2013年全国大学生电子设计竞赛 简易频率特性测试仪（E题） 【本科组】 2013年 9 月7日 1 摘 要 摘要：本系统是基于FPGA和STM32作为主系统，由控制两片高速DAC900，产生两路相正 交的扫频信号(1MHZ—40MHZ)，而STM32作为整个系统的主控系统。通过STM32控制扫频信号 输出实现闭环稳幅，再通过乘法器 AD835实现扫频信号与被测网络出来信号的混（倍频）， 再通过RC低通滤波，用STM32内部AD采集测出并显示幅频特性与相频特性，显示在彩屏中， 是一款很不错的简易频率特性测试仪。很好的实现了题目的要求以及大部分的发挥部分。 关键字：扫频信号 FPGA STM32 混频 乘法器 【Abstract】 The system is based on FPGA and STM32 as the main system, controlled by the two high-speed DAC900, generates two orthogonal sweep signal (1MHZ-40MHZ), while the STM32 master control system as a whole system. STM32 sweep signaloutputviaclosed-loopcontrolleveled,andthenthroughthemultiplierAD835 achieve sweep signal and the measured network out mixed signals (frequency), and then through an RC low-pass filter, with the STM32 internal AD collection and displays the measured amplitude-frequency characteristic and phase-frequency characteristics, shown in color, the simplicity is a very good frequency characteristics tester. Achieved a very good and most of the requirements of the subject play a part. Key Word: Frequency sweep signalFPGA STM32 mixing mul