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:
Feb. 17, 1998
Filed:
Apr. 09, 1996
Kuniyuki Matsui, Hirakata, JP;
Yasuhiro Hirao, Hirakata, JP;
Yasumi Kobayashi, Yawata, JP;
Kosuke Takeuchi, Hirakata, JP;
Kenichi Shibata, Hashimoto, JP;
Masami Ikeda, Osaka, JP;
Toshiharu Tanaka, Higashiosaka, JP;
Yasutaka Shimizu, Tokyo, JP;
Sanyo Electric Co., Ltd., Tokyo, JP;
Other;
Abstract
In a resonator-type surface acoustic wave filter comprising a lithium tantalate substrate, lithium niobate substrate or lithium tetraborate substrate having a cut plane of high velocity, the direction of propagation of surface acoustic waves is set within the range of (40 deg to 90 deg, 40 deg to 90 deg, 0 deg to 60 deg) as expressed in Eulerian angles, and the frequency difference .increment.f between the resonance frequency frs of series resonators and the resonance frequency frp of parallel resonators is set within a predetermined range formulated with the center frequency, the capacitance Cos of the series resonators and the capacitance Cop of the parallel resonators taken as parameters. Optimum ranges of the required design parameters are thus clarified to assure the resonator-type surface acoustic wave filter of higher performance.