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:
Dec. 16, 1997
Filed:
Sep. 06, 1995
Mitsuhiro Tanaka, Chita-Gun, JP;
Masao Takeuchi, Natori, JP;
Kazuhiko Yamanouchi, Sendai, JP;
Hiroyuki Odagawa, Sendai, JP;
NGK Insulators, Ltd., , JP;
Abstract
A surface acoustic wave device including a substrate made of a lithium tetraborate single crystal (Li.sub.2 B.sub.4 O.sub.7) whose cut and propagating direction are determined such that Euler cut angles (.psi., .theta., .phi.) are .psi.=+5.degree..about.-5.degree., .theta.=9.degree..about.29.degree. and 32.degree..about.86.degree. and .phi.=85.degree..about.95.degree., and an electrode structure formed on a surface of the substrate to realize a natural single-phase unidirectional transducer property together with an anisotropy of said substrate. A lithium tetraborate substrate having cut angles of (0.degree., 51.degree., 90.degree.) shows an ideal NSPUDT and a lithium tetraborate substrate having cut angles of (0.degree., 78.degree., 90.degree.) reveals a zero temperature coefficient of delay. A directionality reversed electrode structure or a directionality corrected electrode structure may be advantageously used.