control unit in the control module can run various calibration software to provide a human-machine interface; and receive control commands through the human-machine interface. For instance, the calibration software may include development environments such as QT, LabVIEW, and Matlab, thereby providing computing power support and a human-machine interface.

[0033] For example, the logic control unit receives the control command and generates a TTL-level drive signal to control a microwave module, such as an RF switch within the microwave module. The logic control unit can be a main control board unit, based on an EPM570 chip, that receives control commands via a USB interface and converts them into TTL-level control signals to drive the RF switch in the microwave system.

[0034] Understandably, the control module 110 can achieve stable and reliable transmission of control commands, has a high degree of automation, and simplifies manual operation.

[0035] The microwave module 120, connected to the control module 110, is used to determine the received radar transmission signal in response to the drive signal, and to perform channel selection and down-conversion processing on the radar transmission signal based on the drive signal to output an intermediate frequency signal.

[0036] In one possible embodiment, the microwave module 120 specifically includes: a radio frequency switch unit, used to receive radar transmitted signals under the drive of a drive signal, and automatically select and switch to a target signal channel corresponding to the working frequency band based on the working frequency band of the radar transmitted signals to obtain a radio frequency signal; and a mixing and filtering unit, used to mix and down-convert the radio frequency signal and the local oscillator signal, and output an intermediate frequency signal through filtering.

[0037] In one possible embodiment, the radio frequency switching unit integrates single-pole four-throw electromechanical switches for multiple different radar frequency bands to achieve automatic selection and switching of signal channels.

[0038] For example, the radio frequency switch unit integrates a high-performance electromechanical switch, specifically a single-pole four-throw electromechanical switch that can operate in frequency bands covering DC-40GHz and DC-18GHz, thereby providing high flexibility and versatility for the device provided in the embodiments of this application.

[0039] For example, the RF switch unit receives the transmitted signal from the radar. Simultaneously, it receives a TTL-level drive signal from the main control board in the control system. Based on the operating frequency band of the radar's transmitted signal, the RF switch unit, under the control of the drive signal, automatically selects and switches from multiple alternative signal channels to the target signal channel that matches the current operating frequency band, thus replacing the traditional method of manually changing wiring or connecting multiple external signal sources.

[0040] Understandably, the RF switching unit enables automatic and precise switching of signal channels, avoiding errors and inconsistencies that may be introduced by manual wiring, and providing a stable and reliable RF signal for subsequent processing.

[0041] For example, the radio frequency switching unit may include a mixer and a bandpass filter. Various types of mixers can be integrated into the device to meet the adaptation requirements of different radar frequency bands.

[0042] For example, a mixer mixes the radio frequency signal output from the radio frequency switching unit with a local oscillator signal provided by an external signal source. By utilizing the nonlinear device, it completes the first frequency conversion of the input signal, downconverting it from a high frequency to a fixed intermediate frequency signal (e.g., downconverting to a frequency range of 4-5.6 GHz).

[0043] For example, the intermediate frequency (IF) signal obtained after downconversion will contain the desired components as well as spurious interference such as harmonics and cross-modulation. This signal is then filtered by a bandpass filter (e.g., a filter with a passband range of 3-5 GHz or 4-7 GHz). This filter effectively removes out-of-band noise and interference, extracting a clean, broadband IF signal that meets the requirements for subsequent acquisition.

[0044] In one possible embodiment, the downconversion module and the filtering module in the mixing and filtering unit are replaceable components to adapt to different radar frequency bands.

[0045] Understandably, since the downconversion and filtering modules in the mixing and filtering unit are replaceable components, it allows for the replacement of corresponding microwave components, such as the downconversion and filtering modules, based on different radar frequency bands and bandwidth requirements. The software platform is adaptable to various radar models and waveforms, thus replacing expensive general-purpose instruments, such as high-speed oscilloscopes, and reducing the overall system cost.

[0046] The acquisition module 130 is connected to the microwave module 120 and is used to acquire intermediate frequency signals at high speed to obtain the waveform data after frequency conversion.

[0047] In one possible embodiment, the acquisition module specifically includes: a high-speed analog-to-digital converter for high-speed acquisition and conversion of intermediate frequency signals to obtain digital signals corresponding to the frequency-converted waveform data; and a data storage unit for storing the digital signals corresponding to the frequency-converted waveform data.

[0048] Understandably, the acquisition module 130 is responsible for converting the analog intermediate frequency signal into a digital signal with high quality and storing it reliably.

[0049] For example, the sampling rate of the high-speed analog-to-digital converter (ADC) can be adjusted to convert intermediate frequency (IF) signals into digital signals; this high-speed ADC is designed to adapt to the characteristics of wideband radar signals. Specifically, its sampling rate is adjustable up to 10.4 Gsps (gigasamples per second), with an effective number of bits (ENOB) of at least 8 bits, and a storage depth of at least 3 MSa (megasamples). The high-speed ADC also supports external synchronous triggering.

[0050] For example, under the synchronous triggering of the control system, the high-speed analog-to-digital converter samples the analog intermediate frequency signal in real time at an extremely high sampling rate and converts it into a high-precision digital signal, thereby capturing the radar pulse waveform and ensuring the integrity of the waveform data after frequency conversion, providing the original data basis for subsequent accurate distortion analysis.

[0051] For example, the data storage unit uses the JESD204B interface to receive data and writes it to the solid-state drive in parallel after being cached by DDR3, thereby achieving high-speed, real-time, lossless data storage.

[0052] For example, the high-speed digital signal output from the ADC is first transmitted through the JESD204B standard high-speed serial interface. Subsequently, this data is temporarily stored in DDR3 memory. DDR3 memory acts as a cache, resolving the mismatch between the ADC's continuous high-speed output and the memory's write speed, thus achieving smooth data buffering. Finally, the data is written in parallel from the DDR3 cache to two M.2 interface solid-state drives.

[0053] The calibration update module 140, connected to the acquisition module 130 and the control module 110, is used to process the frequency-converted waveform data into a baseband waveform, compare it with the ideal waveform data, calculate the phase error, and generate pre-distortion correction data based on the phase error to update the radar's transmitted waveform.

[0054] For example, the correction update module 140 first receives frequency-converted waveform data sent from the acquisition module. This data is a digital signal obtained after down-conversion, filtering, and high-speed acquisition of the radar transmitted signal. The correction update module 140 processes the frequency-converted waveform data into a baseband waveform and compares it with pre-stored ideal waveform data to calculate the phase error between them. Given the phase error, inverse predistortion calculation can be performed to obtain a predistortion amount opposite to the phase error. Predistortion correction data is then generated based on this predistortion amount. The predistortion correction data may include amplitude and phase compensation information; when applied to the radar's baseband waveform, it can pre-cancele the distortion that will occur in the transmission link.

[0055] Understandably, the corrected waveform data is uploaded to the radar. When the radar transmits signals subsequently, it will use this updated waveform data with pre-distortion compensation to compensate for the distortion in the transmission link at the source, and finally output a linear frequency modulated signal that is closer to the ideal state.

[0056] It is also understood that the embodiments of this application collect the actual transmitted waveform of the radar, compare it with the ideal linear frequency modulated signal, calculate the phase error, and perform inverse phase pre-distortion compensation. This means that the distortion that may be introduced by the transmission channel (such as DAC, amplifier, etc.) has been canceled before the signal is transmitted. Therefore, the embodiments of this application can effectively correct the transmission link distortion problem, significantly reduce the sidelobe level after pulse compression, solve the problems of main lobe broadening and sidelobe asymmetry, greatly improve the radar's range resolution and weak target detection capability, and meet the stringent requirements of high-resolution SAR imaging.

[0057] The data interaction module 150 is used to interconnect the various modules in the device through a gigabit network switch to build an internal local area network and realize data interaction between the modules.

[0058] For example, the data interaction module 150 can interconnect the various modules in the SAR radar linear frequency modulation signal predistortion compensation device through a gigabit network switch; for example, by interconnecting the control module, acquisition module and other modules through a gigabit network switch, a high-speed and stable internal local area network is constructed, ensuring high-speed interaction between commands and data.

[0059] For example, the acquisition module acquires radar signals at a maximum rate of 10.4 Gsps, generating a massive data stream. This module uses a gigabit network to quickly and losslessly transfer the massive amount of raw waveform data from the acquisition module to a memory for storage, providing a data foundation for subsequent calibration and analysis. After calibration, the generated pre-distortion correction file is also transmitted back to the radar system via the network.

[0060] The power supply module employs a two-stage multi-channel power supply mode combining switching power supplies and linear power supplies to provide stable power to each module while suppressing ripple noise.

[0061] For example, the power module can adopt a two-stage multi-channel power supply mode that combines switching power supplies and linear power supplies. For instance, the path can be: external AC220V alternating current is first converted to DC24V, and then further converted to multiple low-voltage DC power supplies such as DC12V.

[0062] It is understood that the power module provided in this application embodiment can reduce the size and weight while suppressing power supply ripple noise, thereby providing stable power supply to each module and suppressing ripple noise, especially for noise-sensitive microwave modules (e.g., mixers in microwave modules) and acquisition modules (e.g., analog-to-digital converters in acquisition modules).

[0063] This application proposes a SAR radar linear frequency modulated signal predistortion compensation device. A control module receives control commands and generates a drive signal in response. Since the drive signal drives an RF switch, a microwave module connected to the control module responds to the drive signal, determines the radar transmitted signal to be received, and performs channel selection and down-conversion processing on the radar transmitted signal based on the drive signal to output an intermediate frequency (IF) signal. Then, an acquisition module performs high-speed acquisition of the IF signal to obtain the frequency-converted waveform data. A correction and update module processes the frequency-converted waveform data to a baseband waveform, compares it with ideal waveform data, calculates the phase error, and generates predistortion correction data based on the phase error to update the radar signal. The proposed solution addresses the high computational complexity of deriving predistortion functions from pre-configured models in related technologies. It acquires waveform data from different frequency conversions, calculates the error between the waveform and the ideal waveform, and corrects this error in reverse, thereby reducing reliance on models and ensuring the accuracy and reliability of measurement results. Since the device integrates a control module, microwave module, acquisition module, and correction / update module, it eliminates the need for multiple high-value instruments and a large predistortion mapping table, thus reducing equipment costs. Therefore, this solution reduces reliance on models and improves the accuracy and reliability of measurement results within a low-cost budget, effectively enhancing radar performance.

[0064] In summary, the SAR radar linear frequency modulated signal predistortion compensation device provided in this application, through its integrated hardware architecture and automated digital signal processing flow, effectively compensates for inherent hardware defects in the radar transmission link. Specifically, this application successfully transforms predistortion correction theory into a highly practical high-end test and support device. This device, through an automated closed-loop "acquisition-analysis-correction" process, effectively solves the key technical challenge of waveform distortion correction faced by radars in the development and mass production stages.

[0065] Another embodiment of this application proposes a SAR radar linear frequency modulated signal predistortion compensation method, applied to the SAR radar linear frequency modulated signal predistortion compensation device proposed in the above embodiment. The implementation details of the SAR radar linear frequency modulated signal predistortion compensation method proposed in this embodiment are described below. The following implementation details are provided for ease of understanding and are not essential for implementing this solution.

[0066] The specific process of the SAR radar linear frequency modulation signal predistortion compensation method proposed in this embodiment can be described as follows: Figure 2 As shown, it includes: Step 201: Receive control commands and generate drive signals in response to control commands.

[0067] The drive signal is used to drive the radio frequency switch.

[0068] Step 202: In response to the drive signal, determine the received radar transmitted signal, and perform channel selection and down-conversion processing on the radar transmitted signal based on the drive signal to output an intermediate frequency signal.

[0069] Step 203: High-speed acquisition of the intermediate frequency signal to obtain the waveform data after frequency conversion.

[0070] Step 204: The frequency-converted waveform data is processed into a baseband waveform and compared with the ideal waveform data to calculate the phase error. Based on the phase error, pre-distortion correction data is generated to update the radar's transmitted waveform.

[0071] For a detailed description of steps 201 to 204, please refer to the description related to the SAR radar linear frequency modulation signal predistortion compensation device in the above embodiments, which will not be repeated here.

[0072] This application proposes a method for predistortion compensation of SAR radar linear frequency modulated signals. First, a control module receives control commands and generates a drive signal in response. Then, a microwave module, responding to the drive signal, determines the received radar transmitted signal and performs channel selection and down-conversion processing on the radar transmitted signal based on the drive signal to output an intermediate frequency (IF) signal. Next, an acquisition module performs high-speed acquisition of the IF signal to obtain the frequency-converted waveform data. Finally, a correction and update module processes the frequency-converted waveform data into a baseband waveform, compares it with ideal waveform data, calculates the phase error, and generates predistortion based on the phase error. This application corrects data to update the radar's transmitted waveform. Unlike related technologies that require pre-configured models to derive predistortion functions, resulting in high computational complexity, this application can acquire waveform data from different frequency conversions, calculate the error between the waveform and the ideal waveform, and then correct this error in reverse. This reduces reliance on models while ensuring the accuracy and reliability of measurement results. Furthermore, it eliminates the need for multiple high-value instruments and a large predistortion mapping table, thus reducing equipment costs. Therefore, this solution reduces reliance on models and improves the accuracy and reliability of measurement results within a low-cost budget, thereby effectively enhancing radar performance.

[0073] like Figures 3 to 5 As shown, another embodiment of this application proposes a SAR radar linear frequency modulated signal predistortion compensation device. The device has an integrated box structure, including: a housing, and multiple modules integrated inside the housing; the multiple modules include: a control module, a microwave module, an acquisition module, and a correction and update module.

[0074] It is understood that the device proposed in this embodiment is a highly integrated special device. Its core design concept is to integrate the traditional test system, which consists of multiple discrete instruments, computers and complex wiring, into a robust and compact integrated box structure. All processes are automatically completed through software control, avoiding human error and simplifying the complex calibration work into a one-click operation, thereby improving the efficiency of pre-distortion compensation.

[0075] For example, the main body of the device provided in this application embodiment can be a housing, such as... Figures 3 to 5 As shown, the housing not only serves as a physical support and protective structure, but is also meticulously designed to optimize electromagnetic shielding and heat dissipation. This integrated design makes the equipment easy to move and deploy, and it can adapt well to different working environments such as laboratories, production workshops, or outdoor fields.

[0076] For example, all the functional modules required for pre-distortion compensation, such as a control module, microwave module, acquisition module, and correction and update module, can be integrated inside the housing. Optionally, a power supply module and a data interaction module can also be integrated.

[0077] For a detailed description of each of the above functional modules, please refer to the description related to the SAR radar linear frequency modulation signal predistortion compensation device in the above embodiments, which will not be repeated here.

[0078] The steps described above are for clarity only. In implementation, they can be combined into one step, or some steps can be broken down into multiple steps, as long as they involve the same logical relationship, they are all within the scope of protection of this application. Adding insignificant modifications or introducing insignificant designs to the algorithm or process, without changing the core design of the algorithm and process, are also within the scope of protection of this application.

[0079] Another embodiment of this application proposes a SAR radar linear frequency modulated signal predistortion compensation system. The details of this SAR radar linear frequency modulated signal predistortion compensation system are described below. The following implementation details are provided for ease of understanding and are not essential for implementing this example. Figure 6 This is a schematic diagram of the structure of a SAR radar linear frequency modulated signal predistortion compensation system proposed in this embodiment, including: The receiving and generating unit 610 is used to receive control commands and generate drive signals in response to the control commands; wherein the drive signals are used to drive the radio frequency switch. The determination and processing unit 620 is used to determine the received radar transmitted signal in response to the drive signal, and to perform channel selection and down-conversion processing on the radar transmitted signal based on the drive signal to output an intermediate frequency signal. The high-speed sampling unit 630 is used to acquire intermediate frequency signals at high speed to obtain the waveform data after frequency conversion; The comparison and update unit 640 is used to process the frequency-converted waveform data into a baseband waveform, compare it with the ideal waveform data, calculate the phase error, and generate pre-distortion correction data based on the phase error to update the radar's transmitted waveform.

[0080] It is not difficult to see that this embodiment is a system embodiment corresponding to the above method embodiments, and this embodiment can be implemented in conjunction with the above method embodiments. The relevant technical details and technical effects mentioned in the above method embodiments are still valid in this embodiment, and will not be repeated here to reduce repetition. Accordingly, the relevant technical details mentioned in this embodiment can also be applied to the above method embodiments.

[0081] It is worth mentioning that all modules and units involved in this embodiment are logical modules. In practical applications, a logical unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. Furthermore, to highlight the innovative aspects of this application, this embodiment does not introduce units that are not closely related to solving the technical problems proposed in this application; however, this does not mean that other units do not exist in this embodiment.

[0082] Another embodiment of this application provides an electronic device, such as Figure 7 As shown, it includes a processor 71 and a memory 72. The memory 72 stores instructions that the processor 71 can execute. When the processor 71 is configured to execute the instructions, the electronic device can implement a SAR radar linear frequency modulation signal predistortion compensation method as described in the above method embodiment.

[0083] The memory and processor are connected via a bus, which includes any number of interconnecting buses and bridges, connecting various circuits of one or more processors and the memory. The bus can also connect various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and will not be described further herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be a single component or multiple components, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by the processor is transmitted over the wireless medium via an antenna, which further receives data and transmits it to the processor.

[0084] The processor manages the bus and general processing, and also provides various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory is used to store data used by the processor during operation.

[0085] Another embodiment of this application proposes a computer-readable storage medium storing a computer program that, when executed by a processor, can implement a SAR radar linear frequency modulation signal predistortion compensation method as described in the above method embodiments.

[0086] That is, those skilled in the art will understand that all or part of the steps in the above method embodiments can be implemented by a program instructing related hardware. The program is stored in a storage medium and includes several instructions to cause a device (such as a microcontroller, chip, etc.) or processor to execute all or part of the steps of the method described in the method embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory, random access memory, magnetic disks, or optical disks.

[0087] Those skilled in the art will understand that the above embodiments are specific implementations of this application, and in practical applications, various changes can be made in form and detail without departing from the spirit and scope of this application. For those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

Claims

1. A predistortion compensation device for linear frequency modulated (LFM) signals of SAR radar, characterized in that, The device is an integrated unit comprising: a control module, a microwave module, a data acquisition module, and a calibration and update module; The control module is used to receive control commands and generate drive signals in response to the control commands; wherein the drive signals are used to drive the radio frequency switch. The microwave module, connected to the control module, is used to respond to the drive signal, determine the received radar transmitted signal, and perform channel selection and down-conversion processing on the radar transmitted signal based on the drive signal to output an intermediate frequency signal. The acquisition module, connected to the microwave module, is used for high-speed acquisition of intermediate frequency signals to obtain the frequency-converted waveform data; The calibration and update module, connected to the acquisition module and the control module, is used to process the frequency-converted waveform data into a baseband waveform, compare it with the ideal waveform data, calculate the phase error, and generate pre-distortion correction data based on the phase error to update the radar's transmitted waveform.

2. The apparatus according to claim 1, characterized in that, The control module includes an industrial control unit and a logic control unit; The industrial control unit is used to receive control commands through a human-machine interface; The logic control unit is used to receive macro-control commands and generate drive signals of preset levels to control the microwave module.

3. The apparatus according to claim 1, characterized in that, The microwave module specifically includes: The radio frequency switch unit is used to receive radar transmitted signals under the drive of a drive signal, and automatically select and switch to the target signal channel corresponding to the working frequency band of the radar transmitted signals to obtain radio frequency signals. The mixing and filtering unit is used to mix and down-convert the radio frequency signal and the local oscillator signal, and then filter the signal to output the intermediate frequency signal.

4. The apparatus according to claim 3, characterized in that, The radio frequency switching unit integrates single-pole four-throw electromechanical switches for various radar frequency bands to achieve automatic selection and switching of signal channels.

5. The apparatus according to claim 4, characterized in that, The downconversion module and filter module in the mixing and filtering unit are replaceable components to adapt to different radar frequency bands.

6. The apparatus according to claim 1, characterized in that, The data acquisition module specifically includes: A high-speed analog-to-digital converter is used to acquire and convert intermediate frequency signals at high speed to obtain the digital signal corresponding to the frequency-converted waveform data. The data storage unit is used to store the digital signal corresponding to the waveform data after actual frequency conversion.

7. The apparatus according to claim 6, characterized in that, The device further includes: a data interaction module and a power module; The data interaction module is used to interconnect the various modules in the device through a gigabit network switch to build an internal local area network and realize data interaction between the modules. The power supply module employs a two-stage multi-channel power supply mode combining switching power supplies and linear power supplies to provide stable power to each module while suppressing ripple noise.

8. A method for predistortion compensation of linear frequency modulated (LFM) signals in SAR radar, characterized in that, The method, applied to the apparatus as described in any one of claims 1 to 7, comprises: It receives control commands and generates drive signals in response to the control commands; wherein the drive signals are used to drive the radio frequency switch. In response to the drive signal, the received radar transmitted signal is determined, and the radar transmitted signal is channel selected and down-converted based on the drive signal to output an intermediate frequency signal; The intermediate frequency signal is acquired at high speed to obtain the waveform data after frequency conversion; The frequency-converted waveform data is processed into a baseband waveform and compared with the ideal waveform data to calculate the phase error. Based on the phase error, pre-distortion correction data is generated to update the radar's transmitted waveform.

9. A predistortion compensation device for SAR radar linear frequency modulated signals, characterized in that, The device has an integrated box structure, including a housing and multiple modules integrated inside the housing; the multiple modules include a control module, a microwave module, an acquisition module, and a correction and update module; the device can implement the SAR radar linear frequency modulation signal pre-distortion compensation method as described in claim 8.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it can implement the SAR radar linear frequency modulation signal predistortion compensation method as described in claim 8.

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