基于FPGA的双路光纤激光拍频信号解调电路设计  

Design of demodulation circuit for dual-way fiber laser beat signal based on FPGA

作　　者：莫立涛 李宏伟[1,2] 湛晖 张昕明[1,2] 黄妍 吕国辉[1,2] MO Li-Tao;LI Hong-Wei;ZHAN Hui;ZHANG Xin-Ming;HUANG Yan;LV Guo-Hui(Heilongjiang University National and Regional Joint Engineering Research Center of Optical Fiber Sensing Technology,Harbin 150080,China;Heilongjiang University College of Electronic Engineering,Harbin 150080,China)

机构地区：[1]黑龙江大学光纤传感技术国家地方联合工程研究中心,哈尔滨150080 [2]黑龙江大学电子工程学院,哈尔滨150080

出　　处：《黑龙江大学工程学报》2021年第4期51-58,共8页Journal of Engineering of Heilongjiang University

基　　金：黑龙江大学JM融合资助项目(HDJMRH201904)。

摘　　要：设计了一种基于FPGA的拍频信号解调电路用于实时解调双路光纤激光的频差信息。应用ADF4351频率合成器芯片与ADL5801混频器芯片组成混频电路,设计了将光电探测器响应的射频(radio frequency,RF)域拍频信号下变频为中频(intermediate frequency,IF)信号的调理电路;以5CGXFC5C6F27C7N芯片为核心并结合快速傅里叶变换(FFT)进行时频转换,实现了拍频信号实时解调的FPGA解调电路。实验证明,该电路可实现0.41~3.45 GHz宽频带范围内的拍频信号实时检测,频率分辨率为7.6 kHz。A beat signal demodulation circuit based on FPGA is designed for real-time demodulation of the frequency difference information of dual-way fiber laser.The mixing circuit is composed of ADF4351 frequency synthesizer chip and ADL5801 mixer chip,and the conditioning circuit is designed to convert the beat signal in the RF domain to the IF signal.Based on 5CGXFC5C6F27C7N chip and combined with Fast Fourier Transform(FFT)for time-frequency conversion,the FPGA demodulation circuit for real-time demodulation of beat signal is realized.Experimental results show that the circuit can realize real-time detection of beat signal in the broadband range of 0.41~3.45 GHz,and the frequency resolution is 7.6 kHz.

关 键 词：双路激光信号 中频信号调理电路 FPGA解调电路 拍频检测 

分 类 号：TN248.4[电子电信—物理电子学]