Analysis and Design of an Improved Servo System for Rubidium Atomic Frequency Standard  

作　　者：CHEN Yongtai XU Donghui SHEN Yanxin YE Sen TANG Jing SU Lijuan 

机构地区：[1]School of Information Engineering, Wuhan University of Technology [2]Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences

出　　处：《Wuhan University Journal of Natural Sciences》2013年第1期67-72,共6页武汉大学学报（自然科学英文版）

摘　　要：In this paper, we analyze and design a new type of servo system with noninteger voltage controlled crystal oscillator （VCXO） for rubidium atomic frequency standard （RAFS）, which does not require fractional frequency synthesizer. By the estab- lishment of the loop equations with noises and drifts, we prove that all the components of the loop can affect its performance in- dex, and in which, RAFS long-term frequency stability is mainly determined by frequency multiplier, quantum system, and servo amplifier; the short-term one is mostly decided by VCXO. Owing to the elimination of the frequency synthesizer and its additive mixing unit, we can reduce phase noise and stray of the servo sys- tem, and it is favorable for miniaturizing the RAFS system. In addition, we adopt some targeted optimization measures to im- prove the frequency stability index. The good short-term fre- quency stability index is also validated by the test results.In this paper, we analyze and design a new type of servo system with noninteger voltage controlled crystal oscillator （VCXO） for rubidium atomic frequency standard （RAFS）, which does not require fractional frequency synthesizer. By the estab- lishment of the loop equations with noises and drifts, we prove that all the components of the loop can affect its performance in- dex, and in which, RAFS long-term frequency stability is mainly determined by frequency multiplier, quantum system, and servo amplifier; the short-term one is mostly decided by VCXO. Owing to the elimination of the frequency synthesizer and its additive mixing unit, we can reduce phase noise and stray of the servo sys- tem, and it is favorable for miniaturizing the RAFS system. In addition, we adopt some targeted optimization measures to im- prove the frequency stability index. The good short-term fre- quency stability index is also validated by the test results.

关 键 词：rubidium atomic frequency standard （RAFS） servo loop frequency stability non-integer voltage controlled crystal oscillator （VCXO） 

分 类 号：TN710[电子电信—电路与系统]