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. 01, 1995
Filed:
Jul. 01, 1993
Applicant:
Inventors:
Assignees:
Other;
NGK Insulators, Ltd., both of, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03H / ;
U.S. Cl.
CPC ...
333195 ; 333194 ; 3103 / ;
Abstract
A surface acoustic wave filter device includes a substrate which includes quartz or the like piezoelectric material having a small temperature coefficient. The substrate has a surface which is formed with interdigital-type unidirectional transducers on input and output sides, each having a positive electrode and a negative electrode. The positive electrodes and the negative electrodes of each of the input side and output side transducers have electrode fingers which are arranged so as to transduce a harmonic wave of a selected order which is higher relative to a fundamental surface acoustic wave.