Invention Grant
- Patent Title: Band rejection filter
- Patent Title (中): 带阻滤波器
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Application No.: US12978673Application Date: 2010-12-27
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Publication No.: US08773221B2Publication Date: 2014-07-08
- Inventor: Norihiko Nakahashi , Yasumasa Taniguchi
- Applicant: Norihiko Nakahashi , Yasumasa Taniguchi
- Applicant Address: JP Kyoto
- Assignee: Murata Manufacturing Co., Ltd.
- Current Assignee: Murata Manufacturing Co., Ltd.
- Current Assignee Address: JP Kyoto
- Agency: Keating & Bennett, LLP
- Priority: JP2008-170565 20080630
- Main IPC: H03H9/64
- IPC: H03H9/64 ; H03H9/145 ; H03H7/01

Abstract:
An inexpensive compact band rejection filter realizes a high sharpness of a filter characteristic at ends of passbands and has a large attenuation. In the band rejection filter, at least one of a plurality of elastic wave resonators, which contributes to formation of a transition band, has a propagation angle larger than those of the other elastic wave resonators. Accordingly, the at least one of the plurality of elastic wave resonators which contributes to the formation of the transition band has an electromechanical coupling coefficient that is smaller than electromechanical coupling coefficients of the other elastic wave resonators.
Public/Granted literature
- US20110090026A1 BAND REJECTION FILTER Public/Granted day:2011-04-21
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