Electrical generator or motor structure – Non-dynamoelectric – Piezoelectric elements and devices
Patent
1985-05-28
1987-10-20
Wong, Peter S.
Electrical generator or motor structure
Non-dynamoelectric
Piezoelectric elements and devices
310361, 310312, H01L 4108
Patent
active
047016612
ABSTRACT:
SC cut crystal resonators having lateral field excitation are disclosed. An SC cut quartz crystal blank is a doubly rotated Y cut which has the very valuable characteristic that its resonance frequency is stable while under stress, either from temperature gradients or from shock and vibration. Because of the threefold symmetry of quartz, and since the SC cut is rotated 22 degrees about the Z axis, there is a Y axis only about 8 degrees from the surface of an SC cut plate. A lateral field directed along or near this axis strongly excites the C mode and very weakly excites the B mode, if at all. The electrodes generating the lateral field are placed on the same major surface of an SC cut quartz crystal disc element and shaped to place the strongest field in the center of the disc element. This has been found to strongly couple to the C mode and suppress all other modes including the B mode and satellite C modes. Spectral purity and Q are enhanced thereby. Also, since the electrodes are disposed on only one major surface of the disc, the other major surface is unencumbered and available for frequency adjustment. The angle which the field forms with the Z' axis determines the relative degree of coupling of the B and C modes. At an angle of about +110.degree., optimal coupling is obtained for the C mode while the B mode is substantially suppressed. At about +160.degree., optimal suppression of the B mode is obtained while coupling of the C mode remains strong. At about +60.degree., approximately equal coupling of the B and C modes is obtained.
REFERENCES:
patent: 3165651 (1959-12-01), Bechmann
patent: 3202846 (1963-04-01), Ballato et al.
patent: 4211947 (1980-07-01), Ikeno et al.
patent: 4375604 (1983-03-01), Vig
A. Warner et al., "Low `g` Sensitivity Crystal Units and Their Testing", Proc. 33rd Ann. Freq. Control Symp., USAERADCOM, Ft. Monmouth, NJ 07703, Jun. 1, 1979, pp. 306-311.
B. Goldfrank et al., "Further Developments on `SC` Cut Crystals", Proc. 34th Ann. Freq. Control Symp., USAERADCOM, Ft. Monmouth, NJ 07703, May 1980, pp. 183-186.
B. Goldfrank et al., "Update of SC Cut Crystal Resonator Technology", Proc. 35th Ann. Freq. Control Symp., USAERADCOM, Ft. Monmouth, NJ 07703, May 27, 1981, pp. 92-97.
B. Goldfrank et al., "Further Development in SC Cut Crystal Resonator Technology", Proc. 36th Ann. Freq. Control Symp., USAERADCOM, Ft. Monmouth, NJ 07703, Jun. 2, 1982, pp. 208-221.
A. Warner, "Use of Parallel Field Excitation in the Design of Quartz Crystal Units", Proc. 17th Symp. Freq. Control, 1963, pp. 248-266.
E. R. Hatch et al., "Later-Field Excitation of Quartz Plates" Proc. IEEE Ultrasonics Symp., Oct.-Nov. 1983, pp. 512-515.
Government Contract No. DAAK20-83-C-0418, Aug. 22, 1983, pp. 1 & 6-8.
A. Ballato, et al., "Lateral-Field Excitation of Berlinite", U.S. Army Electronics Technology & Devices Laboratory, Ft. Monmouth, NJ 07703.
R. Bechmann, "Improved High-Precision Quartz Oscillators Using Parallel Field Excitation", Reprint from the Proceedings of the IRE, vol. 48, No. 3, Mar. 1960.
A. Warner, et al., "Fundamental Studies of Aging in Quartz Resonators, published in the IEEE Transactions on Sonics and Ultrasonics, Jun. 1965, pp. 52-59.
Final Report for Contract No. DA-91-591-EUC-1752, "The Stability and Q-Factor of Quartz Crystals Excited by the Parallel Field Technique", May 1, 1961 to Apr. 30, 1963.
Goldfrank Bruce
Warner Arthur W.
Frequency Electronics, Inc.
Todd Voeltz Emanuel
Wong Peter S.
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