Direct Digital Linear Fm Signal Generator

At the beginning of this paper, the principle of the radar ALT is introduced, then the general technique to generate the linear FM signal and DDS are discribed. After analyzing the principle of DDS method, a design is introduced in details. Combining the FPGA and traditional DDS method, It is the important improvement on conventional frequency synthesis method. At the end of this paper, the waveforms of output are shown and the analysis of the output and the suggestions for further research are presented.