| 摘要 |
PROBLEM TO BE SOLVED: To sufficiently enlarge an attenuation based on a change of a formed attenuation pole not only in a high frequency side attenuation band but also in a low frequency side attenuation band in spite of a miniaturized configuration. SOLUTION: The polarized SAW filter using a passband ladder type SAW filter using a SAW resonator, has a serial arm SAW resonator and a second parallel arm SAW resonator, a two-terminal-pair circuit is serially connected to the passband ladder type SAW filter, the two-terminal-pair circuit is composed of three inductors provided between the passband ladder type SAW filter which is provided on the surface of a piezoelectric substrate, and a common terminal disposed in the area surrounding the passband ladder type SAW filter on the surface side of the piezoelectric substrate, and the common terminal is provided on the side of a package closest to the other terminals of first and second parallel arm SAW resonators. COPYRIGHT: (C)2005,JPO&NCIPI
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