基于FPGA的数字锁相放大器在气体探测中的应用  

Application of FPGA-based Digital Lock-in Amplifier in Laser Gas Detection

作　　者：范松涛[1] 周燕[1] 张强[2] 潘教青[3] 

机构地区：[1]中国科学院半导体研究所光电系统实验室,北京100083 [2]北京光电技术研究所,北京100010 [3]中国科学院半导体研究所光电子研究发展中心,北京100083

出　　处：《计算机测量与控制》2012年第11期3027-3028,3041,共3页Computer Measurement &Control

基　　金：国家高技术研究发展计划(863计划)(2009AA03Z442)

摘　　要：介绍了基于波长调制光谱技术的激光气体探测系统的基本原理,详细描述了双相数字锁相放大器基本原理和结构;为了实现模块化高精度在线激光气体检测系统,利用FPGA和模数数模器件设计了数字锁相放大器的硬件电路,将数字锁相算法在FPGA中实现;基于FPGA的数字锁相放大器应用于激光甲烷分析仪中,并对4个标准甲烷气体进行了实际测试,在10%量程范围内示值误差不超过±0.2%;实验表明基于FPGA的数字锁相放大器能够用于高精度在线激光气体探测系统中。The basic principle of laser gas detection system based on wavelength modulation spectroscopy is introduced. The basic princi pie and structure of dual phase digital lock in amplifier is described in detail. In order to achieve the modular high--precision laser gas on line detection system, a hardware circuit board is desgined which includes FPGA , ADC and DAC. The digital lock--in algorithm is implim ented in the FPGA chip. Four standard methane samples were tested by the laser methane analyzer using FPGA--based digital lock--in am plifier, indication error is less than±0.2 % at the full scale of 10 %. The experiment results show that FPGA--based digital lock--in ampli tier can be used for high--precision laser gas detection system.

关 键 词：数字锁相放大器 TDLAS FPGA 二次谐波 

分 类 号：TN216[电子电信—物理电子学]