›› 2013, Vol. 26 ›› Issue (12): 110-.

• 论文 • 上一篇    下一篇

基于FPGA的LIA设计及其在光声检测中的应用

倪士虎,刘先勇,曹新丹,李进   

  1. (西南科技大学 信息工程学院,四川 绵阳 621010)
  • 出版日期:2013-12-15 发布日期:2014-01-10
  • 作者简介:倪士虎(1987—),男,硕士研究生。研究方向:嵌入式系统设计,光声光谱法气体检测。E-mail:841688062@qq.com

Design of the Lock-in Amplifier Based on FPGA and its Application in Photoacoustic Signal Detection

 NI Shi-Hu, LIU Xian-Yong, CAO Xin-Dan, LI Jin   

  1. (School of Information Engineering,South West University of Science and Technology,Mianyang 621010,China)
  • Online:2013-12-15 Published:2014-01-10

摘要:

设计并实现了基于FPGA的数字双相锁相放大器,并应用于光声瓦斯气体传感器的研究。通过对不同浓度瓦斯气体的测试结果表明,该锁相放大器可以有效提取微弱的光声信号,检测出气体的浓度,当气体浓度在0%~3%范围内变化时,锁相放大器的输出具有较好的线性度,低通滤波器的截止频率可达5 Hz,输入信号频率在10 kHz以内时系统输出具有较好的一致性。

关键词: 现场可编程门阵列, 锁相放大技术, DDS技术, FIR滤波器

Abstract:

A lock-in amplifier based on FPGA is designed and implemented with the Quartus II software of Altera and simulated in Modelsim.This lock-in amplifier is used in the photoacoustic gas sensor to detect CH4.The results show that it can extract weak signal from noise effectively and measure the concentration of CH4.For a gas concentration between 0%~3%,the output of lock-in amplifier has good linearity with a 5 Hz stop frequency of low pass filter.The output of system has good consistency when the frequency of input signal is below 10 kHz.

Key words: field programmable gate array;lock-in amplifier;DDS technology;FIR filter

中图分类号: 

  • TN721