高频小信号频率计的设计  

Design of High Frequency Small Signal Frequency Meter

作　　者：李江坤[1] 李阳[1] 李可人[1] 

机构地区：[1]太原科技大学电子信息工程学院,山西太原030024

出　　处：《山西电子技术》2016年第2期26-27,共2页Shanxi Electronic Technology

基　　金：太原科技大学大学生创新创业计划项目(Xj2014069)

摘　　要：本方案设计的频率计由衰减电路、宽带通道放大器、整形电路、FPGA测量模块、STM32单片机最小系统组成。设计了一个放大倍数为40 d B的两级宽带通道放大器,将10 m V(有效值)的信号放大到1 V(有效值)左右。第一级使用OPA847实现了26 d B的放大,第二级使用THS3201实现了14 d B的放大。当被测信号幅度较大时,使用衰减网络将被测信号衰减到10 m V左右。放大后的信号整形后产生相同频率的方波信号,使用Cyclone IV FPGA芯片实现等精度法测量频率、时间间隔和占空比。测量结果通过串口传给STM32单片机系统进行相关处理和显示。This project consists of following modules： the damping circuit,wideband pass amplifier,reshaping circuit,FPGA measure module and the minimum units of STM32 single chip microcomputer. The paper designs a double amplifier with magnification of 40 d B which can amplify the valid values of signal from 10 m V to 1 V. The first stage uses OPA847 to realize the amplification of 26 d B,while the second stage uses the THS3201 to realize 14 d B. When the measured signal amplitude is high,the signal will be attenuated to 10 m V by the damping circuit. The reshaped signal produces a same frequency square wave signal. It uses the equal precision measurement method to measure frequency,time interval and duty cycle by Chip Cyclone IV FPGA. The measurement is transmitted to the STM32 single chip system through the serial for relevant processing and display.

关 键 词：STM32单片机 FPGA 等精度法 宽带通道放大器 

分 类 号：TM935.13[电气工程—电力电子与电力传动]