Surface acoustic wave filter and method for improved rejection
US8031034B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 2, 2010 |
| Grant date | Oct 4, 2011 |
| Priority date | — |
| Expiry date | Sep 2, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/14588
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A SAW coupled resonator filter providing improved rejection outside the passband frequencies includes at least two filter tracks on a piezoelectric substrate with each track having a plurality of acoustically cascaded transducers disposed along a longitudinal axis of the filter track. At least one filter track includes signal pads driven in a differential mode or a balanced mode. The two tracks are electrically connected with crossover bridges crossing over connecting lines between the tracks such that voltages across the crossover bridges are approximately the same in magnitude but substantially out-of-phase. The connecting lines extend between opposing bus bars of split transducers within each of the filter tracks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.