Surface acoustic wave devices using surface acoustic waves with strong piezoelectric coupling
US7446453B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 3, 2007 |
| Grant date | Nov 4, 2008 |
| Priority date | — |
| Expiry date | Jul 3, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/14538
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A SAW device includes a LiNbO3 single crystal piezoelectric substrate having an orientation defined by Euler angles (λ,μ,θ), with angle λ ranging from −5° to +5°, angle μ ranging from about −74° to about −65°, and angle θ ranging from −5° to +5°. Electrode patterns on a surface of the substrate form element resonators having a metallization ratio ranging from about 0.3 to about 0.8 and electrode thicknesses ranging from about 12% to about 17.5% of an acoustic wavelength of a strongly coupled non-leaky surface acoustic wave, excited on the surface of the substrate, if Al is used as electrode material, and in a range from about 6% to about 10% of an acoustic wavelength, if Cu is used as electrode material. Such orientations simultaneously combined with an optimized electromechanical coupling of spurious surface acoustic mode provide for improved performance in RF applications with a widened passband.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.