POLARIZATION TYPE SURFACE ACOUSTIC WAVE FILTER

摘要

PROBLEM TO BE SOLVED: To provide a high-performance SAW filter which has lower insertion loss in a passing band and a higher attenuation quantity in a lower attenuation range of the passing band. SOLUTION: The polarization type SAW filter comprising a two-terminal- couple circuit 1 (180) for filter which constitutes a lattice type SAW filter by using a SAW resonator and a two-terminal-couple circuit 2 (181) for impedance comprising a series connection of impedance has the impedance of the two- terminal-couple circuit 2 (181) for impedance so constituted as to form an attenuation band of specified width having a sufficient attenuation characteristics on the low-frequency side of the passing band. COPYRIGHT: (C)2003,JPO