发明名称 |
Laminated filter, duplexer, and mobile communication apparatus using the same |
摘要 |
A laminated filter comprising a plurality of resonator electrodes, an inter-resonator coupling capacitor electrode for coupling adjacent resonators, and two input/output coupling capacitor electrodes for coupling input/output terminals and the resonator electrodes. This provides a capacitor electrode for electrically connecting one side of the input/output terminals with a portion of the input/output coupling capacitor electrode, wherein the input/output coupling capacitor electrode and the capacitor electrode are a parallel circuit. This structure forms a parallel resonance circuit in the input/output terminal, to provide an additional attenuation pole besides an attenuation pole formed by electromagnetic coupling between the resonators and an inter-resonator capacitance, thereby realizing a laminated filter of a high attenuation. With this structure, a duplexer can be made using a plurality of the filters of this invention without requiring a phase-shifting circuit.
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申请公布号 |
US6492886(B1) |
申请公布日期 |
2002.12.10 |
申请号 |
US20000613554 |
申请日期 |
2000.07.10 |
申请人 |
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. |
发明人 |
KUSHITANI HIROSHI;YAMADA TORU;FUJIKAWA MAKOTO |
分类号 |
H01P1/203;H01P1/213;(IPC1-7):H01P3/08;H01P7/00;H01P5/12 |
主分类号 |
H01P1/203 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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