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. 29, 1988
Filed:
Mar. 26, 1986
Hitachi, Ltd., both of, JP;
Hitachi Denshi Kabushiki, both of, JP;
Abstract
In order to realize an SAW filter withstanding high power, a plurality of single open-ended surface acoustic wave resonators are connected in series, and an earth conductor is disposed at least on a part of rear face of a piezoelectric substrate constituting the surface acoustic wave resonators. And static capacities formed between said earth conductor and electrode conductors on the piezoelectric substrate constituting the surface acoustic wave resonators are utilized as constituents of the filter circuit. In the above described structure, a part of input power is not converted into acoustic energy, but directly transmitted to the output side. Since the mechanical stress imposed upon the electrode material and the piezoelectric substrate is thus lightened, the SAW filter can withstand a large power signal.