Surface acoustic wave filter with optimized parallel and series resonator capacitances
US5719536A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Apr 9, 1996 |
| Grant date | Feb 17, 1998 |
| Priority date | — |
| Expiry date | Apr 9, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/02559
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In a resonator-type surface acoustic wave filter comprising a lithium tantalate substrate, lithium niobate substrate or lithium tetraborate substrate having a cut plane of high velocity, the direction of propagation of surface acoustic waves is set within the range of (40 deg to 90 deg, 40 deg to 90 deg, 0 deg to 60 deg) as expressed in Eulerian angles, and the capacitance Cos of the series resonators and the capacitance Cop of the parallel resonators are set within a predetermined range formulated with the center frequency taken as a parameter. Optimum ranges of the required design parameters are thus clarified to assure the resonator-type surface acoustic wave filter of higher performance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.