The "Digital Indirectly Compensated Crystal Oscillator" (DICXO); a high-performance clock for aircraft landing applications

D. Domey, J.C. Lanoue and J. Studenny

Abstract:	This paper discloses a new crystal clock oscillator technology, the DICXO1. It describes its implementation, the production test equipment and processes developed by CMC to calibrate the DICXO and to check for residual "micro-jumps". "Micro-jumps" are occasional, microscopic clock frequency steps that are induced by temperature variations. The amplitude of the micro-jumps for conventional crystal clocks can cause momentary loss of GPS signal tracking. Thus micro-jumps can degrade the continuity of navigation service, a critical issue for aircraft landing applications. Continuity of function, up to and including CAT-IIIb, was the main reason for developing this technology. The DICXO technology allows a significant reduction o the amplitude of micro-jumps, solving the problem o continuity of operation; furthermore it reduces the thermal transient errors, thereby improving system performance under conditions of fast temperature variations.
Published in:	Proceedings of the 15th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 2002) September 24 - 27, 2002 Oregon Convention Center Portland, OR
Pages:	1619 - 1629
Cite this article:	Domey, D., Lanoue, J.C., Studenny, J., "The "Digital Indirectly Compensated Crystal Oscillator" (DICXO); a high-performance clock for aircraft landing applications," Proceedings of the 15th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 2002), Portland, OR, September 2002, pp. 1619-1629.
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