| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an SAW device for simultaneously realizing excellent frequency temperature characteristics and a high Q value within an operational temperature range. <P>SOLUTION: On a main surface of a crystal substrate 12 having Euler angles of (-1.5°≤ϕ≤1.5°, 117°≤θ≤142° and 42.79°≤¾ψ¾≤49.57°), an SAW device 11 has: an IDT 13 for exciting an SAW of an upper limit mode of a stop band; a pair of reflectors 14 disposed at both ends thereof; inter-electrode-finger grooves 17 recessed between electrode fingers 15a and 15b of the IDT 13; and inter-conductor-strip grooves 18 recessed between conductor strips 14a of the pair of reflectors 14. The wave length λ of the SAW and the depth G of the inter-electrode-finger grooves 17 satisfy the following relation: 0.01λ≤G. A line occupancy ratio η of the IDT 13 and the depth G of the inter-electrode-finger grooves 17 satisfy a predetermined relation. In addition, the line occupancy ratio η of the IDT 13 and a line occupancy ratio ηr of the pair of reflectors 14 are set to satisfy the following inequality: η<ηr. <P>COPYRIGHT: (C)2012,JPO&INPIT |
