Design And Implementation Of Radar Signal Generator Of Real-time Hopping

With the development of radio technology, the electromagnetic environment hasbecome increasingly complex, especially for the3～30MHz shortwave bands where theHigh-Frequency radar works. The current HFSWR generally works under multiplefrequencies simultaneously. However when one or several frequencies are interfered, itis necessary to change the frequency. When changing the interfered frequencies, theradar system has to be stopped, and the whole process takes a few seconds or longer.This may cause the lost or interruption of the track of targets. How to dodge interferenceand achieve real-time synchronization frequency hopping for radar is the main contentof this paper.The background of this paper is HFSWR and the purpose is to explore the ways ofdesigning and implementing a radar signal generator which can realize real-timefrequency hopping. This paper is divided into three parts.In the first part, the demand of the radar system is analyzed, and the overallprogram of the real-time frequency hopping radar signal generator is designed. Theentire program is divided into three parts which are the interface module, multi-channelmanagement module and multi-channel signal generation module. Then the chipselection and the introduction of function of the three parts are described in detail in thepaper.In the second part, the circuit design of individual modules is done based on theoverall program, including power supply module, clock reset module, DSP module,FPGA module, DUC module and USB module. Then the system schematic and PCB aredesigned using the Altium Designer09. The details of PCB design process and theissues that need attention are introduced too. After printing the circuit board, the paperintroduces the commissioning work of the entire hardware module, including the FPGAchip and its peripheral circuits, DSP chip and its peripheral circuits, USB interfacecircuit and the communication interface circuit between the DSP and FPGA. And thenthe debugging methods and test results are given.In the third part, the design of main software is introduced. Several radar signalwaveforms required in the project are analyzed and simulated using MATLAB. Then ascheme of radar signal baseband data generation based on DSP software is designed. The implementations of system control modules based on Verilog HDL are introducedin the FPGA software section. The design of USB firmware program is introduced inthe USB software section.Finally, the joint debugging and testing on the system are done, and the result ofexpected signals is given. The signal modulated noise and hopping speed are tested. Testresults show that the design of radar signal generator can produce the desired signalwaveforms, and can realize frequency hopping of real-time synchronization, and itsperformance of signal modulated noise and speed of frequency hopping meet theexpectations.