Surface acoustic wave filter and multiplexer
US10778187B2 · kind B2 · utility
5Cited by
3References
20Claims
0Family size
Assignee
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Key dates
| Filing date | Apr 17, 2019 |
| Grant date | Sep 15, 2020 |
| Priority date | — |
| Expiry date | Apr 17, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/6483
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A filter includes a LiTaO3 piezoelectric layer having a cut angle, a high acoustic velocity support substrate, a low acoustic velocity film, and an IDT electrode. A cut angle θB of the piezoelectric layer at which a Rayleigh wave spurious response is locally reduced or minimized is determined from a wavelength of the IDT electrode, a film thickness of the IDT electrode, a specific gravity of the IDT electrode, an electrode duty, a thickness of the piezoelectric layer, and a film thickness of the low acoustic velocity film. The Cut angle of the piezoelectric layer satisfies a relationship of θB−4≤θ≤θB+4.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.