| 摘要 |
PROBLEM TO BE SOLVED: To solve the following problem: in an elastic wave filter where taper type IDTs are formed as an input electrode and output electrode, when a surface wave propagates from the input electrode toward the output electrode, the surface wave reaches an area away from an area where an electrode finger is formed so as to become an arrangement pattern in response to a wavelength of a propagating frequency because of a refraction and diffraction, thereby degrading an attenuation characteristic. SOLUTION: A short grating electrode provided with a plurality of electrode fingers is formed between the input electrode and output electrode, and the arrangement pattern of the electrode finger of the short grating electrode is formed as a periodic structure continuing from at least one pattern of the input electrode and output electrode to suppress the refraction and diffraction. COPYRIGHT: (C)2009,JPO&INPIT
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