基于DSP的低频频率特性测试仪

传统的频率特性测试仪不仅价格昂贵，且得不到相频特性，更不能保存频率特性图和打印频率特性图，也不能与计算机接口，给使用者带来了诸多不便。而本文采用DDS技术作为扫频信号源；同时采用了集成模拟芯片AD8302对幅度和相位进行检测，用DSP芯片TMS320VC5409 和CPLD芯片EPM7128进行测量控制和数据处理，人机接口部分是利用单片机AT89C51实现，并配有打印机接口和串行通信接口。系统基本达到了全数字化，这有利于缩小仪器的体积，减轻重量，降低成本，并能较好的显示幅频特性和相频特性曲线。

Abstract:

 Traditional tester for frequency characteristic not only had high price， but also couldn’t give phase frequency characteristic of the quizzed network， yet couldn’t save and print frequency characteristic and couldn’t connet with PC.These gave user a lot of discommodity. However， adoptting the DDS technology as a sweep frequency signal source， using the AD8302 of integrated simulation chip to test amplitude and phase and using the TMS320VC5409 of DSP chip and the EPM7128 of CPLD chip to control measuring and process data. The section of man-machine interface uses the AT89C51 of SCM to realize， and has the printer and serial communication of the interfaces. The system reaches a basic all-digital， which make for shrinking the size， reducing the weight and the cost of equipment， moreover can display the characteristic curve of amplitude and phase preferably.