Title:
ELASTIC WAVE DEVICE, MULTIPLEXER, HIGH-FREQUENCY FRONT END CIRCUIT, AND COMMUNICATION DEVICE
Document Type and Number:
WIPO Patent Application WO/2019/138813
Kind Code:
A1
Abstract:
This elastic wave device reduces spurious Rayleigh waves generated in frequencies below the passband while suppressing characteristic degradation of the passband. In this elastic wave device (1), an antenna terminal resonator electrically nearest to a first terminal (101) is a first elastic wave resonator (3A). In each of the first elastic wave resonator (3A) and a second elastic wave resonator (3B), the thickness of a piezoelectric layer is less than or equal to 3.5λ, with λ defined as the wavelength of the elastic wave. The cut angle of the piezoelectric layer of the first elastic wave resonator (3A) is within the range θB±4°, based on θB(°), from the wavelength, the IDT electrode thickness, the IDT electrode specific gravity, the duty ratio, which is the value obtained by dividing the width of electrode fingers by half of the electrode finger period, the piezoelectric layer thickness, and the thickness of a low sound velocity membrane. The difference between θB(°) and the cut angle of the piezoelectric layer of the second elastic wave resonator (3B), which is at least one of the elastic wave resonators other than the first elastic wave resonator (3A), is greater than the difference between θB(°) and the cut angle of the piezoelectric layer of the first elastic wave resonator (3A).
Inventors:
NAKAGAWA RYO
IWAMOTO HIDEKI
TAKAI TSUTOMU
TAKAMINE YUICHI
IWAMOTO HIDEKI
TAKAI TSUTOMU
TAKAMINE YUICHI
Application Number:
PCT/JP2018/046700
Publication Date:
July 18, 2019
Filing Date:
December 19, 2018
Export Citation:
Assignee:
MURATA MANUFACTURING CO (JP)
International Classes:
H03H9/145; H03H9/25; H03H9/64; H03H9/72
Domestic Patent References:
| WO2016208446A1 | 2016-12-29 | |||
| WO2010131737A1 | 2010-11-18 | |||
| WO2017006742A1 | 2017-01-12 |
Foreign References:
| JP2017147674A | 2017-08-24 | |||
| JP2012151697A | 2012-08-09 | |||
| JP2003142984A | 2003-05-16 |
Attorney, Agent or Firm:
HOKUTO PATENT ATTORNEYS OFFICE (JP)
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