本设计基于数字频率合成技术,采用正弦查找表实现波形产生.直接数字频率合成技术（DDS）是一种先进的电路结构，能在全数字下对输出信号频率进行精确而快速的控制，DDS技术还在解决输出信号频率增量选择方面具有很好的应用，DDS所产生的信号具有频率分辨率高、频率切换速度快、频率切换时相位连续、输出相位噪声低和可以产生任意波形等诸多优点。

文中介绍了DDS的基本原理，对DDS的质谱及其散杂抑制进行了分析。程序设计采用超高速硬件描述语言VHDL描述DDS,在此基础上设计了正弦波、三角波、方波等信号发生器，。完成了软件和硬件的设计，以及实验样机的部分调试。

-The design is based on a digital frequency synthesis technology, to achieve wave synthesis by sine wave look-up tables. Direct Digital Synthesis Technology (DDS) is an advanced circuit structure, the output signal frequency is controlled precisely and rapidly in all-digital process, DDS technology has been applied in output signal frequency increment. DDS signals generated own high frequency resolution, frequency switching speed and continuous phase when frequency switching, low-output phase noise and can generate arbitrary waveform, and so on.

　　Basic principles of the DDS is introduced in the paper, frequency form and stray inhabitation of the DDS is analyzed. Procedures designed with high-speed hardware descr iption language VHDL describe DDS, and design a sine wave, triangle wave, square-wave signal generator by it.The hardware and software has been designed, prototype and circuit has been tested partly.