US3568108A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin film piezoelectric filter
Assignee: Lockheed Martin Corp
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Filing: 1968-05-31
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Granted: 1971-03-02
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Expires: 1988-05-31
Abstract
Abstract A thin film piezoelectric filter comprises a plurality of coaxially disposed resonators; each having a different but overlapping frequency-amplitude characteristic. The individual resonators are separated from one another by a selectively transmissive structure such that high-frequency acoustic waves produced in a first resonator are coupled in part to an adjacent resonator.
Inventors
- 👤 Armand R Poirier
- 👤 Terry F Newkirk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:42
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/46; H03H9/54; H03H9/58; H03H9/582; H03H9/583; H03H9/584; H03H9/586; H03H9/589
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
166 words
A thin film piezoelectric filter comprising: a plurality of resonators coaxially disposed in acoustical series with respect to one another, each said resonator having a different but overlapping acoustic frequency-amplitude characteristic and each including: an epitaxial film having both piezoelectric and semiconductive properties; electrically conductive means disposed adjacent opposed surfaces of each said epitaxial film for defining an acoustically resonant cavity in at least a portion of the transverse dimension of said film; means for applying a high-frequency electric field across a first one of said resonators to thereby produce high-frequency acoustic waves in said acoustically resonant cavity therein; means disposed between said resonators for selectively transmitting acoustic wave energy of a preselected frequency whereby said transmitted acoustic wave energy produced in the acoustically resonant cavity of said first resonator is coupled to the acoustically resonanT cavity of a second one of said resonators thereby producing high-frequency electric waves in said cavity; and means coupled to said second resonator for coupling said highfrequency electric waves therefrom.
Claim 2
Dependent Claim
166 words
A thin film piezoelectric filter comprising: a plurality of resonators coaxially disposed in acoustical series with respect to one another, each said resonator having a different but overlapping acoustic frequency-amplitude characteristic and each including: an epitaxial film having both piezoelectric and semiconductive properties; electrically conductive means disposed adjacent opposed surfaces of each said epitaxial film for defining an acoustically resonant cavity in at least a portion of the transverse dimension of said film; means for applying a high-frequency electric field across a first one of said resonators to thereby produce high-frequency acoustic waves in said acoustically resonant cavity therein; means disposed between said resonators for selectively transmitting acoustic wave energy of a preselected frequency whereby said transmitted acoustic wave energy produced in the acoustically resonant cavity of said first resonator is coupled to the acoustically resonanT cavity of a second one of said resonators thereby producing high-frequency electric waves in said cavity; and means coupled to said second resonator for coupling said highfrequency electric waves therefrom.
Claim 3
Dependent Claim
30 words
Apparatus as recited in claim 1 wherein the crystalline axes of each said epitaxial film are oriented such that said high-frequency acoustic waves produced therein are in the longitudinal mode.
Claim 4
Dependent Claim
30 words
Apparatus as recited in claim 1 wherein the crystalline axes of each said epitaxial film are oriented such that said high-frequency acoustic waves produced therein are in the shear mode.
Claim 5
Dependent Claim
51 words
Apparatus as recited in claim 1 wherein said selective transmitting means comprises a plurality of layers having alternately relatively high and relatively low characteristic acoustic impedance, each said layer being of a thickness between one-half wavelength of said acoustic wave and an odd number of quarter wavelengths of said acoustic wave.
Claim 6
Dependent Claim
61 words
Apparatus as recited in claim 1 a further including acoustic wave-reflecting means disposed adjacent said second resonator on the surface thereof opposite said selective transmitting means comprising a plurality of layers having alternately relatively high and relatively low characteristic acoustic impedance, each said layer being of a thickness substantially equal to an odd number of quarter wavelengths of said acoustic wave.
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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) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |