Wave transmission lines and networks – Coupling networks – Electromechanical filter
Reexamination Certificate
2005-12-06
2005-12-06
Summons, Barbara (Department: 2817)
Wave transmission lines and networks
Coupling networks
Electromechanical filter
C333S195000, C029S025350
Reexamination Certificate
active
06972642
ABSTRACT:
The invention provides a surface acoustic wave device capable of precisely controlling a frequency, of reducing changes in the center frequency with the lapse of time after controlling the frequency, and of performing a stable operation for a long time. The thickness of an IDT electrode formed on a quartz substrate is set to be slightly larger than the desired thickness so that the center frequency is slightly lower than the desired frequency. Next, a voltage is applied to the IDT electrode and the center frequency is measured. At this time, the measured center frequency is slightly lower than the desired frequency. The rear surface of the quartz substrate is etched while checking the measured center frequency. As a result, the measured center frequency gradually increases and approaches the desired frequency by etching the rear surface of the quartz substrate. Further, the rear surface of the quartz substrate is continuously etched until the center frequency is the desired frequency. The etching is stopped at the point of time where the measured center frequency is the desired frequency.
REFERENCES:
patent: 6321444 (2001-11-01), Yatsuda et al.
patent: 6762537 (2004-07-01), Kikushima
patent: 6781484 (2004-08-01), Matsuta
patent: A 63-305604 (1988-12-01), None
patent: A 3-19406 (1991-01-01), None
patent: A 9-162691 (1997-06-01), None
patent: A 2000-156620 (2000-06-01), None
patent: A 2002-33633 (2002-01-01), None
patent: A 2003-69380 (2003-03-01), None
K. Weiss et al.; “SAW Resonators Frequency Trimming By Plasma Etching”, European Frequency Time Forum, 1996 IEE Conference Publication No. 418, pp. 155-158, Mar. 1996.
R. Subramanian et al.; “Production Trimming of SAW Devices Using CF4Chemistry and its Effects on SAW Characteristics”, 1996 IEEE Ultrasonics Symposium Proceedings, vol. 1, pp. 255-260, Nov. 1996.
Oliff & Berridg,e PLC
Seiko Epson Corporation
Summons Barbara
LandOfFree
Method of controlling frequency of surface acoustic wave... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of controlling frequency of surface acoustic wave..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of controlling frequency of surface acoustic wave... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3516170