Filter and multiplexer
AssigneeMurata Manufacturing Co., Ltd.
InventorToshiaki Takata
Life of this patent
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Abstract
A filter includes a substrate including a piezoelectric layer, and first and second signal electrodes, a filter circuit on a first path connecting the first signal electrode and the second signal electrode, and an additional circuit on a second path connected in parallel with at least a portion of the first path. The filter circuit includes one or more resonators and a main wiring line on the substrate, and the additional circuit includes a sub-wiring line and an acoustically coupled resonator on the substrate, the acoustically coupled resonator including acoustic wave resonators adjacent to each other. An insulating film is between the substrate and the sub-wiring line. A dielectric constant of the insulating film is smaller than a dielectric constant of the piezoelectric layer.
Claims20
A filter, comprising:
- a substrate including a piezoelectric layer;
- a first signal electrode and a second signal electrode;
- a filter circuit on a first path connecting the first signal electrode and the second signal electrode;
- and
- an additional circuit on a second path connected in parallel with at least a portion of the first path;
- wherein
- the filter circuit includes one or more resonators and a main wiring line on the substrate;
- the additional circuit includes a sub-wiring line and an acoustically coupled resonator on the substrate, the acoustically coupled resonator including a plurality of acoustic wave resonators adjacent to each other;
- an insulating film is provided between the substrate and the sub-wiring line;
- and
- a dielectric constant of the insulating film is smaller than a dielectric constant of the piezoelectric layer.
A filter, comprising:
- a substrate including a piezoelectric layer;
- a first signal electrode and a second signal electrode;
- a filter circuit on a first path connecting the first signal electrode and the second signal electrode;
- and
- an additional circuit on a second path connected in parallel with at least a portion of the first path;
- wherein
- the filter circuit includes one or more resonators and a main wiring line on the substrate;
- the additional circuit includes a sub-wiring line and an acoustically coupled resonator on the substrate, the acoustically coupled resonator including a plurality of acoustic wave resonators adjacent to each other;
- an insulating film is provided between the substrate and the sub-wiring line;
- the insulating film includes, as a main component, at least one of silicon oxide, silicon nitride, silicon oxynitride, or polyimide or a combination thereof;
- and
- the piezoelectric layer includes lithium niobate or lithium tantalate.
Dependencies are inferred from the claim text.