文档介绍：燕山大学
毕业设计(论文)
基于锁相环的可编程信号发生器
学院(系)里仁学院
年级专业 04级电子信息(1)班
学生姓名蒋超
指导教师王成儒
答辩日期
摘要
文章研究一种利用锁相环频率合成技术和数字波形合成技术组成的程控低频正弦波信号发生器,,稳定性好,且失真度很低,电路简单,可靠,便于程控,可作为标准正弦信号源应用于高准确度仪表中
本文首先介绍了研究课题的背景,既频率合成技术的发展,应用,现状。然后介绍了信号发生器的相关知识,锁相环技术和直接频率合成计数的功能和应用。在第二章介绍了关于频率合成、锁相环频率合成、DDS频率合成、PLL+DSS频率合成等的基本理论。然后分析了PLL+DSS频率合成系统在具体设计中应该考虑的问题。最后在第三章详细叙述了本课题采用的方案、各个模块的功能实现、实际设计中应该注意的问题。
本文所采用的PLL+DSS频率合成方法可以将DDS的超高频率分辨率、高频率精确度、容易实现程控等优点与锁相环良好的窄带跟踪滤波特性相结合,从而实现系统所要求的宽带扫频功能及相应的技术指标。
关键词锁相环 DDS 频率合成标准正弦波
Abstract
This paper studies a program-controlled low-frequency sinusoidal generator by means of phase-locked loop frequency synthesizer and digital wave synthesizer technology. Its frequency distinguish ratio is Hz Output-sinewave frequency and range is high precision,well stabilty and at much low circuit is simple,reliable and programmable controlled It can be used in high accuracy device as standard sine wave signal generator.
This article first introduced the research subject background, also frequency synthesis technology development, application, present situation. Then introduced the signal generating device related knowledge, the phase-locked loop technology and the direct frequency synthesis counting function and the application The basic theories of the frequency synthesis, PLL,DDS,DDS+PLL a re introduced at the second chapter in this paper. Subsequently, some questions about the design of the system on frequency synthesis are discussed. At last, the scheme of subject, the functional realization of each module, some questions which must be pay much attention in the system design,
The hybrid frequency synthesis technology一DDS+PLL used in the subject have many this method,the merits of DDS such as super fine frequency resolution, high frequency accuracy, easy programmed can be bination with the excellent character of narrow-band tracing filter merits of PLL. Thereby, the wideband sweep function and speci