SAW filter operable in a piston mode
US7576471B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 28, 2007 |
| Grant date | Aug 18, 2009 |
| Priority date | — |
| Expiry date | Sep 28, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/6496
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A SAW transducer includes a pair of opposing bus bars formed on a surface of a piezoelectric substrate with a plurality of interdigital electrodes extending from each of the opposing bus bars. A center region and opposing edge regions are formed, wherein each edge region is proximate each bus bar and includes free end portions of the electrodes such that a wave velocity in each edge region is substantially lower than a wave velocity in the bus bars and in the center region, and wherein electro-acoustic sources extend into the edge regions for providing a SAW transducer having the piezoelectrically excited strongest mode is a piston mode with an amplitude distribution generally flat across most of the resonator area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.