基于数字化解调技术近红外光谱信号采集系统的研制  

Development of Signal Acquisition System for Near-infrared Spectrometer Based on Digital Demodulation

作　　者：刘志伟[1] 胡岚[1] 苏鹏飞[1] 刘红妮[1] 

机构地区：[1]西安近代化学研究所,陕西西安710065

出　　处：《仪表技术与传感器》2014年第7期90-93,共4页Instrument Technique and Sensor

摘　　要：采用数字化包络解调技术实现对近红外光谱信号的解调。设计实现了一种信号处理简单灵活的近红外光谱信号采集系统。选用型号为EPM240T100C5N的CPLD为系统扩展I/O口,并为ADS8505产生时序脉冲;单片机使用了STC89LE54RD+,以匹配CPLD 3.3 V电压。使用QuartusⅡ开发环境对CPLD内部程序进行设计。设计了总采样周期数对信噪比的影响实验,单周期采样点数对信噪比的影响实验,对系统进行检测与验证。与模拟解调电路相比,该系统数字信号处理简单灵活,精简了电路系统,减少了调试环节。A signal acquisition system for near-infrared spectrometer based on digital envelope demodulation technique were designed and implemented,which is simple and flexible for the handling of digital signal. In the system designed,CPLD EPM240T100C5 N,which has enough I /O ports for the system expansion and generates timing pulse to control ADS8505,was applied; STC89LE54 RD ＋ was used as the microcontroller. Quartus II development environment was used to design the CPLD internal program. Two tests of the influence of sampling period number to S /N and the influence of？ sampling points number of single cycle to S /N,were designed for detecting and verifying of the system. Compared with the phase-sensitive detection,this method is simple and flexible,greatly retrenched the circuit of the spectrometer and reduced the debugging steps.

关 键 词：近红外光谱 ADS8505 数字化解调 信号采集系统 

分 类 号：TH744[机械工程—光学工程]