The Design And Implementation Of Multi-channel Programmable Radar Signal Source

With the increasing intensity of radar countermeasures,traditional radar signal source platforms can no longer meet the various requirements of modern warfare on signal sources.Modern radar countermeasures require that radar signal sources can be programmed to generate various baseband and multi-channel signals.The transmitted signal should also have a good low interception.This thesis aims at these requirements,designed a multi-channel programmable radar signal source system that based on the direct digital waveform synthesis(DDWS)technology.The main research contents of this thesis are as follows:The principle and construction of direct digital frequency synthesis(DDFS)and direct digital waveform synthesis(DDWS)were studied,and the waveform synthesis scheme based on DDWS technology was determined,which laid a solid theoretical foundation for the subsequent waveform synthesis work.The characteristics of LFM pulse signal and two-phase coded pulse signal are studied.Based on the idea of orthogonal frequency division,the orthogonal frequency-divided LFM signal and orthogonal 2-phase coded signal are designed,which laid a foundation for multi-channel output of the signal source.Based on the principle of phase stay,nonlinear frequency-modulated signals were designed using the window function inversion method,and chaotic two-phase encoded signals were designed based on the chaotic principle,which laid a signal basis for low signal interception.Using MATLAB to simulate the designed waveform,the time-domain frequency domain and correlation characteristics of the designed waveform are analyzed.The simulation results showed that the designed waveform satisfies the design requirements.The upper computer software is designed by the mixed programming method of VS and MATLAB.The upper computer provides waveform type and parameter selection function,theoretical waveform simulation display function,system information display function,waveform storage information management function,and Ethernet communication function,which laid the software foundation for the programmability of the signal source.A multi-channel output hardware scheme was designed to lay the hardware foundation for multi-channel signal source performance.FPGA is used as the logic control core of the signal source system.Based on the top-down design method,the FPGA Ethernet receive processing module,FLASH read/write control module and RAM read/write control module were designed and implemented,which laid the hardware foundation for programmability of signal source system.In order to verify whether the designed signal source system meets the design requirements,a system performance test platform based on Xilinx Virtex-5 series development board ML507 was built.Based on this test system,the signal source system was tested.It shows that the function and performance of the radar signal source system can meet the design requirements.