| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface acoustic wave device capable of establishing compatibility between excellent propagation characteristics and wide band of frequency characteristics. SOLUTION: A transversal filter 10 as one type of a surface acoustic wave device has a sapphire substrate 11, a propagation layer 12 formed of GaN thin film on the sapphire substrate 11, an input side interdigital transducer 13 formed on the surface of the propagation layer 12, and an output side interdigital transducer 14. In this filter 10, the interdigital transducers 13 and 14 are formed so that a ä11-20} direction being a direction where a surface acoustic wave to be excited by the interdigital transducers 13, 14 propagates at the lowest velocity in the surface of the propagation layer 12 may be aligned with the arrangement direction of the electrode fingers of the interdigital transducers 13, 14, and the line width and arrangement pitch of the electrode fingers may be changed in a direction orthogonal to the arrangement direction. COPYRIGHT: (C)2007,JPO&INPIT
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