Title:
ACOUSTIC WAVE FILTER DEVICE
Document Type and Number:
WIPO Patent Application WO/2018/070273
Kind Code:
A1
Abstract:
Provided is an acoustic wave filter device which is capable of reducing ripples in a stopband on the high-frequency side of a passband of a bandpass filter, and with which deterioration due to an insertion loss of another bandpass filter commonly connected to the abovementioned bandpass filter can be suppressed.
This acoustic wave filter device is provided with: a first bandpass filter which has a first passband and includes a first acoustic wave resonator connected between an antenna terminal and a first signal terminal; and a second bandpass filter which is connected to the antenna terminal and has a second passband on the high-frequency side of the first passband. The first acoustic wave resonator includes: a base plate provided on a surface thereof with a piezoelectric thin film 7; an IDT electrode 5 provided on the base plate; and reflectors 6a, 6b. In at least one of the IDT electrode 5 and the reflectors 6a, 6b of the first acoustic wave resonator (series-arm resonator S5) disposed closest to the antenna terminal, an electrode finger pitch of at least a portion thereof is different from the electrode finger pitch of other parts.
Inventors:
TAKAMINE YUICHI (JP)
Application Number:
PCT/JP2017/035498
Publication Date:
April 19, 2018
Filing Date:
September 29, 2017
Export Citation:
Assignee:
MURATA MANUFACTURING CO (JP)
International Classes:
H03H9/72; H03H7/46; H03H9/145
Domestic Patent References:
| WO2010061496A1 | 2010-06-03 | |||
| WO2016017730A1 | 2016-02-04 |
Foreign References:
| JPH10163803A | 1998-06-19 | |||
| JP2005244669A | 2005-09-08 | |||
| JPH1041704A | 1998-02-13 |
Attorney, Agent or Firm:
MIYAZAKI & METSUGI (JP)
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