Lamb wave device
AssigneeNGK Insulators, Ltd.
InventorsTomoyoshi Tai, Masahiro Sakai, Yukihisa Ohsugi
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Abstract
There is provided a lamb wave device with small variations in frequency, the device including: a piezoelectric thin film; an IDT electrode which is provided on a main surface of the piezoelectric thin film; and a support structure which supports a laminate of the IDT electrode and the piezoelectric thin film, and is formed with a cavity that isolates the laminate, wherein a film thickness h of the piezoelectric thin film and a pitch p of a finger of the IDT electrode are selected such that a lamb wave is excited at a target frequency, the lamb wave making dispersibility of a sonic velocity v with respect to the film thickness h of the piezoelectric thin film small.
Claims6
A lamb wave device, comprising:
- a piezoelectric thin film;
- an IDT electrode which is provided on a main surface of said piezoelectric thin film;
- and
- a support structure which supports a laminate of said piezoelectric thin film and said IDT electrode, wherein
- a film thickness h of said piezoelectric thin film and a pitch p of a finger of said IDT electrode are selected such that a lamb wave, with which an absolute value of a change coefficient Δv/Δ (h/λ) of a sonic velocity v with respect to a ratio h/λ of said film thickness h of said piezoelectric thin film to a wavelength λ is not larger than 2000 m/s, is excited at a target frequency.
Dependencies are inferred from the claim text.