title: A low noise and ultra-narrow bandwidth frequency-locked loop based on the beat method.
abstract: A novel frequency-locked loop (FLL) based on the beat method is proposed in this paper. Compared with other frequency feedback loops, this FLL is a digital loop with simple structure and very low noise. As shown in the experimental results, this FLL can be used to reduce close-in phase noise on atomic frequency standards, through which a composite frequency standard with ultra-low phase noise and low cost can be easily realized.
authors.affiliation: Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Gao
authors.forename: Jianping
authors.initials: J
authors.lastname: Sui
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Chen
authors.forename: Fang
authors.initials: F
authors.lastname: Yu
authors.forename: Rongwu
authors.initials: R
authors.lastname: Sheng