毕业论文设计函数信号发生器的设计与实现.doc

摘 要 信号发生器是科研、教学实验及各种电子测量技术中很重要的一种信号源，随着科学技术的迅速发展，对信号源的要求也越来越高，要求信号源的频率稳定度、准确度及分辨率要高、以适应各种高精度的测量，为了满足这种高的要求，各国都在研制一些频率合成信号源，这种信号源一般都是由一个高稳定度和高准确度的标准参考频率源，采用锁相技术产生千百万个具有同一稳定度和准确度的频率信号源，为了达到高的分辨率往往要采用多个锁相环和小数分频技术，因此使电路复杂、设备体积圈套、成本较高，传统的频率合成器由于采用倍频、分频、混频和滤波环节，使频率合成技术（DDS），与传统的频率合成技术相比，DDS具有频率分辨率高、频率转变速度快、输出相位连续、相位噪声低、可编程和全数字化、便于集成等突出优点、成为现代频率合成技术中的佼佼者，得到越来越广泛的应用，成为众多电子系统中不可缺少的组成部分。 本文介绍一种以AT89S52、AD9850和8279为核心器件的DDS正弦信号发生器。AD9850是一款专业极的正弦信号产生器件。它的特点正如上文所述的，电路整体结构简单，输出信号波形好，控制简单，而且易于实现程控。AT89S52和8279将在正文部分仔细的说明。 本次因为是毕业设计，我也首次采用12864LCD作显示器件。采用12864作显示器件的好处是可以显示汉字。 关键词：单片机，电压A/D转换，C语言 Title Function signal generator’s design and Realization Abstract Signal generator is a research, teaching experiments and a variety of electronic measurement technology is very important as a signal source, with the rapid development of science and technology, demands on the signal source more and more require the signal source frequency stability, higher accuracy and resolution to suit a variety of high-precision measurements, in order to meet this high demand, all countries in the development of a number of frequency synthesized signal source, such sources are normally a high stability and high accuracy degree of standard reference frequency source, using phase-locked with the same technologies used to produce millions of a degree of stability and accurate frequency signal source, in order to achieve high resolution and often using multiple phase-locked loop fractional-N technology, divider, mixer and filter links, so that frequency synthesis (DDS), and compared to the conventional frequency synthesis, DDS has a frequency resolution high frequency changes in speed, the output phase continuous, low phase noise, programmable and fully digital, easy integration and other advantages, become a modern leader in synthesizer technology, get more and more widely used, a large number of electronic systems an indispensable component.  This article describes a kind of AT89S52, AD9850 and 8