DocumentCode :
2985203
Title :
A phase locked mechanism for time scaling frequency control system
Author :
Lin, ShinnYan
Author_Institution :
Telecommun. Labs., Chunghwa Telecom Co, Chung-li, Taiwan
fYear :
2004
fDate :
23-27 Aug. 2004
Firstpage :
478
Lastpage :
481
Abstract :
A new mechanism is developed for a time scaling frequency control system. Our purpose is to use this mechanism to convert a virtual paper clock time scale into a physical output. We simulate the phase locked loop to control two micro-phase steppers and force them to track the phase variation of the virtual paper clock. A proportional control law with a damping factor was used for controlling the micro-phase steppers. In the result, the two micro-phase steppers are synchronized with the paper clock successfully. The phase difference between two micro-phase steppers and paper clock all were kept in ±300 ps during 100 days, and the related Allan deviation was about 8E-14 (tau = 600 seconds). We create more than one identical system and the systems keep both short-term performance of hydrogen maser and long-term accuracy of a cesium clock ensemble time scale without prediction algorithm. Our mechanism is also helpful for setting up a backup time scaling system, the primary and backup system is kept in phase without any extra artificial adjustment.
Keywords :
atomic clocks; damping; frequency control; masers; phase locked loops; proportional control; Allan deviation; cesium clocks; damping factor; hydrogen masers; long-term accuracy; micro-phase steppers; phase locked loop; phase variation tracking; proportional control law; short-term performance; time scaling frequency control; virtual paper clock time scale; Clocks; Damping; Force control; Frequency control; Frequency synchronization; Hydrogen; Masers; Phase locked loops; Proportional control; Tracking loops;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Frequency Control Symposium and Exposition, 2004. Proceedings of the 2004 IEEE International
ISSN :
1075-6787
Print_ISBN :
0-7803-8414-8
Type :
conf
DOI :
10.1109/FREQ.2004.1418505
Filename :
1418505
Link To Document :
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