Acoustic wave element, duplexer and communication device
US9978927B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 29, 2014 |
| Grant date | May 22, 2018 |
| Priority date | — |
| Expiry date | Jun 7, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/0038
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An elastic wave element has a piezoelectric substrate; an excitation electrode which is located on an upper surface of the piezoelectric substrate and generates an acoustic wave, and two reflectors which are located on the upper surface of the piezoelectric substrate and sandwich the excitation electrode in the propagation direction of the acoustic wave. The excitation electrode has a main region located between the two end parts of the propagation direction and outer regions located on two sides of the main region. When the number of the electrode fingers of the outer region is “m”, an electrode finger interval of the main region is “a”, and an interval between the electrode finger of the main region on the outer region side and the reflector electrode finger of the reflector is “x”, 0.5×a×(m+1)<x<a×(m+1) is satisfied. Further, a resonant frequency of the reflector is lower than a resonant frequency in the main region of the excitation electrode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.