摘要
针对传统锁相环捕捉带和锁定动态范围有限的问题,对乘法运算型鉴相器作改进,采用动态过零检测器方案产生正向过零边沿脉冲;对于不同被测信号频率,推导精度误差最小化的频率计算模型,设计频率计完成边沿脉冲频率测量.对测量频率加权处理,指导频率合成器(DDS)输出单频信号,得到被测信号分频或倍频的正弦信号.理论分析结果表明,装置扩宽了捕捉带和跟踪范围至奈奎斯特采样频率的极限;ModelSim仿真表明,装置实现了对任意频率的直接测量和计算.通过对动态频率信号跟踪锁定实验,实现了调频信号的解调;通过替代平方环内锁相结构的实验,装置实现了DSB信号的载波恢复;通过AM信号解调实验,装置实现了AM导频信号的直接提取;采用ISE14.7软件环境分析,关键逻辑资源LUT消耗总数的4%.改进的设计可应用于调制解调、载波同步、信号产生等场合.
Aiming at the problem of limited dynamic range of traditional PLL capture band and locking,the multiplicative phase discriminator is improved,and a dynamic zero-crossing detector scheme is adopted to generate positive zero-crossing edge pulse.For different measured signal frequencies,the frequency calculation model with minimum accuracy error was derived,and the frequency meter was designed to measure the edge pulse frequency.The measurement frequency is weighted to guide the frequency synthesizer(DDS)to output the single-frequency signal and obtain the sinusoidal signal of frequency division or frequency doubling of the measured signal.The theoretical analysis results show that the device expands the capture band and tracking range to the limit of the Nyquist sampling frequency;ModelSim simulation shows that the device can directly measure and calculate arbitrary frequency.The demodulation of dynamic frequency signal is realized by tracking and locking experiment;by the experiment of replacing the phase-locked structure in the square loop,the device realizes the carrier recovery of the DSB signal;through the AM signal demodulation experiment,the device realizes the AM pilot frequency direct extraction of signals;using ISE14.7 software environment analysis,4% of the total LUT consumption of key logical resources was achieved.The improved design can be applied to modulation and demodulation,carrier synchronization,signal generation,etc.
作者
吴俊森
张超洋
文良华
WU Junsen;ZHANG Chaoyang;WEN Lianghua(Faculty of Intelligence Manufacturing,Yibin University,Yibin,Sichuan 644005,China;Intelligent Terminal Laboratory of Sichuan Province,Yibin,Sichuan 644005,China)
出处
《宜宾学院学报》
2021年第12期12-19,共8页
Journal of Yibin University
基金
四川省科技创新苗子工程培育项目(2021009)
四川省科技厅重点研发项目(2019YFN0104,21ZDYF3349)
宜宾学院培育项目(2020PY08)
宜宾学院课堂教学改革项目(JGQ202037)
宜宾学院校级教改项目(0819000102)。
关键词
过零检测
锁相环
频率计
频率跟踪
解调
over-zero detection
phase-locked loop
frequency meter
frequency tracking
demodulation
