Title:
COMPOSITE FILTER DEVICE
Document Type and Number:
WIPO Patent Application WO/2023/002909
Kind Code:
A1
Abstract:
Provided is a composite filter device capable of reducing an insertion loss in a band pass filter and increasing an attenuation amount in the vicinity of a pass band. A composite filter device 10 comprises: a first band pass filter 1A that has a piezoelectric substrate 2 (lithium niobate substrate) and a plurality of resonators configured in the piezoelectric substrate 2, that is configured to be able to use a Rayleigh wave, and that has a first pass band; a second band pass filter 1B having a second pass band; and a common connection terminal 3. The first band pass filter 1A includes first and second longitudinal coupling resonator-type elastic wave filters 9A, 9B, and resonators other than the longitudinal coupling resonator-type elastic wave filters. The first and second longitudinal coupling resonator-type elastic wave filters 9A, 9B are arranged closest to the common connection terminal 3 side among the plurality of resonators. The second pass band includes a frequency within the range from f1L×1.2 to f1H×1.4, when f1L represents a frequency at the end of the first pass band on the low band side, and f1H represents a frequency at the end thereof on the high band side.
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Inventors:
ISHITAKI MASAYUKI (JP)
YASUDA JUNPEI (JP)
YASUDA JUNPEI (JP)
Application Number:
PCT/JP2022/027697
Publication Date:
January 26, 2023
Filing Date:
July 14, 2022
Export Citation:
Assignee:
MURATA MANUFACTURING CO (JP)
International Classes:
H03H9/72; H03H9/64
Domestic Patent References:
| WO2018116602A1 | 2018-06-28 | |||
| WO2017159409A1 | 2017-09-21 |
Foreign References:
| JP2017200171A | 2017-11-02 |
Attorney, Agent or Firm:
OSAKA FRONT (JP)
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