| 摘要 |
PROBLEM TO BE SOLVED: To provide a filter device which is suitable for UWB (ultra-wide band) having a sharp attenuation and a large amount of attenuation outside of a pass band. SOLUTION: The filter device comprises: first opposing reference electrodes 2a for sandwiching a laminate 1 of dielectric layers 1a therebetween; three or more first resonator electrodes 3a to 3d which are arranged sideways so as to be electromagnetically coupled each other and each of which has one end as a short-circuiting end and the other end as an opening end; a coupling electrode 4 which is located between the first resonator electrodes 3a to 3d to be sandwiched with the dielectric layers 1a and which has one and the other ends opposed to and electrically connected to the short-circuiting ends of the first- and final-stage resonator electrodes 3a and 3d, respectively; and input and output terminals 5 and 6 connected to the resonator electrodes 3a and 3d of the first and final stages. The coupling electrode 4 is a filter device which has a branch grounded between one and the other ends. The filter device has a sharp attenuation and a large amount of attenuation outside of a pass band. COPYRIGHT: (C)2009,JPO&INPIT
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