Patent US3826931A successfully refreshed from Google Patents.
US3826931A
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Dual crystal resonator apparatus
Assignee: HP Inc
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Filing: 1971-02-08
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Granted: 1974-07-30
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Expires: 1991-02-08
Abstract
Abstract Algebraic combination of the frequencies of two or more selected modes of piezoelectric crystal resonator vibrations yields a total frequency signal output which has a substantially zero temperature coefficient of frequency.
Inventors
- 👤 D Hammond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:41
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/46; H03H9/54; H03H9/58; H03H9/60; H03L; H03L1/00; H03L1/02; H03L1/022; H03L1/027
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
139 words
Signal frequency apparatus comprising: first and second piezoelectric resonators of dissimilar crystallographic orientations, each having a coefficient of frequency with change of temperature and each being capable of vibrating substantially independently in accordance with its coefficient of frequency in response to vibration-exciting signal applied thereto; means disposed about said resonators to maintain substantially equal operating temperatures of said resonators for altering the vibration frequency thereof in accordance with the respective frequency coefficients; and circuit means including electrodes disposed about said resonators for applying vibration-exciting signals thereto to sustain the independent vibrations of said resonators at different frequencies which are in accordance with the respective coefficients of frequency thereof, and including apparatus for producing an output signal frequency having substantially zero temperature coefficient of frequency as the selected combination of frequencies derived from vibrations of the first and second resonators.
Claim 2
Dependent Claim
139 words
Signal frequency apparatus comprising: first and second piezoelectric resonators of dissimilar crystallographic orientations, each having a coefficient of frequency with change of temperature and each being capable of vibrating substantially independently in accordance with its coefficient of frequency in response to vibration-exciting signal applied thereto; means disposed about said resonators to maintain substantially equal operating temperatures of said resonators for altering the vibration frequency thereof in accordance with the respective frequency coefficients; and circuit means including electrodes disposed about said resonators for applying vibration-exciting signals thereto to sustain the independent vibrations of said resonators at different frequencies which are in accordance with the respective coefficients of frequency thereof, and including apparatus for producing an output signal frequency having substantially zero temperature coefficient of frequency as the selected combination of frequencies derived from vibrations of the first and second resonators.
Claim 3
Dependent Claim
96 words
Signal frequency apparatus as in claim 1 wherein: for each of said resonators the coefficient of frequency is a non-zero temperature coefficient; the first piezoelectric resonator is quartz having a theta o orientation between the theta angles of about 5 degrees and about 26* and a phi o orientation between the phi angles of about 50* and about 60*; and the second piezoelectric resonator is quartz having a theta o orientation between the theta angles of about 26* and about 42* and a phi o orientation between the phi angles of about 50* and about 60*.
Claim 4
Dependent Claim
95 words
Signal frequency apparatus as in claim 1 wherein: for each of said resonators the coefficient of frequency is a non-zero temperature coefficient; the first piezoelectric resonator is quartz having a theta o orientation between the theta angles of about 15* and about 26* and a phi o orientation between the phi angles of about 53* and about 60*, and the second piezoelectric resonator is quartz having a theta o orientation between the theta angles of about 26* and about 42* and a phi o orientation between the phi angles of about 50* and about 60*.
Claim 5
Dependent Claim
96 words
Signal frequency apparatus as in claim 2 wherein: the theta and phi orientations of the first and second resonators with respect to the values of theta o and phi o are: theta theta o phi phi o + m(120*), where m 1, 2, 3; and theta theta o phi 120* - phi o + m(120*), where m 1, 2, 3; and theta 180* - theta o phi phi o + 60* + m(120*), where m 1, 2, 3; and theta 180* - theta o phi 60* - phi o + m(120*), where m 1, 2, 3.
Claim 6
Dependent Claim
96 words
Signal frequency apparatus as in claim 3 wherein: the theta and phi orientations of the first and second resonators with respect to the values of theta o and phi o are: theta theta o phi phi o + m(120*), where m 1, 2, 3; and theta theta o phi 120* - phi o + m(120*), where m 1, 2, 3; and theta 180* - theta o phi phi o + 60* + m(120*), where m 1, 2, 3; and theta 180* - theta o phi 60* - phi o + m(120*), where m 1, 2, 3.
Claim 7
Dependent Claim
130 words
Signal frequency apparatus as in claim 1 wherein: each of said resonators vibrates in a mode which is characterized by known values of first, second and third order coefficients of frequency with change in temperature and for which the resonators have substantially equal ratios of second order to first order temperature coefficients, substantially equal ratios of third order to first order temperature coefficients, and unequal values of first order temperature coefficients; and said circuit means including the oscillator circuitry sustains vibration of said resonators in modes of vibrations for producing said output signal frequency which is substantially constant for changes in the temperature of the first and second resonators and which is at a frequency different from the vibration frequencies of at least one of the first and second resonators.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-29 | 1978-01-28 | 1978-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-29 | 1982-01-28 | 1982-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-29 | 1986-01-28 | 1986-07-30 | $7700.00 | Window Closed / Lapsed |