Elastic wave device, high-frequency front-end circuit, and communication apparatus
AssigneeMurata Manufacturing Co., Ltd.
InventorMasakazu MIMURA
Life of this patent
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Abstract
An elastic wave device includes a supporting substrate, an acoustic reflection layer disposed on the supporting substrate, a piezoelectric layer disposed on the acoustic reflection layer, and an interdigital transducer electrode disposed on the piezoelectric layer. The acoustic reflection layer includes three or more low acoustic impedance layers and two or more high acoustic impedance layers. A film thickness of the low acoustic impedance layer closest to the piezoelectric layer is larger than a film thickness of the low acoustic impedance layer closest to the low acoustic impedance layer that is closest to the piezoelectric layer.
Claims20
An elastic wave device comprising:
- a supporting substrate;
- an acoustic reflection layer disposed on the supporting substrate;
- a piezoelectric layer disposed on the acoustic reflection layer;
- and
- an interdigital transducer electrode disposed on the piezoelectric layer;
- wherein
- the acoustic reflection layer includes:
- three or more low acoustic impedance layers;
- and
- two or more high acoustic impedance layers;
- and
- a film thickness of a low acoustic impedance layer of the three or more low acoustic impedance layers closest to the piezoelectric layer is larger than a film thickness of a low acoustic impedance layer of the three or more low acoustic impedance layers closest to the low acoustic impedance layer that is closest to the piezoelectric layer.
Dependencies are inferred from the claim text.