文档介绍：2013电子竞赛简易频率测试仪————————————————————————————————作者:————————————————————————————————日期: 简易频率特性测试仪(E题)摘要:该简易频率特性测试仪采用STM32F103ZET6核心板,主要由自制正交扫描信号源、RLC被测网络、乘法器、低通滤波等功能模块组成;测试数据包含信号的幅频特性及相频特性,于彩屏TFT上显示。本系统利用高速DDS(AD9854)模块实现信号发生电路,能输出双端口的正交信号,并可控制设置其幅值与频率。被测网络采用RLC串联谐振电路,达到要求的网络通带中心频率。将DDS产生的正交信号和被测网络信号通过乘法器AD835模块,经LTC1564低通滤波,利用单片机上的片上AD进行采样,最终在彩屏上显示输出,完成对信号的幅频和相频的简单测试。关键词:STM32;DDS;乘法器;滤波;TFTAbstract:Thesimplefrequencytesterisbasedonhigh-performanceSTM32F103ZET6controller,anditmainlyconsistsofself-maidsignalgenerator,work,multipliers,low--frequencycharacteristicsandphase-frequencycharacteristics,-speedDDS(AD9854)blockassignalcircuit,generatingthedual-portquadraturesignals,,-passfilter,andwillbesampledbythe12-biton--frequencyandphase-:STM32;DDS;multiplier;filter;TFT一、方案选择与论证································································································································································································································4二、电路设计···········································································································································································································5三、系统设计···························································································································································································································