| 摘要 |
PROBLEM TO BE SOLVED: To improve the Q value of a surface acoustic wave resonator and to lower the CI value. SOLUTION: A line occupation rate at which an electromechanical coupling coefficient of an IDT 12 becomes maximum and a line occupation rate at which reflection of a surface acoustic wave becomes maximum, are different. The IDT 12 has a first region 14a arranged at a center part, and a second area 14b and a third area 14c arranged on both sides thereof, and electrode digit intervals are uniform in the respective first region 14a, second region 14b, and third region 14c, and larger in the second region 14b and third region 14c than in the first region 14a. Line occupation rates area uniform in the respective first region 14a, second region 14b, and third region 14c; and the first region 14a has a line occupation rate at which an electromechanical coupling coefficient is larger than those of the second region 14b and third region 14c, and the second region 14b and third region 14c have line occupation rates at which reflection of a surface acoustic wave is larger than that of the first region 14a. COPYRIGHT: (C)2010,JPO&INPIT |
