摘要
大捕获带宽的同步给传统二阶锁相环带来了巨大挑战。文中针对传统锁相环捕获带宽与抑制噪声能力两者之间的矛盾,提出一种耦合非线性环节的新型二阶锁相环,利用非线性模块自适应调整环路噪声带宽。输入输出相位误差较大时利用较大的带宽迅速减小频偏;当相位误差由于环路控制作用而减小时,利用较小的带宽抑制噪声以提高跟踪精度。仿真结果表明,非线性二阶锁相环跟踪速度显著提高,且相比传统二阶锁相环,捕获带宽从4 kHz最大提高到18. 8 kHz。
The large acquisition bandwidth presents a significant challenge to traditional second-order phase locked loops.On the basis of the contradiction of larger acquisition bandwidth and noise reduction capabilities,a novel second-order PLL which was coupled with a nonlinear element,was introduced in this paper.The loop noise bandwidth was adaptively adjusted by the nonlinear element.The frequency error was reduced more quickly with a larger bandwidth when the frequency error was large.By contrast,the noise was suppressed with a smaller bandwidth to improve the tracking accuracy when the frequency error was reduced due to the control effect of the loop.The simulation results indicated that the tracking speed of the proposed nonlinear second order PLL was significantly increased and the acquisition bandwidth was increased from4kHz to18.8kHz.
作者
赵蕾
石磊
朱从莹
姚博
ZHAO Lei;SHI Lei;ZHU Congying;YAO Bo(School of Information,Xi’an University of Finance and Economics,Xi’an 710100,China;School of Aerospace Science and Technology,Xidian University,Xi’an 710071,China)
出处
《电子科技》
2019年第1期1-4,10,共5页
Electronic Science and Technology
基金
国家自然科学基金(61473228
61301173)
陕西省自然科学基金(2016JM06)
西安财经学院科学研究扶持计划(16FCJH03)~~
关键词
锁相环
捕获带宽
跟踪精度
自适应
频率相位误差
环路噪声带宽
phase locked loop
acquisition bandwidth
tracking accuracy
adaptive
frequency-phase error
loop noise bandwidth
