Patent US4879487A successfully refreshed from Google Patents.
US4879487A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surface-acoustic-wave device
Assignee: Faurecia Clarion Electronics Co Ltd
•
Filing: 1988-05-19
•
Granted: 1989-11-07
•
Expires: 2008-05-19
Abstract
Abstract A surface-acoustic-wave device includes a glassy layer provided on a piezoelectric layer and having periodic grooves (gratings) so as to be used as a reflector exhibiting an excellent reflection ratio.
Inventors
- 👤 Kazuyoshi Sugai
- 👤 Kiyotaka Sato
- 👤 Hiroshi Nishizato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:51
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/02535; H03H9/02543; H03H9/02574; H03H9/02637; H03H9/02653
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
83 words
A surface-acoustic-wave device comprising: a semiconductor substrate; a piezoelectric layer provided on one surface of said semi-conductor substrate; a glassy layer provided on one surface of said piezoelectric layer on a side of said piezoelectric layer remote from said substrate; and a plurality of grooves which are spaced periodically and which are provided in a surface of said glassy layer located on a side thereof remote from said piezoelectric layer, said grooves extending transversely with respect to a surface acoustic wave travelling direction.
Claim 2
Dependent Claim
83 words
A surface-acoustic-wave device comprising: a semiconductor substrate; a piezoelectric layer provided on one surface of said semi-conductor substrate; a glassy layer provided on one surface of said piezoelectric layer on a side of said piezoelectric layer remote from said substrate; and a plurality of grooves which are spaced periodically and which are provided in a surface of said glassy layer located on a side thereof remote from said piezoelectric layer, said grooves extending transversely with respect to a surface acoustic wave travelling direction.
Claim 3
Dependent Claim
49 words
A surface-acoustic-wave device according to claim 1 wherein said semiconductor substrate is made from silicon single crystal, said piezoelectric layer is made from aluminum nitride (AlN), and said glassy layer is made from SiO 2 , phosphoric silicic acid glass, boron silicic acid glass or boron-phosphoric silicic acid glass.
Claim 4
Dependent Claim
31 words
A surface acoustic wave device according to claim 1 wherein said glassy layer has a thickness H with respect to the wavelength λ of a surface acoustic wave which satisfies: 2πH/λ>0.1
Claim 5
Dependent Claim
94 words
A surface acoustic wave device comprising: a semiconductor substrate; a piezoelectric layer provided on one surface of said semi-conductor substrate; a glassy layer provided on one surface of said piezoelectric layer on a side of said piezoelectric layer remote from said substrate; electrode means provided on said one surface of said piezoelectric layer for producing an detecting a surface acoustic wave; and two arrays of grooves provided on one surface of said glassy layer on a side thereof remote from said piezoelectric layer at spaced positions located on opposite sides of said electrode means.
Claim 6
Dependent Claim
94 words
A surface acoustic wave device comprising: a semiconductor substrate; a piezoelectric layer provided on one surface of said semi-conductor substrate; a glassy layer provided on one surface of said piezoelectric layer on a side of said piezoelectric layer remote from said substrate; electrode means provided on said one surface of said piezoelectric layer for producing an detecting a surface acoustic wave; and two arrays of grooves provided on one surface of said glassy layer on a side thereof remote from said piezoelectric layer at spaced positions located on opposite sides of said electrode means.
Claim 7
Dependent Claim
39 words
A surface acoustic wave device according to claim 4 wherein the distance Lc between opposed ends of each said electrode and each said array of grooves is Lc≈(5/8)λ with respect to the wavelength λ of a surface acoustic wave.
Claim 8
Dependent Claim
16 words
A surface acoustic wave according to claim 4 wherein said piezoelectric layer is made from AlN.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-11-06 | 1993-05-08 | 1993-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-06 | 1997-05-08 | 1997-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-06 | 2001-05-08 | 2001-11-07 | $7700.00 | Window Closed / Lapsed |