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US 2016/0294361 A1Published application
Elastic wave device and filter device
AssigneeMurata Manufacturing Co., Ltd.
InventorsTakashi YAMANE, Hideki IWAMOTO, Keiji OKADA, Syunsuke KIDO, Masanori OTAGAWA, Ippei HATSUDA, Korekiyo ITO
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Abstract
An elastic wave device includes IDT electrodes stacked on a piezoelectric thin film. The IDT electrode includes a plurality of first electrode fingers and a plurality of second electrode fingers. A line connecting the distal ends of the first electrode fingers or the distal ends of the second electrode fingers extends obliquely with respect to a propagation direction of an elastic wave at an oblique angle ν. The oblique angle ν is about 0.4° or more and about 10° or less.
Claims24
An elastic wave device comprising:
- a piezoelectric film made of LiTaO3;
- and
- an IDT electrode located on one surface of the piezoelectric film;
- wherein
- the IDT electrode includes a plurality of first electrode fingers and a plurality of second electrode fingers that are alternately arranged;
- a thickness of the piezoelectric film is about 10λ or less when λ is a wavelength determined by a pitch of the electrode fingers of the IDT electrode;
- and
- a direction of a line connecting distal ends of the plurality of first electrode fingers and a direction of a line connecting distal ends of the second electrode fingers are at an oblique angle ν with respect to a propagation direction ψ of an elastic wave excited by the IDT electrode, the propagation direction ψ being determined by Euler angles (φ, θ, ψ) of the LiTaO3, and the oblique angle ν is in a range of about 0.4° or more and about 15° or less.
5 more elements
An elastic wave device comprising:
- a piezoelectric film made of LiTaO3;
- a support substrate;
- a high acoustic velocity film that is located on the support substrate and in which an acoustic velocity of a bulk wave that propagates through the high acoustic velocity film is higher than an acoustic velocity of an elastic wave that propagates through the piezoelectric film;
- a low acoustic velocity film that is stacked on the high acoustic velocity film and in which an acoustic velocity of a bulk wave that propagates through the low acoustic velocity film is lower than an acoustic velocity of a bulk wave that propagates through the piezoelectric film;
- and
- an IDT electrode located on one surface of the piezoelectric film;
- wherein
- the piezoelectric film is stacked on the low acoustic velocity film;
- the IDT electrode includes a plurality of first electrode fingers and a plurality of second electrode fingers that are alternately arranged;
- a thickness of the piezoelectric film is about 10λ or less when λ is a wavelength determined by a pitch of the electrode fingers of the IDT electrode;
- and
- a direction of a line connecting distal ends of the plurality of first electrode fingers and a direction of a line connecting distal ends of the second electrode fingers are at an oblique angle ν with respect to a propagation direction ψ of an elastic wave excited by the IDT electrode, the propagation direction ψ being determined by Euler angles (φ, θ, ψ) of the LiTaO3, and the oblique angle ν is in a range of about 0.4° or more and about 15° or less.
9 more elements
An elastic wave device comprising:
- a piezoelectric film made of LiTaO3;
- a high acoustic velocity support substrate in which an acoustic velocity of a bulk wave that propagates through the high acoustic velocity support substrate is higher than an acoustic velocity of an elastic wave that propagates through the piezoelectric film;
- a low acoustic velocity film that is stacked on the high acoustic velocity support substrate and in which an acoustic velocity of a bulk wave that propagates through the low acoustic velocity film is lower than an acoustic velocity of a bulk wave that propagates through the piezoelectric film;
- and
- an IDT electrode located on one surface of the piezoelectric film;
- wherein
- the piezoelectric film is stacked on the low acoustic velocity film;
- the IDT electrode includes a plurality of first electrode fingers and a plurality of second electrode fingers that are alternately arranged;
- a thickness of the piezoelectric film is about 10λ or less when λ is a wavelength determined by a pitch of the electrode fingers of the IDT electrode;
- and
- a direction of a line connecting distal ends of the plurality of first electrode fingers and a direction of a line connecting distal ends of the second electrode fingers are at an oblique angle ν with respect to a propagation direction ψ of an elastic wave excited by the IDT electrode, the propagation direction ψ being determined by Euler angles (φ, θ, ψ) of the LiTaO3, and the oblique angle ν is in a range of about 0.4° or more and about 15° or less.
8 more elements
Dependencies are inferred from the claim text.