Filter system comprising a bulk acoustic wave resonator
The invention relates to a filter device equipped with at least one bulk acoustic wave resonator, which comprises a resonator unit and a reflection element ( 2 ) comprising several layers ( 6, 7, 8 ). The layers ( 6, 7, 8 ) each comprise a mixture of at least two materials. Within each layer ( 6, 7, 8 ), the composition of the mixture varies continuously and periodically relative to the layer thickness.
1. A filter device equipped with at least one bulk acoustic wave resonator, which comprises a resonator unit and a reflection element ( 2 ), wherein the reflection element ( 2 ) comprises several layers ( 6 , 7 , 8 ), which each comprise a mixture of at least two materials, wherein, within each layer ( 6 , 7 , 8 ), the composition of the mixture varies continuously and periodically relative to the layer thickness.
2. A filter device as claimed in claim 1 , characterized in that the reflection element ( 2 ) comprises a mixture of SiO 2 and Ta 2 O 5 or SiO 2 and Si 3 N 4 .
3. A mobile radio device equipped with a filter device with at least one bulk acoustic wave resonator, which comprises a resonator unit and a reflection element ( 2 ), wherein the reflection element ( 2 ) comprises several layers ( 6 , 7 , 8 ), which each comprise a mixture of at least two materials, wherein, within each layer ( 6 , 7 , 8 ), the composition of the mixture varies continuously and periodically relative to the layer thickness.
4. A transmitter equipped with a filter device with at least one bulk acoustic wave resonator, which comprises a resonator unit and a reflection element ( 2 ), wherein the reflector element ( 2 ) comprises several layers ( 6 , 7 , 8 ), which each comprise a mixture of at least two materials, wherein, within each layer ( 6 , 7 , 8 ), the composition of the mixture varies continuously and periodically relative to the layer thickness.
5. A receiver equipped with a filter device with at least one bulk acoustic wave resonator, which comprises a resonator unit and a reflection element ( 2 ), wherein the reflection element ( 2 ) comprises several layers ( 6 , 7 , 8 ), which each comprise a mixture of at least two materials, wherein, within each layer ( 6 , 7 , 8 ), the composition of the mixture varies continuously and periodically relative to the layer thickness.
6. A wireless data transmission system equipped with a filter device with at least one bulk acoustic wave resonator, which comprises a resonator unit and a reflection element ( 2 ), wherein the reflector element ( 2 ) comprises multiple layers ( 6 , 7 , 8 ), which each comprise a mixture of at least two materials, wherein, within each layer ( 6 , 7 , 8 ), the composition of the mixture varies continuously and periodically relative to the layer thickness.
7. A bulk acoustic wave resonator, which comprises a resonator unit and a reflection element ( 2 ), wherein the reflection element ( 2 ) comprises several layers ( 6 , 7 , 8 ), which each comprise a mixture of at least two materials, wherein, within each layer ( 6 , 7 , 8 ), the composition of the mixture varies continuously and periodically relative to the layer thickness.