US3821667A
Expired / Lapsed
US
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Process and apparatus for the production of propagating electric alternating fields
Assignee: Siemens AG
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Filing: 1973-05-24
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Granted: 1974-06-28
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Expires: 1993-05-24
Abstract
Abstract Propagating electric alternating fields are produced in a piezoelectric body in which an acoustic wave is coupled in by means of a transducer, the piezoelectric body having a permanently aligned surface polarization which is periodic in one region of its surface. The polarization is provided by the application of appropriate potentials to polarization electrodes in the form of interdigital electrodes which are temporarily applied to the body and subsequently removed, for example by etching. An acoustic wave having a wave length in the order of magnitude of the period of polarization of the surface polarization is coupled in and electric field components with differing phase velocities are produced in the region of the surface polarization in the space above the surface of the piezoelectric body, the phase velocity of one field component being considerably less than the phase velocity of the other field component. In one embodiment a piezoelectric ceramic body has an electromechanical transducer which serves for output coupling of acoustic waves and a semiconductor body is provided above the surface of the piezoelectric ceramic body in the region of the periodic permanent surface polarization for purpose of amplification. In another embodiment, two piezoelectric ceramic bodies having equal, permanently aligned, periodic surface polarization and each having an electromechanical transducer, are arranged in an overlapping close proximity relationship as an adjustable time delay device.
Inventors
- 👤 H Thomann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:17
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/02535; H03H9/0296; H03H9/02976; H03F; H03F13/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
125 words
A method of producing propagating electric alternating fields in a piezoelectric body, comprising the steps of: temporarily applying polarization electrodes to a surface of the body in a pattern which will produce periodic aligned surface polarization; energizing the electrodes to provide a permanent, aligned, periodic surface polarization of the piezoElectric body; and connecting a transducer to the surface of the body for coupling in an acoustic wave having a wave length in the order of magnitude of the period of polarization which produces electric field components having differing phase velocities in the region of the surface polarization in the space above the surface of the piezoelectric body, the phase velocity of one field component being considerably lower than the phase velocity of another field component.
Claim 2
Independent Claim
125 words
A method of producing propagating electric alternating fields in a piezoelectric body, comprising the steps of: temporarily applying polarization electrodes to a surface of the body in a pattern which will produce periodic aligned surface polarization; energizing the electrodes to provide a permanent, aligned, periodic surface polarization of the piezoElectric body; and connecting a transducer to the surface of the body for coupling in an acoustic wave having a wave length in the order of magnitude of the period of polarization which produces electric field components having differing phase velocities in the region of the surface polarization in the space above the surface of the piezoelectric body, the phase velocity of one field component being considerably lower than the phase velocity of another field component.
Claim 3
Dependent Claim
63 words
The method set forth in claim 1, wherein the step of temporarily applying polarization electrodes is further defined as: applying to the surface a pair of interdigital electrodes each having fingers extending between adjacent fingers of the other interdigital electrode; and removing the interdigital electrodes from the surface of the piezoelectric body after the electrodes have been energized to provide the permanent polarization.
Claim 4
Dependent Claim
122 words
A surface wave traveling wave amplifier, comprising: a piezoelectric body including a surface having at least a portion thereof polarized with a permanent, aligned, periodic surface polarization; a pair of electromechanical transducers mounted on said surface on respective sides of said polarized portion; and a semiconductor body in close proximity to said polarized portion of said surface, an acoustic surface wave coupled into said body by one of said transducers effecting electric alternating fields having field components of different phase velocities above said polarized portion of said surface, the slower field component being coupled into said semiconductor body, amplified by the charge carriers of said semiconductor body and coupled back to said piezoelectric body to be coupled out by the other transducer.
Claim 5
Dependent Claim
122 words
A surface wave traveling wave amplifier, comprising: a piezoelectric body including a surface having at least a portion thereof polarized with a permanent, aligned, periodic surface polarization; a pair of electromechanical transducers mounted on said surface on respective sides of said polarized portion; and a semiconductor body in close proximity to said polarized portion of said surface, an acoustic surface wave coupled into said body by one of said transducers effecting electric alternating fields having field components of different phase velocities above said polarized portion of said surface, the slower field component being coupled into said semiconductor body, amplified by the charge carriers of said semiconductor body and coupled back to said piezoelectric body to be coupled out by the other transducer.
Claim 6
Dependent Claim
28 words
A surface wave traveling wave amplifier as set forth in claim 3 comprising a liquid with a high dielectric constant between said piezoelectric body and said semiconductor body.
Claim 7
Dependent Claim
122 words
A delay line comprising: first and second piezoelectric bodies each having a surface which is polarized with a permanent, aligned, periodic surface polarization, said polarized surfaces facing each other with said bodies positioned in an overlapping relationship; an input transducer carried on said polarized surface of said first piezoelectric body for coupling in an acoustic surface wave to effect electric alternating fields traversing said surface and having field components of different phase velocities, said field components coupled to said second body in the region of overlap of said bodies; and an output transducer carried on the polarized surface of said second body for coupling out an output in response to the field components coupled from said first body to said second body.
Claim 8
Dependent Claim
122 words
A delay line comprising: first and second piezoelectric bodies each having a surface which is polarized with a permanent, aligned, periodic surface polarization, said polarized surfaces facing each other with said bodies positioned in an overlapping relationship; an input transducer carried on said polarized surface of said first piezoelectric body for coupling in an acoustic surface wave to effect electric alternating fields traversing said surface and having field components of different phase velocities, said field components coupled to said second body in the region of overlap of said bodies; and an output transducer carried on the polarized surface of said second body for coupling out an output in response to the field components coupled from said first body to said second body.
Claim 9
Dependent Claim
24 words
A delay line as set forth in claim 5, wherein said bodies are displaceable relative to one another to provide an adjustable delay line.
Claim 10
Dependent Claim
20 words
The delay line according to claim 5, comprising a high dielectric constant liquid between the overlapping portions of said bodies.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |