Patent US4384229A successfully refreshed from Google Patents.
US4384229A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature compensated piezoelectric ceramic resonator unit
Assignee: NEC Corp
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Filing: 1981-02-10
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Granted: 1983-05-17
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Expires: 2001-02-10
Abstract
Abstract A thickness mode piezoelectric ceramic resonator is connected in series with a ceramic capacitor to form a piezoelectric ceramic resonator unit. When the ceramic capacitor has a capacitance Ca and the resonator is associated with a damped capacitor having a capacitance Co, these capacitances are related to each other by a relationship, Co</=Ca</=30 Co.
Inventors
- 👤 Takeshi Inoue
- 👤 Sadayuki Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:43
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/15; H03H9/17; H03H9/177; H03H3/00; H03H3/007; H03H3/02; H03H3/04; H03H9/02; H03H9/02007; H03H9/02086; H03H9/02102
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
125 words
A piezoelectric ceramic resonator unit comprising a thickness mode piezoelectric ceramic resonator and a ceramic capacitor connected in series with the resonator, wherein a capacitance Ca of said ceramic capacitor and a damped capacitance Co of said resonator have the following relationship Co≦Ca≦30Co, wherein (i) the temperature coefficient of said serially connected ceramic capacitor is different from that of said piezoelectric ceramic resonator; (ii) said ceramic capacitor has an aging characteristic such that the ratio of the capacitance Ca of said ceramic capacitor to the damped capacitance Co of said piezoelectric ceramic resonator, i.e. Ca/Co, increases as time elapses; and (iii) said ceramic capacitor has a positive temperature coefficient in its dielectric constant and a relatively small temperature dependent variation in its dielectric loss tangent.
Claim 2
Dependent Claim
125 words
A piezoelectric ceramic resonator unit comprising a thickness mode piezoelectric ceramic resonator and a ceramic capacitor connected in series with the resonator, wherein a capacitance Ca of said ceramic capacitor and a damped capacitance Co of said resonator have the following relationship Co≦Ca≦30Co, wherein (i) the temperature coefficient of said serially connected ceramic capacitor is different from that of said piezoelectric ceramic resonator; (ii) said ceramic capacitor has an aging characteristic such that the ratio of the capacitance Ca of said ceramic capacitor to the damped capacitance Co of said piezoelectric ceramic resonator, i.e. Ca/Co, increases as time elapses; and (iii) said ceramic capacitor has a positive temperature coefficient in its dielectric constant and a relatively small temperature dependent variation in its dielectric loss tangent.
Claim 3
Dependent Claim
18 words
A piezoelectric ceramic resonator unit according to claim 1 wherein the thickness mode is a thickness shear mode.
Claim 4
Dependent Claim
18 words
A piezoelectric ceramic resonator unit according to claim 1 wherein the thickness mode is a thickness extensional mode.
Claim 5
Dependent Claim
28 words
A piezoelectric ceramic filter comprising a plurality of piezoelectric ceramic resonator units as recited in claim 1, wherein said resonator units are arranged in a ladder type circuit.
Claim 6
Dependent Claim
28 words
A piezoelectric ceramic filter comprising a plurality of piezoelectric ceramic resonator units as recited in claim 1, wherein said resonator units are arranged in a Jaumann type circuit.
Claim 7
Dependent Claim
30 words
A piezoelectric ceramic filter comprising a plurality of piezoelectric ceramic resonator units as recited in claim 2 or 3, wherein said resonator units are arranged in a ladder type circuit.
Claim 8
Dependent Claim
30 words
A piezoelectric ceramic filter comprising a plurality of piezoelectric ceramic resonator units as recited in claim 2 or 3, wherein said resonator units are arranged in a Jaumann type circuit.
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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) | 1986-05-16 | 1986-11-15 | 1987-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-16 | 1990-11-15 | 1991-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-16 | 1994-11-15 | 1995-05-17 | $7700.00 | Window Closed / Lapsed |