Development Of Lfmcw Radar Waveform Generator

With the development of modern digital technology and VLSI, the method of digital waveform synthesis is widely used in radar systems now. The waveform generation using digital system is of strict coherence, repetitiveness, high stability and programmable capability, which can also easily realize the waveform parameter's agility and generate arbitrary complicated waveforms in order to meet the urgent requirement for anti-interference and strong survival ability of radars under modern EW environments. Thus, further researches on digital waveform generation are of much importance recently.According to project request, an experiment waveform generation of a radar system has implement by Direct Digital Synthesis (DDS) and Field Programmable Gate Array (FPGA) technologies, which can generate variable waveforms and modes. The experiment waveform generation can generate 30 MHz Continuous Wave (CW), Linear Frequency Modulation Continuous Wave (LFMCW) with 10 MHz bandwidth working at 30MHz carrier, simulated echo of object which is delayed LFMCW signal. The test results completely meet the system requirements.The primary work in this dissertation:Analyzed the distribution rule of spurious in DDS and some methods to reduce the spurious;Analyzed the linear degree of LFM signal based on DDS technology;Accomplished the design to generate LFM signal and simulated echo of object simultaneity for radar systems;Accomplished the design by FPGA and DDS technologies;Accomplished the debug with center control device, measured fully and analyzed effectively CW, LFMCW and simulated echo of object signals based on DDS technology, achieved satisfying results;Measured and analyzed the beat signal of LFMCW and simulated echo of object signals by sampling, computer processing, achieved satisfying result.