基于直接数字合成的扫频测试电路设计

本文首先对扫频信号测试系统中的重要模块：扫频信号源进行了深入的研究与分析，
详细推导了扫频电路测试原理与理论依据。在对比了多种信号产生方法的优缺点后，提出
了基于直接数字合成的扫频测试电路具体实现方案，重点探讨了直接数据合成芯片与控制
单片机之间的通信方法和实现电路。最后对实现的扫频信号源中的合成信号质量进行分
析，给出了实际电路与理想状态下的信号图。
关键词: 扫频信号；测试系统；DDS；电路；质量分析；
Abstract: At first this paper has deeply researched and analyzed the important module Frequencies-Scanning signal source in the Frequencies-Scanning signal Measurement system,
in detail inferred the test principle and the theory basis of Frequencies-Scanning circuit. After
contrasted several kinds of signals generate ways, has proposed the concrete realization plan of
the Frequencies-Scanning Measurement Circuit Based on DDS. has discussed the means of
communication between the DDS chip and the microcontroller chip, besides that the realization
electric circuit has been given. At last, has analyzed the synthesis signals quality generated form
the frequencies-scanning signal source. has produced the actual electric circuit and the perfect
condition signal chart.
Keyword: frequencies-scanning signal; measurement system; DDS ;circuit; quality analysis