基于DDS技术的信号发生器的设计与实现_毕业设计.doc

唐 山 学 院 毕 业 设 计 设计题目：基于DDS技术的信号发生器的设计与实现 2012年6月10 日基于DDS技术的信号发生器的设计与实现 DDS是直接数字式频率合成器（Direct Digital Synthesizer）的英文缩写。与传统的频率合成器相比，DDS具有低成本、低功耗、高分辨率和快速转换时间等优点，广泛使用在电信与电子仪器领域，是实现设备全数字化的一个关键技术。 本设计采用单片机为核心处理器，利用键盘输入信号的参数，控制DDS的AD9850模块产生信号，信号的参数在LCD1602上显示，完成正弦信号和方波信号的输出，用示波器输出验证。 DDS是一种全数字化的频率合成器，由相位累加器、波形ROM、D/A转换器和低通滤波器构成。时钟频率给定后，输出信号的频率取决于频率控制字，频率分辨率取决于累加器位数，相位分辨率取决于ROM的地址线位数，幅度量化噪声取决于ROM的数据位字长和D/A转换器位数。与传统的频率合成方法相比，DDS合成信号具有频率切换时间短、频率分辨率高、相位变化连续等诸多优点。使用单片机灵活的控制能力与AD9850的高性能、高集成度相结合，可以克服传统DDS设计中的不足，从而设计开发出性能优良的信号发生器系统。 关键词：单片机 直接数字频率合成 AD9850 DDS Design and Implementation of the Signal Generator Based on DDS Technology Abstract DDS is Direct Digital frequency Synthesizer (Direct Digital Synthesizer) English abbreviations. Compared with the traditional frequency synthesizer, with low cost, DDS low power consumption, high resolution and fast converting speed time and so on, widely used in telecommunications and electronic instruments field, is to realize equipment full digital a key technology. This design uses the single chip processor as the core, using a keyboard input signal parameters, control of DDS AD9850 module produce signals, the signal parameters in LCD1602 show that the complete sine signal and square wave signal output, the output with an oscilloscope validation. DDS is A full digital frequency synthesizer, by phase accumulators, waveform ROM, D/A converter and low pass filter composition. The clock frequency after A given, the output depends on the frequency of the signal frequency control word, the frequency resolution depends on accumulators digits, phase resolution depends on the ROM address line digits, amplitude quantization noise depends on the ROM data A word length and D/A converter digits. And the frequency of the traditional method than the synthesis, DDS synthesis signal has a frequency switching frequency of short time, high resolution and continuous phase changes, and many other advantages. Using single chip microcomputer contro