Piezoelectric filter, duplexer, composite piezoelectric resonator, communication device and method for adjusting frequency of piezoelectric filter
US7019604B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 2003 |
| Grant date | Mar 28, 2006 |
| Priority date | — |
| Expiry date | Jan 29, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2003/0471
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A piezoelectric filter and other electronic components are constructed such that the accuracy of frequency adjustment can be increased and an improvement in efficiency of the adjustment operation can be achieved. The piezoelectric filter includes a plurality of piezoelectric resonators including a substrate and a vibration portion provided on the substrate, the vibration portion having a structure in which the top and bottom surfaces of a thin film portion including at least one piezoelectric thin film are sandwiched between at least a pair of an upper electrode and a lower electrode facing each other, wherein the upper electrode of a predetermined piezoelectric resonator is made of a material having susceptibility to etching that is different from that of the upper electrode of the other piezoelectric resonator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.