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:
Mar. 15, 1994
Filed:
Mar. 26, 1993
Kazuhiko Yamanouchi, Sendai, City, Miyagi Pref., JP;
Mitsuhiro Tanaka, Chita, JP;
Masahiko Sugiyama, Nagoya, JP;
Yasufumi Horio, Nagoya, JP;
Masatsugu Oshima, Nagoya, JP;
Kenji Suzuki, Nagoya, JP;
Other;
NGK Insulators, Ltd., , JP;
Abstract
A surface acoustic wave filter device includes a substrate which comprises quartz or the like piezoelectric having a small temperature coefficient and which is formed with unidirectional transducers of asymmetrical construction. A floating electrode is spaced from intermediate position between adjacent positive and negative electrodes which are arranged in interdigital manner, to effectively utilize a mechanical reflection caused by the floating electrode. In consideration of the sign and magnitude of the reflection factor of the floating electrodes, short-circuited electrodes only are used for the floating electrodes. The surface acoustic wave filter device has improved temperature characteristic, insertion loss characteristic and phase characteristic.