THE STABILITY AND Q-FACTOR OF QUARTZ-CRYSTALS EXCITED BY THE PARALLEL FIELD TECHNIQUE
Abstract
The development of parallel field excited crystals was studied with the e of obtain ing quartz crystal resonators having high Q and low aging. The electrical parameters of parallel field excited crystals and their variation as a function of the plating pattern were investigated. Quality factors of six million were obtained with a gap of about 1mm. Parallel field excited crystals with wide gap showed Q's up to ten mil lion. This led to the conclusion that the main factor limiting Q is the damping due to the metal film deposited on the surface of the crystals, especially in the center. Series of measurements were carried out with the normal field excitation using annular electrodes, which is the reversed method as compared to conventional plating. An increase of the central unplated area is followed by an increase of the Q-value, which confirmed the above conclusion. An attempt was made toward the elimination of the weak points of both de scribed methods, i.e. too high inductance in case of the parallel field and too high capacity in case of the normal field excitation using annular electrodes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 30, 1963
- Accession Number
- AD0410296
Entities
Organizations
- Paris Observatory, PSL University