Acoustic wave device with multi-layer piezoelectric substrate
AssigneeSkyworks Solutions, Inc.
InventorsHiroyuki Nakamura, Rei Goto, Keiichi Maki
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Abstract
Aspects of this disclosure relate to an acoustic wave device that includes high velocity layers on opposing sides of a piezoelectric layer. A low velocity layer can be positioned between the piezoelectric layer and one of the high velocity layers, in which the low velocity layer has a lower acoustic velocity than the high velocity layers. The acoustic wave device can be configured to generate a boundary acoustic wave such that acoustic energy is concentrated at a boundary of the piezoelectric layer and the low velocity layer.
Claims20
An acoustic wave device comprising:
- a piezoelectric layer;
- an interdigital transducer electrode on the piezoelectric layer;
- high velocity layers on opposing sides of the piezoelectric layer;
- and
- a low velocity layer positioned between the piezoelectric layer and a first high velocity layer of the high velocity layers, the low velocity layer having a lower acoustic velocity than the high velocity layers, the acoustic velocity of the low velocity layer being a speed of sound of a shear wave propagating in the low velocity layer, the acoustic wave device having a combined thickness in a range from 10 micrometers to 100 micrometers, the combined thickness including thicknesses of the piezoelectric layer and the high velocity layers and the low velocity layer, and the acoustic wave device being configured to generate a boundary acoustic wave such that acoustic energy is concentrated at a boundary of the piezoelectric layer and the low velocity layer.
A radio frequency module comprising:
- an acoustic wave filter configured to filter a radio frequency signal, the acoustic wave filter including an acoustic wave device including a piezoelectric layer, an interdigital transducer electrode on the piezoelectric layer, high velocity layers on opposing sides of the piezoelectric layer, and a low velocity layer disposed between the piezoelectric layer and a first high velocity layer of the high velocity layers, the low velocity layer having a lower acoustic velocity than the high velocity layers, the acoustic wave device having a combined thickness in a range from 10 micrometers to 100 micrometers, the combined thickness including thicknesses of the piezoelectric layer and the high velocity layers and the low velocity layer, and the acoustic wave device being configured to generate a boundary acoustic wave such that acoustic energy is concentrated at a boundary of the piezoelectric layer and the low velocity layer;
- and
- a radio frequency switch coupled to the acoustic wave filter, the radio frequency switch being packaged with the acoustic wave filter.
A method of filtering a radio frequency signal with an acoustic wave filter, the method comprising:
- providing a radio frequency signal to an acoustic wave filter;
- and
- filtering the radio frequency signal with the acoustic wave filter, the acoustic wave filter including an acoustic wave device that includes a piezoelectric layer, an interdigital transducer electrode on the piezoelectric layer, high velocity layers on opposing sides of the piezoelectric layer, a low velocity layer positioned between the piezoelectric layer and a first high velocity layer of the high velocity layers, the low velocity layer having a lower acoustic velocity than the high velocity layers, the acoustic wave device having a combined thickness in a range from 10 micrometers to 100 micrometers, the combined thickness including thicknesses of the piezoelectric layer and the high velocity layers and the low velocity layer, and the acoustic wave device generating a boundary acoustic wave such that acoustic energy is concentrated at a boundary of the piezoelectric layer and the low velocity layer.
Dependencies are inferred from the claim text.