摘要
锁相环(PLL)的基本频率特性主要是由环路滤波器决定的.为了节省锁相环的设计仿真时间,提高设计效率,提出一种基于ADS仿真平台的环路滤波器系统级设计与仿真方法.分析RC无源滤波器截止频率与锁相速度之间的关系;引入滞后超前滤波器结构,提高PLL的稳定性,还分析滞后超前滤波器的幅度-频率特性,以及影响相位返回量的因素,并基于ADS仿真平台分析相位返回量的大小与环路锁相速度之间的关系,为环路滤波器设计提供理论依据.
the basic performance of phase locked loop(PLL) was mainly determined by the loop filter.In order to save the simulation time and improve the design efficiency,a kind of system-level design and hybrid simulation way was applied to loop filter design based on ADS software platform.The relationship between cut-off frequency and the phase-locking speed of RC delay filter was analyzed.In order to improve the stability of PLL,the lag-lead filter structure was introduced.Furthermore,the amplitude-frequency characteristics and factors of affecting the phase margin were analyzed in the lag-lead filter.Finally,the relationship between the phase margin and the Phase-locked speed was worked out based on ADS software,which provided theory references for loop filter design.
出处
《湖北大学学报(自然科学版)》
CAS
北大核心
2011年第4期494-497,共4页
Journal of Hubei University:Natural Science
基金
湖北省教学研究项目(2009164)资助