| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an SAW device for improving an electromechanical coupling coefficient and exhibiting a stable oscillation while maintaining excellent frequency temperature characteristics within an operational temperature range. <P>SOLUTION: On a main surface of a crystal substrate 2 having Euler angles of (ϕ=0°,θ=123°,ψ), an SAW device 1 has: an IDT 3 for exciting an SAW of an upper limit mode of a stop band; and inter-electrode-finger grooves 8 recessed between electrode fingers 6a and 6b of the IDT 3. The depth G of the inter-electrode-finger grooves 8, the film thickness H of the electrode fingers 6a and 6b and the wave length λ of the SAW satisfy the following relation: 1≤G/λ≤4 and 1≤H/λ≤4. In addition to the above, a line occupancy ratio η and an Euler angle ψ of the IDT 3 are determined in such a manner that an electromechanical coupling coefficient is equal to 0.052% or more and further that the frequency temperature characteristics are equal to 20 ppm or less within an operational temperature range. <P>COPYRIGHT: (C)2012,JPO&INPIT |
