The microcomputer compensated crystal oscillator - practical application of dual-harmonic mode quartz thermometry

Author

Jackson, Edward

Author_Institution

Q-Tech Corp., Culver City, CA, USA

fYear

2004

fDate

23-27 Aug. 2004

Firstpage

401

Lastpage

405

Abstract

A precision frequency source based on dual harmonic mode quartz thermometry - Q-Tech´s microcomputer compensated crystal oscillator (MCXO) is described. System architecture, thermometry, compensation method, environmental and long-term performance characteristics are presented. Problems arising from the need to employ frequency synthesis and discrete-time compensation are addressed. Test results indicate that an initial frequency-temperature stability of 1E-8 over a temperature range of -50°C to +85°C is readily achievable, but that long-term stability depends upon the unique resonator. Aging characteristics that have not been previously characterized for precision clocks and the dependence of long-term stability on the differential aging rate between resonator harmonic modes are presented.

Keywords

ageing; compensation; crystal oscillators; frequency stability; thermal stability; -50 to 85 degC; MCXO; SiO₂; aging characteristics; crystal resonators; discrete-time compensation; dual-harmonic mode quartz thermometry; frequency synthesis; frequency-temperature stability; long-term stability; microcomputer compensated crystal oscillator; precision clocks; precision frequency source; resonator harmonic modes differential aging rate; Aging; Clocks; Frequency measurement; Frequency synthesizers; Microcomputers; Oscillators; Phase noise; Stability; Temperature dependence; Temperature distribution;

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.2004.1418489

Filename

1418489