The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 06, 2002
Filed:
Aug. 16, 2000
Kenji Inoue, Tokyo, JP;
Katsuo Sato, Tokyo, JP;
Hiroki Morikoshi, Tokyo, JP;
Katsumi Kawasaki, Tokyo, JP;
Kiyoshi Uchida, Tokyo, JP;
TDK Corporation, Tokyo, JP;
Abstract
A surface acoustic wave device includes a substrate and an inter-digital electrode on a surface of the substrate, wherein the substrate is formed by cutting out of a single crystal represented by a chemical formula, La&agr;Ta&bgr;Ga&ggr;O&dgr;(2.9≦&agr;≦3.1, 0.48≦&bgr;≦0.52, 5.4≦&ggr;≦5.6 and 8≦&dgr;≦14); a cut angle of the substrate cut out of the single crystal and a direction of propagation of surface acoustic waves on the substrate represented in terms of Euler's angles (&phgr;, &thgr;, &psgr;), &phgr;, &thgr; and &psgr; are found in one of a first area represented by −5 degrees≦&phgr;≦−5 degrees, 135 degrees≦&thgr;≦150 degrees and 20 degrees<&psgr;<25 degrees, and a second area represented by −5 degrees≦&phgr;≦−5 degrees, 135 degrees≦&thgr;≦150 degrees and −25 degrees≦&psgr;≦−20 degrees, respectively; and a normalized thickness h/&lgr; obtained by normalizing a thickness h of the inter-digital electrode finger with a wavelength of the surface acoustic wave exceeds 0.5% and is equal to or smaller than 4%. The thus constituted surface acoustic wave device enables miniaturization, band-widening and excellent selectivity, namely, superior temperature characteristics.