US3686579A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solid-state, acoustic-wave amplifiers
Assignee: Zenith Electronics LLC
•
Filing: 1971-06-21
•
Granted: 1972-08-22
•
Expires: 1991-06-21
Abstract
Abstract In a signal amplifier, an input transducer launches acoustic surface waves at a given velocity along a predetermined path on a piezoelectric substrate. An output transducer responds to those waves for developing an output signal. A film of semi-conductive material between the input and output transducers responds to a unidirectional potential for conducting charge carriers alongside the propagation path at a velocity slightly greater than the acoustic wave velocity to achieve a amplification of the acoustic surface waves. Finally, a unidirectional field is applied transversely through the semi-conductive film to control the density of the charge carriers and the amplification.
Inventors
- 👤 Peter G Everett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:18
CPC Classifications
H; H03; H03F; H03F13/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
152 words
A signal amplifier comprising: a piezoelectric substrate propagative of acoustic surface waves; an input transducer on said substrate responsive to an input signal for launching acoustic surface waves along a predetermined path at a given velocity; an output transducer on said substrate responsive to said acoustic surface waves for developing an output signal; a film of semi-conductive material on said substrate between said input and output transducers responsive to an applied unidirectional potential for conducting charge carriers alongside said path; means for applying a unidirectional potential to said film with a magnitude adjusted to effect movement of said charge carriers at a velocity slightly greater than said given velocity to achieve amplification of said acoustic surface waves; and control means for applying a unidirectional field transversely through said film and said substrate for controlling the density of said charge carriers in said semiconductive material and the amplification of said acoustic surface waves.
Claim 2
Dependent Claim
152 words
A signal amplifier comprising: a piezoelectric substrate propagative of acoustic surface waves; an input transducer on said substrate responsive to an input signal for launching acoustic surface waves along a predetermined path at a given velocity; an output transducer on said substrate responsive to said acoustic surface waves for developing an output signal; a film of semi-conductive material on said substrate between said input and output transducers responsive to an applied unidirectional potential for conducting charge carriers alongside said path; means for applying a unidirectional potential to said film with a magnitude adjusted to effect movement of said charge carriers at a velocity slightly greater than said given velocity to achieve amplification of said acoustic surface waves; and control means for applying a unidirectional field transversely through said film and said substrate for controlling the density of said charge carriers in said semiconductive material and the amplification of said acoustic surface waves.
Claim 3
Dependent Claim
24 words
An amplifier as defined in claim 1 in which said control means includes field producing elements disposed respectively on opposite sides of said substrate.
Claim 4
Dependent Claim
33 words
An amplifier as defined in claim 1 in which said control means includes a strip of resistive material disposed on said substrate in a location spaced from said film to develop said field.
Claim 5
Dependent Claim
23 words
An amplifier as defined in claim 3 in which the charge-carrier mobility in said strip is substantially less than that in said film.
Claim 6
Dependent Claim
28 words
An amplifier as defined in claim 3 in which said strip is spaced from said film a distance at least one-half the wavelength of said acoustic surface waves.
Claim 7
Dependent Claim
25 words
An amplifier as defined in claim 3 in which said strip exhibits a potential gradient along its length substantially identical to that along said film.
Claim 8
Dependent Claim
73 words
In a signal transmission device in which acoustic surface waves propagate along a piezoelectric substrate and co-act with charge carriers traveling in a semi-conducting medium for the amplification of signal energy, the improvement comprising: a unidirectional potential coupled transversely of said medium for establishing a unidirectional electric field extending through said medium in a direction transverse to the direction of travel of said charge carriers to decrease the density of said charge carriers.
Claim 9
Dependent Claim
73 words
In a signal transmission device in which acoustic surface waves propagate along a piezoelectric substrate and co-act with charge carriers traveling in a semi-conducting medium for the amplification of signal energy, the improvement comprising: a unidirectional potential coupled transversely of said medium for establishing a unidirectional electric field extending through said medium in a direction transverse to the direction of travel of said charge carriers to decrease the density of said charge carriers.
References Cited (Backward Citations)
NL6812862A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-22 | 1976-02-21 | 1976-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-22 | 1980-02-21 | 1980-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-22 | 1984-02-21 | 1984-08-22 | $7700.00 | Window Closed / Lapsed |