Title:
FILTER DEVICE
Document Type and Number:
WIPO Patent Application WO/2022/145385
Kind Code:
A1
Abstract:
Provided is a filter device less likely to experience deterioration in the amount of attenuation on a side having a higher frequency than the passband. A filter device 11 is provided with a first series arm resonator S11 provided to a series arm linking an input terminal 11a and an output terminal 11b, and a first parallel arm resonator P11 provided to a parallel arm comprising the series arm and a ground potential. The first series arm resonator S11 and the first parallel arm resonator P11 each have: an elastic wave resonator having a piezoelectric layer made of lithium niobate or lithium tantalate; and at least one pair of first electrodes and second electrodes provided over the piezoelectric layer, where d/p is 0.5 or less when d is the film thickness of the piezoelectric layer and p is the center-to-center distance of adjacent first and second electrodes. An inductor 12 is further provided in series with the first series arm resonator S11 between the first series arm resonator S11 and the first parallel arm resonator P11.
Inventors:
OUCHI MINEFUMI (JP)
Application Number:
PCT/JP2021/048304
Publication Date:
July 07, 2022
Filing Date:
December 24, 2021
Export Citation:
Assignee:
MURATA MANUFACTURING CO (JP)
International Classes:
H03H9/64
Domestic Patent References:
| WO2020095586A1 | 2020-05-14 |
Foreign References:
| JPH05183380A | 1993-07-23 | |||
| JP2015119452A | 2015-06-25 | |||
| JP2001326557A | 2001-11-22 | |||
| JP2004088143A | 2004-03-18 |
Attorney, Agent or Firm:
MIYAZAKI & METSUGI (JP)
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