Invention Grant
- Patent Title: Branching filter
- Patent Title (中): 分支过滤器
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Application No.: US13487432Application Date: 2012-06-04
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Publication No.: US08416036B2Publication Date: 2013-04-09
- Inventor: Toshiaki Takata , Yasuhiro Shimizu
- Applicant: Toshiaki Takata , Yasuhiro Shimizu
- 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: JP2009-294653 20091225
- Main IPC: H03H9/72
- IPC: H03H9/72 ; H03H9/64

Abstract:
A branching filter includes a longitudinally-coupled-resonator-type elastic wave filter having a balanced-unbalanced transformation function and the branching filter has excellent balance characteristics and a small size. The branching filter includes a ladder elastic wave filter chip and a longitudinally-coupled-resonator-type elastic wave filter chip. An antenna back-surface electrode and an antenna electrode pad are connected to each other via a first wiring provided in a wiring substrate. The antenna electrode pad and a longitudinally-coupled-resonator-type elastic wave filter are connected to each other via a second wiring provided on a piezoelectric substrate. The second wiring extends in a first direction and a first functional electrode and a second functional electrode provided on the piezoelectric substrate are axisymmetrically arranged with respect to each other about a central axis that extends in the first direction of the second wiring.
Public/Granted literature
- US20120235767A1 BRANCHING FILTER Public/Granted day:2012-09-20
Information query
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