Elastic wave device
AssigneeMurata Manufacturing Co., Ltd.
InventorsYutaka Kishimoto, Masashi Omura, Tetsuya Kimura
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Abstract
An elastic wave device includes an interdigital transducer electrode including electrode fingers provided on a first principal surface of a piezoelectric thin film. A conductive layer is provided on a second principal surface of the piezoelectric thin film. An elastic wave propagates in the piezoelectric thin film in an S0 mode of a plate wave, and a piezoelectric thin film portion in a region below spaces between the electrode fingers of the interdigital transducer electrode is displaced by a greater amount than each electrode finger and a piezoelectric thin film portion in a region below each electrode finger.
Claims19
An elastic wave device comprising:
- a piezoelectric thin film including a first principal surface and a second principal surface opposing the first principal surface;
- an interdigital transducer electrode provided on the first principal surface of the piezoelectric thin film and including a plurality of electrode fingers;
- and
- a conductive layer provided on the second principal surface of the piezoelectric thin film;
- wherein
- an elastic wave propagating in the piezoelectric thin film is an S0 mode of a plate wave;
- a piezoelectric thin film portion in a region below spaces between the electrode fingers of the interdigital transducer electrode is displaced by a greater amount than each electrode finger and a piezoelectric thin film portion in a region below each electrode finger;
- and
- in Euler Angles (φ, θ, ψ) of the piezoelectric thin film, φ is within a range of about 0°±20°, θ is within a range of not less than about 75° and not greater than about 145°, and ψ is within a range of about 0°±10°.
An elastic wave device comprising:
- a piezoelectric thin film including a first principal surface and a second principal surface opposing the first principal surface;
- an interdigital transducer electrode provided on the first principal surface of the piezoelectric thin film and including a plurality of electrode fingers;
- and
- a conductive layer provided on the second principal surface of the piezoelectric thin film;
- wherein
- an elastic wave propagating in the piezoelectric thin film is an S0 mode of a plate wave;
- and
- a change in an acoustic velocity in the S0 mode of the plate wave when a thickness of the interdigital transducer electrode is changed by one wavelength is not greater than about 9300 m/sec.
An elastic wave device comprising:
- a piezoelectric thin film formed from LiNbO3 and including a first principal surface and a second principal surface opposing the first principal surface;
- an interdigital transducer electrode provided on the first principal surface of the piezoelectric thin film and including a plurality of electrode fingers;
- and
- a conductive layer provided on the second principal surface of the piezoelectric thin film;
- wherein
- an elastic wave propagating in the piezoelectric thin film is an S0 mode of a plate wave;
- and
- in Euler Angles (φ, θ, ψ) of the piezoelectric thin film, φ is within a range of about 0°±20°, θ is within a range of not less than about 75° and not greater than about 145°, and ψ is within a range of about 0°±10°.
Dependencies are inferred from the claim text.