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:
Nov. 12, 2002
Filed:
Mar. 30, 2000
Masayuki Fujita, Kyoto, JP;
Toshiharu Tanaka, Kadoma, JP;
Other;
Abstract
The invention provides a three-stage surface acoustic wave filter of the ladder type wherein the resonance frequency difference &Dgr;f between the resonance frequency f of a serial resonator in an intermediate stage and the resonance frequency f of a parallel resonator therein is set at a value greater than the resonance frequency difference &Dgr;f (&Dgr;f ) between the resonance frequency f (f ) of a serial resonator in each of front and rear stages and the resonance frequency f (f ) of a parallel resonator therein, whereby the filter is given a widened pass band while reliably retaining satisfactory characteristics comparable to those of conventional surface acoustic wave filters of small pass band width. The desired filter exhibiting such performance is available within a shorter period of time and with reduced labor.