Title:
LADDER FILTER AND DUPLEXER
Document Type and Number:
WIPO Patent Application WO/2016/031391
Kind Code:
A1
Abstract:
This invention provides a ladder filter that can sufficiently attenuate a signal in a frequency band near the passband of the ladder filter on the low-frequency side of said passband. Said ladder filter 1 contains a plurality of series-arm resonators S1-S3 and three or more parallel-arm resonators P1, P21, P22, P3 provided respectively in three or more parallel arms. At least the parallel-arm resonator the farthest from an input terminal (transmission terminal 3) and an output terminal (common connection terminal 5) is divided into first and second sub-resonators P21, P22 in parallel with each other. The second sub-resonator P22 has the highest resonant frequency and the lowest capacitance of all of the parallel-arm resonators, including all sub-resonators.
Inventors:
TAKAMINE YUICHI (JP)
Application Number:
PCT/JP2015/069180
Publication Date:
March 03, 2016
Filing Date:
July 02, 2015
Export Citation:
Assignee:
MURATA MANUFACTURING CO (JP)
International Classes:
H03H9/64; H03H9/72
Domestic Patent References:
| WO2013080461A1 | 2013-06-06 |
Attorney, Agent or Firm:
MIYAZAKI & METSUGI (JP)
Patent business corporation Miyazaki and table-of-contents patent firm (JP)
Patent business corporation Miyazaki and table-of-contents patent firm (JP)
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