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. 24, 2004
Filed:
Dec. 13, 2001
Naoki Tanaka, Sakai, JP;
Tatsuro Usuki, Osaka, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
In the surface acoustic wave filter, a longitudinally-coupled double-mode resonator filter formed by arranging a plurality of inter-digital transducers for exciting and receiving a surface acoustic wave adjacent each other in the direction of propagation of the surface acoustic wave is connected in series to a resonator having one or a plurality of inter-digital transducers for exciting and receiving a surface acoustic wave. A cutoff frequency on the high-frequency side of the pass band of the longitudinally-coupled double-mode resonator filter and the antiresonant frequency of the resonator are substantially equal. In the surface acoustic wave filter, the sharpness in the vicinity of the cutoff frequency on the high-frequency side of the pass band is high, sufficient attenuation can be obtained, and the input and output impedance matching state is good.