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. 16, 2004
Filed:
Jan. 14, 2002
Norio Taniguchi, Shiga-ken, JP;
Murata Manufacturing Co., Ltd., Kyoto, JP;
Abstract
A ladder circuit type SAW filter device includes series arm resonators and parallel arm resonators that are defined by SAW resonators. Among the parallel arm resonators, a first parallel arm resonator that is connected to one of an input end and an output end and a second parallel arm resonator that is connected to a junction between two series arm resonators have the relationship of Cp ×2<Cp , where Cp represents the capacitance of the first parallel arm resonator and Cp represents the capacitance of the second parallel arm resonator. The inductance of an inductor that is connected to the second parallel arm resonator is equal to or less than the inductance of the inductor that is connected to the first parallel arm resonator. The SAW filter device has superior steepness of filter characteristics in the lower range of a pass band and outstanding attenuation in a stop band.