Title:
FILTER DEVICE
Document Type and Number:
WIPO Patent Application WO/2016/208446
Kind Code:
A1
Abstract:
Provided is a filter device with which transverse mode ripple can be suppressed, insertion loss degradation is inhibited, and an increase in the Q value can be attained. The filter device 1 is provided with: a longitudinally coupled resonator acoustic wave filter 11, which has a plurality of first IDT electrodes 31-39 having a low-acoustic-velocity region on the outside of the center region of the IDT electrodes and a high-acoustic-velocity region on the outside of the low-acoustic-velocity region in the direction orthogonal to the acoustic wave propagation direction, and which functions as a first bandpass filter 5; and acoustic wave resonators 21, 22 electrically connected to the longitudinally coupled resonator acoustic wave filter 11. The acoustic wave resonators 21, 22 have a piezoelectric film comprising LiTaO3, and a high-acoustic-velocity member in which the acoustic velocity of a bulk wave propagating therethrough is higher than the acoustic velocity of an acoustic wave propagating through the piezoelectric film. The piezoelectric film is laminated directly or indirectly on the high-acoustic-velocity member. The IDT electrodes 31-39 are connected by longitudinal coupling on one surface of the piezoelectric film. A second IDT electrode is provided on one surface of the piezoelectric film. The direction linking the tips of a plurality of first electrode fingers and the direction linking the tips of a plurality of second electrode fingers of the second IDT electrode form a tilt angle ν (where ν is a positive value exceeding 0°) in relation to the acoustic wave propagation angle ψ defined by the Euler angles (φ, θ, ψ) of LiTaO3.
Inventors:
IWAMOTO HIDEKI (JP)
OKADA KEIJI (JP)
TAKAMINE YUICHI (JP)
TAKAI TSUTOMU (JP)
OKADA KEIJI (JP)
TAKAMINE YUICHI (JP)
TAKAI TSUTOMU (JP)
Application Number:
PCT/JP2016/067572
Publication Date:
December 29, 2016
Filing Date:
June 13, 2016
Export Citation:
Assignee:
MURATA MANUFACTURING CO (JP)
International Classes:
H03H9/145; H03H9/72
Domestic Patent References:
| WO2014196245A1 | 2014-12-11 | |||
| WO2012086639A1 | 2012-06-28 |
Foreign References:
| JP2011182220A | 2011-09-15 | |||
| JP2013544041A | 2013-12-09 |
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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