Thin-film bulk acoustic resonator with enhanced power handling capacity
US6515558B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 6, 2000 |
| Grant date | Feb 4, 2003 |
| Priority date | — |
| Expiry date | Nov 6, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/02133
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A filter and a method for fabricating a filter comprising a thin film bulk acoustic wave resonator (FBAR), the FBAR including a plurality of layers of different materials deposited on top of each other and oh top of a substrate, the FBAR including a piezolayer sandwiched between a top electrode on the side of the piezolayer facing away from the substrate, and a bottom electrode on the side of the piezolayer facing the substrate, the FBAR further including an acoustic mirror made from a number of layers of different materials selected to provide in combination high reflectivity of sound energy, the method comprising the step of forming the bottom electrode from a material having a small acoustic impedance. A filter fabricated according to the method is advantageously used as part of a mobile phone, in the transmitter/receiver section of the mobile phone, the transmitter section including a power amplifier used to amplify signals before transmitting the signals via an antenna, and in particular as a component of a transmitter filter, coupling the power amplifier of the transmitter section to the antenna.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.