Abstract: According to the properties of modern radar signals,the generating schemes of chaotic phasemodulated signals and chaotic bi-phase coded signals on the basis of direct digital synthesis technology(DDS) are presented.With DDS and duplicate correlation method,the chaotic sequence is chosen as a phase control word.Then,the chaotic phase-modulated signals and chaotic bi-phase coded signals are generated.The ambiguity characteristics of the signals are researched by the statistic average of wideband ambiguity functions,and the anti-interference performances are analyzed.The simulation examples show the effectiveness of the proposed approaches.