Shaped Signal Based On The Dds Leidaduobo

Advanced radar systems not only search, detect, capture and track targets, but also gather detailed information from the targets. There is an increasing demand for multidimensional high resolution, especially in multi-targets environment. Large time-band product signals such as linear frequency modulation signals (LFM), nonlinear frequency modulation signals (NLFM), phase coded signals and so on are one of key technologies for pulse compression radar systems. Generating LFM/NLFM signals whose intermediate frequency is 28MHz and bandwidth is 3MHz and 5MHz and time width is from 6us to 300us based on DDS has been discussed in this dissertation. The conclusion is that the wave quality of LFM signal generating through DDS is satisfactory and that of NLFM is not perfect. The primary work in this dissertation:(1) The principle, design and implementation of generating LFM/NLFM signals based on direct digital synthesis (DDS) technology have been discussed Especially, the system has been implemented all by author.(2) This dissertation gives a full analysis of the LFMNLFM signals generation based on DDS technology and some conclusions are also presented.Besides, this dissertation summarizes development of radar technology, introduces the radar signal basic theory and discusses the design of LFM/NLFM signals.