A hybrid digital/analog servo for the NIST-7 frequency standard

Author

Lowe, J.P. ; Lee, W.D. ; Walls, F.L. ; Drullinger, R.E.

Author_Institution

Time & Frequency Div., Nat. Inst. of Stand. & Technol., Boulder, CO, USA

fYear

1994

fDate

1-3 Jun 1994

Firstpage

662

Lastpage

665

Abstract

This paper describes a hybrid (analog/digital) approach to the servo electronics for the NIST-7 cesium-beam frequency standard. A digital servo system has been added to the existing analog system to enhance the capabilities of both servos. The analog servo allows a 5 MHz oscillator to be frequency locked directly to the atomic transition frequency. The digital servo reduces the frequency perturbations due to changes in the ambient magnetic field. Also, the existence of separate servo systems allows independent measurements of systematic errors. Design specifications are given and stability measurement results are presented

Keywords

Zeeman effect; atomic beams; atomic clocks; caesium; digital control; frequency measurement; frequency stability; measurement standards; physical instrumentation control; servomechanisms; 5 MHz; 5 MHz oscillator; Cs; NIST-7 cesium-beam; NIST-7 frequency standard; atomic transition frequency; frequency locked oscillator; frequency standard; hybrid digital/analog servo; servo electronics; stability measurement; systematic errors; Clocks; Distortion measurement; Fluctuations; Frequency conversion; Frequency synthesizers; Magnetic field measurement; Magnetic shielding; Masers; Phase noise; Servomechanisms;

fLanguage

English

Publisher

ieee

Conference_Titel

Frequency Control Symposium, 1994. 48th., Proceedings of the 1994 IEEE International

Conference_Location

Boston, MA

Print_ISBN

0-7803-1945-1

Type

conf

DOI

10.1109/FREQ.1994.398264

Filename

398264