Airborne Phased Array Radars Simulator System Design And Realization Research

Airborne radar signal simulator is a result of digital simulation technique combining with radar technique. It produce simulating radar reflected signal, which making it possible to test the airborne radar system on the ground. Because of the important use of radar signal simulator in radar testing, performance evaluating, equipment maintenance and so on, the technique of radar signal simulation has being developed and it has been a important part of radar technique.This dissertation discusses mainly the realization of the radar signal simulator for an Airborne Phased-Array Radar (APAR), the simulation methods of target echo and clutter for APAR, and the application of hi-speed DSP chip in radar simulator.The main content and creative work in this dissertation are as follow:① As part of a research project in national "ninth five-year plan" and "tenth five-year plan", we designed a set of APAR simulator which fulfill the technology requirements and could real-time provide desired radar digital, video frequency and radio frequency echo signal for the target that can be any velocity, any trace, any Swerling type and many kind of radar wave form, PRF and pulse width. From the radio array antenna and control system of the radar simulator, the real target echo signal in the air can be obtain. So, receiving it by radar antenna, actual radar woke state is simulated. The set of APAR simulator meets the demand of APAR system research and development on ground. It is the first APAR simulator that can simulate the multi-target environment of APAR in real-time and can be used in many sides.② The application of Texas Instrument (TI) company new generation hi-speed DSP TMS320C6x is described in the dissertation. The software of DSP is developed in C and assembly language. Because the frame of software is setin C language and the program, which is frequently executed or has speed demand, is compiled in assembly language that has high ability of run in parallel. Therefore the software of DSP not only has very high running speed which can meet the simulator's real-time demand but also has modularization structure and reuse ability.③ A procedure of analyzing terrain clutter spectrum in sum and difference channels for APAR is described in the dissertation. The quantity computed is the expected clutter power at the output of any specified range gate by the method of integrating reflected energy between constant Doppler loci in range-gate circles with a model of sum and difference antenna gain pattern for APAR. Base on the analyzing of APAR terrain clutter spectrum, Rayleigh, Correlated Log-Normal and Weibull distribution terrain clutter of APAR general pulse signal was simulated with the method of zero memory nolinearity transform. ④ The Doppler frequency of target echo is simulated on video frequency in this dissertation. Although there are some tiny difference between the Doppler frequency get by this way and by the way of DDS, in spectrum analyzing, the difference is only on phase and the amplitude of the target get by two ways are same, so the Doppler frequency get by two ways are same too. Therefore this way is feasible, and the system is simplified.⑤ A procedure of analyzing in target echo theory and simulation for APAR is described in the dissertation. In APAR simulator system design scheme a new design is used to generate all the sum, azimuth difference and elevation difference channel target echo signal by passing only one channel signal of target through antenna gain multiplication circuit, which simplified the simulator design.