Surface acoustic wave element and electronic equipment
OwnerTsukasa Funasaka, Masahiro Oshioinventors
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Abstract
A surface acoustic wave element is provided including, as a substrate, a quartz-rotator Y plate whose Euler angle is expressed as (0, θ, ψ), and an IDT and reflectors provided on this substrate. The IDT is formed of Al as its main ingredient, and arranged so that an angle ψ, which the propagation direction of a surface acoustic wave and the X-axis of the quartz-rotator Y plate make, is 90±10°, and a normalized film-thickness H/λ of the IDT, and the cut angle θ satisfy the following Relation A: θ min≧θ≧θ max (where, θ=129 through 144°); θ min=857.06(H/λ)2+23.656(H/λ)+123.68; and θ max=2502.4(H/λ)2+73.1(H/λ)+121.7.
Claims7
A surface acoustic wave element, comprising:
- a quartz-rotator Y plate having a Euler angle expressed with (0, θ, ψ);
- and
- an interdigital transducer provided on the quartz-rotator Y plate, and changing one of
- an electric signal into a surface acoustic wave that propagates near a surface of the quartz-rotator Y plate;
- and
- the surface acoustic wave that propagates near the surface of the quartz-rotator Y plate into an electric signal,
- wherein the interdigital transducer is formed substantially of Al and arranged so that an angle ψ, which a propagation direction of the surface acoustic wave and the X-axis of the quartz-rotator Y plate make, is 90±10°, and a normalized film-thickness H/λ of the interdigital transducer (H denotes an average thickness of a comb-teeth electrode, and λ denotes a wavelength of the surface acoustic wave) and a cut angle θ are set to satisfy Relation A shown below:
- θ min≦θ≦θ max (where, θ=129 through 144°);
- θ min=857.06(H/λ)2+23.656(H/λ)+123.68;
- and
- θ max=2502.4(H/λ)2+73.1(H/λ)+121.7.
Dependencies are inferred from the claim text.