介绍了直接数字频率合成器（DDS）成功开发的基础上扩展其频率上限的一些方法，同时对其杂散进行了分析。DDS芯片采用AD9852，控制电路采用TMS320C31，该数字频率合成器通过编程方便地完成调幅、调频和调相功能，经过实际应用达到了比较满意的效果。

Based on the successful development of DDS, some methods to expand its upper frequency limit are described and its spurious analysis is performed in this paper. The DDS chip adopts AD9852 and the control circuit applies TMS320C31. By programming, this DDS can easily achieve amplitude modulation, frequency modulation and phase modulation. The practical application achieves preferable effect.

TN74