A hardware-in-the-loop simulation system for an airborne monopulse radar

Abstract

This invention discloses a hardware-in-the-loop simulation system for airborne monopulse radar, primarily addressing the problem that existing technologies cannot simulate the entire process of airborne monopulse radar signal processing from the antenna front-end to the back-end. It includes an echo simulation module, a receiving module, and a signal processing module. The echo simulation module simulates and generates radio frequency (RF) echo signals from the sum, pitch difference, and azimuth difference channels of the monopulse radar during aircraft flight. The receiving module down-converts these three RF echo signals to obtain three intermediate frequency (IF) signals. The signal processing module samples and processes these three IF signals, outputting the target detection range, velocity, pitch angle, and azimuth angle of the aircraft. This invention uses a combination of hardware and software to design an airborne monopulse radar simulation system, resulting in a short development cycle, low cost, high reusability, and the ability to simulate the entire process of airborne monopulse radar signal processing from the antenna front-end to the back-end. It can be used for the design and functional verification of airborne monopulse radar.

Description

Technical Field

[0001] This invention belongs to the field of radar technology, and specifically relates to a hardware-in-the-loop simulation system that can be used for the design and functional verification of airborne monopulse radar. Background Technology

[0002] During the research and development and production of radar, it is necessary to test the radar's performance and specifications. Traditional testing methods rely on field trials, which use real targets to provide echo signals to the radar. This requires significant manpower, material resources, and financial investment, lengthening the development cycle. This is especially true for airborne products, which require flight tests to verify functional performance. Testing radar performance indicators through field trials results in long development cycles and high development costs.

[0003] Simulation techniques combining hardware and software can simulate targets and usage scenarios to provide echo signals for airborne monopulse radars. Radar hardware-in-the-loop simulation systems can shorten radar development cycles and reduce development costs, offering advantages such as economy, flexibility, and reusability. During the development phase, the simulation system can validate various radar performance indicators and simulate problems encountered in actual radar use. During the production and delivery phase, it can also provide an evaluation tool for testing radar system performance.

[0004] Simulation can be used to simulate radar echo signals under different aircraft attitudes, altitudes, and speeds, in order to verify the design of radar waveforms, antenna patterns, and radar signal processing algorithms.

[0005] Patent application CN107436755A discloses a "Modeling Method and System for Radar Simulation Systems," whose main purpose is to provide a modeling method for radar simulation systems, simulating and reproducing the working mechanism and process of radar in different scenarios on a computer. This system is a software-level simulation, which can perform theoretical simulation verification during the radar design phase. However, in the actual testing and production phases of radar, it is necessary to test the hardware specifications of radar subsystems and their external hardware interface relationships. Therefore, this purely software simulation system cannot be used in the testing and production delivery phases of radar, resulting in limitations in its application. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of the prior art by proposing a hardware-in-the-loop simulation system for airborne monopulse radar, in order to verify and evaluate the overall functional performance of airborne monopulse radar and meet the usage requirements of the radar design, testing, and production delivery stages.

[0007] The technical solutions for achieving the objectives of this invention include the following.

[0008] 1. A hardware-in-the-loop simulation system for an airborne monopulse radar, characterized in that it includes a simulation module 1, a receiving module 2, and a signal processing module 3, wherein the receiving module 2 is unidirectionally connected to the monopulse radar echo simulation module 1 and the signal processing module 3 respectively;

[0009] The echo simulation module 1 includes a baseband echo submodule 11 and an echo simulation submodule 12. The baseband echo submodule is used to generate a baseband echo signal with target characteristics and aircraft flight attitude. The echo simulation submodule is used to upconvert the baseband echo signal and transmit the upconverted radio frequency signal to the receiving module 2.

[0010] The receiving module 2 is used to transmit the intermediate frequency signal after down-conversion of the radio frequency signal to the signal processing module 3; it includes a channel 21, an elevation difference channel 22, an azimuth difference channel 23, a control submodule 24, a frequency source 25, and a power supply submodule 26; each of the three channels is equipped with a digitally controlled attenuator, and its attenuation is controlled by the control submodule; the frequency source generates the high local oscillator and low local oscillator signals required for down-conversion of the three channels, as well as the synchronization signal of the echo simulation module and the clock signal of the signal processing module;

[0011] The signal processing module 3 includes an ADC submodule 31, a signal processing submodule 32, a storage submodule 33, and a power supply submodule 34. The ADC submodule samples the intermediate frequency signal and transmits the sampled signal to the signal processing submodule. The signal processing submodule performs signal processing on the sampled signal. The storage submodule is used to store the data of the signal processing submodule and load the chip program.

[0012] Furthermore, the baseband echo submodule 11 includes a parameter setting unit 111, a transmitting unit 112, an antenna unit 113, a target RCS unit 114, a clutter signal unit 115, and a baseband echo generation unit 116.

[0013] The parameter setting unit 111 is used to set the basic parameters of the carrier aircraft, including the carrier aircraft's flight altitude, three-axis velocity and attitude information, and transmit them to the baseband echo generation unit.

[0014] The transmitting unit 112 is used to configure the transmission signal frequency, power, pulse width, pulse period and modulation method, and transmit them to the baseband echo generation unit;

[0015] The antenna element 113 is used to generate antenna patterns for the azimuth channel, azimuth difference channel, and elevation difference channel, and transmit them to the baseband echo generation unit.

[0016] The target RCS unit 114 is used to set the number of targets and RCS characteristics, and transmits them to the baseband echo generation unit.

[0017] The clutter signal unit 115 is used to set the clutter signal model and clutter power, and transmit them to the baseband echo generation unit.

[0018] The baseband echo generation unit 116 is used to generate baseband echo data for the azimuth, pitch, and azimuth channels.

[0019] Furthermore, the echo simulation submodule 12 includes a signal storage unit 121, an analog signal generation unit 122, and an up-conversion unit 123;

[0020] The signal storage unit 121 is used to store the generated baseband echo data;

[0021] The analog signal generation unit 122 is used to convert the stored baseband echo data into an analog signal and output it to the upconversion unit;

[0022] The upconversion unit 123 is used to upconvert the generated analog signal to the radio frequency band.

[0023] Furthermore, the control submodule 24 includes a communication unit 241 and a control unit 242;

[0024] The communication unit 241 is used to receive control information from the signal processing module and transmit the received information to the control unit.

[0025] The control unit 242 is used to transmit control signals to the three-channel digitally controlled attenuator.

[0026] Furthermore, the ADC submodule 31 includes a channel unit 311, an azimuth difference channel unit 312, and a pitch difference channel unit 313;

[0027] The channel unit 311 is used to perform ADC sampling on the intermediate frequency signal of the channel and transmit the sampled signal to the signal processing submodule.

[0028] The pitch difference channel unit 312 is used to perform ADC sampling on the pitch difference channel intermediate frequency signal and transmit the sampled signal to the signal processing submodule.

[0029] The azimuth difference channel unit 313 is used to perform ADC sampling on the intermediate frequency signal of the azimuth difference channel and transmit the sampled signal to the signal processing submodule.

[0030] Furthermore, the signal processing submodule 32 includes a signal processing unit 321, a data processing unit 322, and a communication unit 323;

[0031] The signal processing unit 321 is used to implement radar signal processing algorithms and transmit the processed data to the data processing unit.

[0032] The data processing unit 322 is used to implement radar data processing related algorithms;

[0033] The communication unit 323 is used to communicate with the receiving module and output the simulation results of the system.

[0034] 2. A method for simulating airborne monopulse radar using the above system, characterized by the following implementation:

[0035] In the baseband echo submodule 11 of the radar echo simulation module 1, initial parameters are set to simulate and generate three baseband echo data of the single pulse radar during aircraft flight: the sum channel, the pitch difference channel, and the azimuth difference channel.

[0036] The three baseband echo data are transmitted to the echo simulation submodule 12 to generate radio frequency echo signals, which are then output to the receiving module 2.

[0037] The receiving module 2 performs down-conversion processing on the three radio frequency echo signals to obtain three intermediate frequency signals, and transmits them to the signal processing module 3;

[0038] The signal processing module 3 samples and processes the three intermediate frequency signals sequentially through its ADC submodule 31 and signal processing submodule 32, and outputs the target detection range, speed, pitch angle and azimuth angle of the carrier aircraft, realizing the full-process simulation of the airborne monopulse radar from the front end of the antenna to the back end of the signal processing.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] First, because the present invention has different functional units in the echo simulation module 1, it can perform different functions. Specifically, the parameter setting unit 111 simulates the flight altitude, speed, attitude information and flight status of the carrier aircraft; the transmitting unit 112 performs simulation verification of the radar transmitter; the antenna unit 113 performs simulation verification of the radar antenna pattern; and the target RCS unit 114 simulates the RCS characteristics and number of targets. This not only reduces the design and verification workload of the radar transmitter and antenna and shortens the development cycle, but also reduces the time and cost of flight tests and field tests by simulating the flight status of the carrier aircraft and the detection of targets.

[0041] Secondly, since the present invention is equipped with a receiving module 2, the three radio frequency echo signals generated by the echo simulation module 1 are down-converted to the intermediate frequency band and then transmitted to the signal processing module 3 for processing. This processing flow of the radar receiver is realized through hardware circuitry, which can simulate the radar receiver system and assist in completing the antenna and transmitter testing work in the production stage, thereby reducing testing costs.

[0042] Third, the present invention processes the received three intermediate frequency signals through the signal processing module 3, which can not only complete the algorithm verification and hardware design evaluation of the radar signal processing platform, but also assist in the testing of the receiver during the production stage. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the present invention;

[0044] Figure 2 This is a schematic diagram of the echo simulation module in this invention;

[0045] Figure 3 This is a schematic diagram of the receiving module in this invention;

[0046] Figure 4 This is a schematic diagram of the signal processing module in this invention;

[0047] Figure 5 This is a simulation flowchart of the present invention; Detailed Implementation

[0048] The present invention will now be described in detail with reference to the accompanying drawings.

[0049] Reference Figure 1 This invention includes a single-pulse radar echo simulation module 1, a receiving module 2, and a signal processing module 3. The receiving module 2 is unidirectionally connected to both the echo simulation module 1 and the signal processing module 3. The echo simulation module 1 generates three radio frequency echo signals (sum, azimuth, and elevation) at a carrier frequency of 16.5 GHz, which are transmitted to the receiving module 2. The receiving module 2 performs secondary down-conversion processing on the three channels (sum, elevation, and azimuth) to down-convert the radio frequency echoes to the intermediate frequency band. These signals are then sent to the signal processing module 3 for ADC sampling and signal processing to obtain the target's range, velocity, elevation angle, azimuth angle, and AGC control information.

[0050] refer to Figure 2 The echo simulation module 1 includes a baseband echo submodule 11 and an echo simulation submodule 12. The baseband echo submodule 11 includes a parameter setting unit 111, a transmitting unit 112, an antenna unit 113, a target RCS unit 114, a clutter signal unit 115, and a baseband echo generation unit 116. The echo simulation submodule 12 includes a signal storage unit 121, an analog signal generation unit 122, and an up-conversion unit 123.

[0051] The parameter setting unit 111 is used to set the basic parameters of the carrier aircraft, including the carrier aircraft's flight altitude, three-axis velocity and attitude information, and transmit the parameter information to the baseband echo generation unit 116;

[0052] The transmitting unit 112 is used to configure the transmitting signal frequency, power, pulse width, pulse period and modulation method, and transmit the parameter information to the baseband echo generation unit 116;

[0053] The antenna element 113 is used to generate antenna patterns for the azimuth channel, azimuth difference channel, and elevation difference channel, and transmits the parameter information to the baseband echo generation unit 116.

[0054] The target RCS unit 114 is used to set the number of targets and RCS characteristics, and transmits the parameter information to the baseband echo generation unit 116;

[0055] The clutter signal unit 115 is used to set the clutter signal model and clutter power, and transmit the parameter information to the baseband echo generation unit 116;

[0056] The baseband echo generation unit 116 is used to generate baseband echo data for the azimuth, pitch, and azimuth channels.

[0057] The signal storage unit 121 is used to store the generated baseband echo signal data;

[0058] The analog signal generation unit 122 is used to convert the stored baseband echo data into an analog signal and output it to the up-conversion unit 123;

[0059] The upconversion unit 123 is used to upconvert the generated analog signal to the radio frequency band.

[0060] In this example, the parameters set for each unit and module of echo simulation module 1 are, but are not limited to, the following:

[0061] In parameter setting unit 111, the aircraft flight altitude is set to 500m, the X-axis speed is 20km / h, the Y-axis speed and Z-axis speed are 0km / h, the aircraft pitch angle is set to 0°, and the roll angle is set to 0°.

[0062] The transmitting unit 112 has a transmitting signal frequency of 16.5 GHz, a transmitting power of 150 W, a pulse width of 10 μs, and a pulse period of 100 μs.

[0063] Antenna element 113 is configured with four antenna beams, with a gain of 25dB, a beamwidth of 5°, and a deviation angle of 2° between each beam. These four antenna beams are used to generate the radar's sum antenna pattern, azimuth difference antenna pattern, and elevation difference antenna pattern.

[0064] In target RCS unit 114, the target is set to a car, with a quantity of 1 and an RCS of 100m. 2 ;

[0065] The clutter signal model in clutter signal unit 115 is set to Rayleigh type;

[0066] The baseband echo generation unit 116 generates baseband echo data for the azimuth channel, azimuth difference channel, and elevation difference channel according to the above-mentioned set parameters.

[0067] The signal storage unit 121 is implemented using a high-capacity DDR chip, and the analog signal generation unit 122 uses an FPGA and a DAC chip to read the baseband echo signal data in the signal storage unit and convert it into an analog signal for output to the upconversion unit 123. In the upconversion unit 123, the analog signal is upconverted to 16.5GHz and output through three SMA RF interfaces.

[0068] refer to Figure 3 The receiving module 2 includes a channel 21, an elevation difference channel 22, an azimuth difference channel 23, a control submodule 24, a frequency source 25, and a power supply submodule 26; wherein the control submodule 24 includes a communication unit 241 and a control unit 242.

[0069] The three channels, namely channel 21, pitch difference channel 22, and azimuth difference channel 23, are used to down-convert the RF echo signal to the intermediate frequency band. After the RF echo signal enters these three channels, it first passes through a low-noise amplifier (LNA) and a filter; then it undergoes a first down-conversion with a mixer and a high local oscillator signal; then it is amplified by an amplifier, and then undergoes a second down-conversion with a mixer and a low local oscillator signal; after passing through a filter and a digitally controlled attenuator, it is amplified by an amplifier and filtered again before outputting the intermediate frequency signals of the three channels.

[0070] The frequency source 25 is used to generate the high local oscillator and low local oscillator signals required for the three-channel downconversion, as well as the synchronization signal of the echo simulation module 1 and the clock signal of the signal processing module 3.

[0071] The communication unit 241 is used to receive control information from the signal processing module 3 and transmit the received information to the control unit 242.

[0072] The control unit 242 is used to transmit control signals to the three-channel digitally controlled attenuator.

[0073] In this example, the receiving module 2 has 8 signal interfaces and 1 control interface; 3 RF signal SMA input ports for receiving the three channels of RF echo signals generated by the echo simulation module; the module has 5 signal output interfaces, including 3 intermediate frequency signal SMA output interfaces, 1 clock signal SMA output interface, and 1 synchronization signal SMA output interface; the control interface is a 15-pin micro rectangular socket, which is connected to the signal processing module 3;

[0074] Channels 21, 22, and 23 first pass the RF signal through a low-noise amplifier (LNA) and a filter, then mix it with a 1.6GHz high local oscillator signal via a mixer for the first down-conversion process, reducing the 16.5GHz±fd signal to 1.6GHz±fd. Next, the signal passes through an amplifier, then through another mixer with a 150MHz low local oscillator signal for the second down-conversion process, reducing the 1.6GHz±fd signal to 150MHz±fd. Finally, the signal passes through a filter and a digitally controlled attenuator, then through another amplifier and filter before being output to signal processing module 3.

[0075] The communication unit 241 of the control submodule 24 uses an RS422 interface chip for communication, receives the AGC control signal transmitted by the signal processing module 3, and transmits it to the control unit 242; the control unit 242 uses an FPGA chip to solve the control signal and sends it to the digitally controlled attenuators in the three channels; the control submodule 24 is connected to the signal processing module 3 through the control interface, and the communication method is RS422 serial port.

[0076] Frequency source 25 provides stable high local oscillator and low local oscillator signals to three channels, and outputs synchronization signal and clock signal at the same time; the high local oscillator signal frequency is 1.6GHz, the low local oscillator signal frequency is 150MHz, the generated synchronization signal is 10MHz and output to echo simulation module 1, and the generated clock signal frequency is 120MHz and output to signal processing module 3.

[0077] The power supply submodule 26 converts the 220V AC voltage into ±12V DC voltage suitable for the module.

[0078] refer to Figure 4 The signal processing module 3 includes an ADC submodule 31, a signal processing submodule 32, a storage submodule 33, and a power supply submodule 34. The ADC submodule 31 includes a pitch difference channel unit 311, an elevation difference channel unit 312, and an azimuth difference channel unit 313; the signal processing submodule 32 includes a signal processing unit 321, a data processing unit 322, and a communication unit 323.

[0079] The channel unit 311 is used to perform ADC sampling on the intermediate frequency signal of the channel and transmit the sampled signal to the signal processing submodule 32;

[0080] The pitch difference channel unit 312 is used to perform ADC sampling on the pitch difference channel intermediate frequency signal and transmit the sampled signal to the signal processing submodule 32.

[0081] The azimuth difference channel unit 313 is used to perform ADC sampling on the intermediate frequency signal of the azimuth difference channel and transmit the sampled signal to the signal processing submodule 32.

[0082] The signal processing unit 321 is used to implement radar signal processing algorithms and transmit the processed data to the data processing unit 322.

[0083] The data processing unit 322 is used to implement radar data processing related algorithms;

[0084] The communication unit 323 is used to communicate with the receiving module 2 and output the simulation results of the system.

[0085] The storage submodule 33 is used to store data from the signal processing submodule 32 and load chip programs.

[0086] In this example, signal processing module 3 is equipped with 4 SMA interfaces, 3 intermediate frequency SMA input interfaces, and 1 clock signal SMA input interface;

[0087] The ADC submodule 31 performs AD sampling on the intermediate frequency signals of the three channels in the pitch difference channel unit 311, the elevation difference channel unit 312, and the azimuth difference channel unit 313 through three SMA input interfaces. The sampling frequency is 500MHz, and then the sampled signals are transmitted to the signal processing submodule.

[0088] The signal processing unit 321 of the signal processing submodule 32 uses, but is not limited to, a Xilinx XCVX690T FPGA chip. In this unit, the received sampled signal is filtered and pulse compressed, and the processed signal is transmitted to the data processing unit 322. The data processing unit 322 uses, but is not limited to, a TI TMS320C6678 multi-core DSP chip. In this unit, the moving target indication (MTI), moving target detection (MTD), constant false alarm rate (CFAR), deambiguity, amplitude comparison, angle measurement, and AGC control detection processing of the monopulse radar are implemented, obtaining the corresponding processed target range, velocity, elevation angle, azimuth angle, and AGC control information, which is then transmitted to the communication unit 323. The communication unit 323 transmits the AGC control information to the receiving module 2 and outputs the target's range, velocity, elevation angle, and azimuth angle information. The communication unit 323 uses an RS422 interface chip for communication.

[0089] The storage submodule 33 uses, but is not limited to, FLASH memory chips to store data and load programs; the power supply submodule 34 converts the 220V AC voltage into ±24V DC voltage suitable for the module.

[0090] Reference Figure 5 The method for simulating airborne monopulse radar using the above system is as follows:

[0091] S1, set initial parameters in the baseband echo submodule 11 of the radar echo simulation module 1 to simulate and generate three baseband echo data of the single pulse radar during aircraft flight: the sum channel, the pitch difference channel, and the azimuth difference channel.

[0092] S2, transmits the three baseband echo data to the echo simulation submodule 12 to generate radio frequency echo signals and outputs them to the receiving module 2;

[0093] S3, the receiving module 2 performs down-conversion processing on the three radio frequency echo signals to obtain three intermediate frequency signals, and transmits them to the signal processing module 3;

[0094] S4, Signal processing module 3 sequentially samples and processes the three intermediate frequency signals through its ADC submodule 31 and signal processing submodule 32:

[0095] S41) ADC submodule 31 samples the three intermediate frequency signals and transmits the sampled signals to signal processing unit 321 in signal processing submodule 32;

[0096] S42) Signal processing unit 321 performs filtering and pulse compression processing on the three sampled signals and transmits the processed three signals to data processing unit 322;

[0097] S43) Data processing unit 322 performs the following two processes on the three sampled signals simultaneously:

[0098] The first method involves processing the three sampling signals with Moving Target Indication (MTI) and Moving Target Detection (MTD) first, then simultaneously performing Constant False Alarm Rate (CFAR) detection and de-ambiguity processing on the processed signals, and then performing single-pulse amplitude comparison angle measurement processing with the pitch difference channel and azimuth difference channel signals respectively to obtain the corresponding processed target distance, velocity, pitch angle and azimuth angle, and transmitting them to the communication unit 323.

[0099] The second method involves automatically gain control (AGC) detection of the amplitude of the three sampled signals to obtain AGC control information, which is then transmitted to the communication unit 323.

[0100] S5, the communication unit 323 transmits AGC control information to the receiving module 2 and outputs the target's range, speed, elevation angle and azimuth angle information, realizing the full-process simulation of airborne monopulse radar from the antenna front end to the back end signal processing.

[0101] The above description is merely a specific example of the present invention and does not constitute any limitation on the present invention. Obviously, those skilled in the art, after understanding the content and principles of the present invention, may make various modifications and changes in form and details without departing from the principles and structure of the present invention. However, these modifications and changes based on the ideas of the present invention are still within the scope of protection of the claims of the present invention.

Claims

1. A hardware-in-the-loop simulation system for an airborne monopulse radar, characterized in that, Including echo simulation The module consists of a receiving module (1), a receiving module (2), and a signal processing module (3). The receiving module (2) is unidirectionally connected to the single-pulse radar echo simulation module (1) and the signal processing module (3), respectively. The echo simulation module (1) includes a baseband echo submodule (11) and an echo simulation submodule (12). The baseband echo submodule is used to generate a baseband echo signal with target characteristics and aircraft flight attitude. The echo simulation submodule is used to upconvert the baseband echo signal and transmit the upconverted radio frequency signal to the receiving module (2). The receiving module (2) is used to transmit the intermediate frequency signal after downconversion of the radio frequency signal to the signal processing module (3); it includes a channel (21), an elevation difference channel (22), an azimuth difference channel (23), a control submodule (24), a frequency source (25), and a power supply submodule (26); each of the three channels is equipped with a digitally controlled attenuator, and its attenuation is controlled by the control submodule; the frequency source generates the high local oscillator and low local oscillator signals required for downconversion of the three channels, as well as the synchronization signal of the echo simulation module and the clock signal of the signal processing module; The signal processing module (3) includes an ADC submodule (31), a signal processing submodule (32), a storage submodule (33), and a power supply submodule (34). The ADC submodule samples the intermediate frequency signal and transmits the sampled signal to the signal processing submodule. The signal processing submodule performs signal processing on the sampled signal. The storage submodule is used to store the data of the signal processing submodule and load the chip program.

2. The system according to claim 1, characterized in that, The baseband echo submodule (11) includes a parameter setting unit (111), a transmitting unit (112), an antenna unit (113), a target RCS unit (114), a clutter signal unit (115), and a baseband echo generation unit (116). The parameter setting unit (111) is used to set the basic parameters of the carrier aircraft, including the carrier aircraft's flight altitude, three-axis velocity and attitude information, and transmit them to the baseband echo generation unit; The transmitting unit (112) is used to configure the transmission signal frequency, power, pulse width, pulse period and modulation method, and transmit them to the baseband echo generation unit; The antenna element (113) is used to generate antenna patterns for the azimuth channel, azimuth difference channel, and elevation difference channel, and transmit them to the baseband echo generation unit; The target RCS unit (114) is used to set the number of targets and RCS characteristics, and transmits them to the baseband echo generation unit; The clutter signal unit (115) is used to set the clutter signal model and clutter power, and transmit them to the baseband echo generation unit; The baseband echo generation unit (116) is used to generate baseband echo data for the azimuth, pitch, and azimuth channels.

3. The system according to claim 1, characterized in that, The echo simulation submodule (12) includes a signal storage unit (121), an analog signal generation unit (122), and an up-conversion unit (123). The signal storage unit (121) is used to store the generated baseband echo data; The analog signal generation unit (122) is used to convert the stored baseband echo data into an analog signal and output it to the upconversion unit; The upconversion unit (123) is used to upconvert the generated analog signal to the radio frequency band.

4. The system according to claim 1, characterized in that, The control submodule (24) includes a communication unit (241) and a control unit (242). The communication unit (241) is used to receive control information from the signal processing module and transmit the received information to the control unit. The control unit (242) is used to transmit control signals to the three-channel digitally controlled attenuator.

5. The system according to claim 1, characterized in that, The ADC submodule (31) includes a channel unit (311), a pitch difference channel unit (312), and an azimuth difference channel unit (313). The channel unit (311) is used to perform ADC sampling on the intermediate frequency signal of the channel and transmit the sampled signal to the signal processing submodule; The pitch difference channel unit (312) is used to perform ADC sampling on the intermediate frequency signal of the pitch difference channel and transmit the sampled signal to the signal processing submodule. The azimuth difference channel unit (313) is used to perform ADC sampling on the intermediate frequency signal of the azimuth difference channel and transmit the sampled signal to the signal processing submodule.

6. The system according to claim 1, characterized in that, The signal processing submodule (32) includes a signal processing unit (321), a data processing unit (322), and a communication unit (323). The signal processing unit (321) is used to implement radar signal processing related algorithms and transmit the processed data to the data processing unit; The data processing unit (322) is used to implement radar data processing related algorithms; The communication unit (323) is used to communicate with the receiving module and output the simulation results of the system.

7. A method for simulating airborne monopulse radar using the system described in claim 1, characterized in that, The implementation is as follows: In the baseband echo submodule (11) of the radar echo simulation module (1), initial parameters are set to simulate and generate three baseband echo data of the single pulse radar during aircraft flight: the sum channel, the pitch difference channel, and the azimuth difference channel. The three baseband echo data are transmitted to the echo simulation submodule (12) to generate radio frequency echo signals and output to the receiving module (2). The receiving module (2) performs down-conversion processing on the three radio frequency echo signals to obtain three intermediate frequency signals, and transmits them to the signal processing module (3). The signal processing module (3) samples and processes the three intermediate frequency signals sequentially through its ADC submodule (31) and signal processing submodule (32), and outputs the target range, speed, pitch angle and azimuth angle of the carrier aircraft, realizing the full-process simulation of the airborne monopulse radar from the front end of the antenna to the back end of the signal processing.

8. The method according to claim 7, characterized in that, The ADC submodule (31) and signal processing submodule (32) sequentially sample and process the three intermediate frequency signals as follows: The ADC submodule (31) samples the three intermediate frequency signals and transmits the sampled signals to the signal processing unit (321) in the signal processing submodule (32). The signal processing unit (321) performs filtering and pulse compression on the three sampled signals and transmits the processed three signals to the data processing unit (322). The data processing unit (322) performs the following two processes on the three sampled signals simultaneously: The first method involves processing the three sampling signals with Moving Target Indication (MTI) and Moving Target Detection (MTD), then simultaneously performing Constant False Alarm Rate (CFAR) detection and defuzzification on the processed signals, and then performing single-pulse amplitude comparison angle measurement with the pitch difference channel and azimuth difference channel signals respectively, to obtain the corresponding processed target distance, velocity, pitch angle and azimuth angle, and transmitting them to the communication unit (323). The second method involves automatically gain control (AGC) detection of the amplitude of the three sampled signals to obtain AGC control information, which is then transmitted to the communication unit (323). The communication unit (323) transmits AGC control information to the receiving module (2) and outputs the distance, speed, pitch angle and azimuth angle information of the detected target.

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