| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent generation of ripples in a passband when connecting two longitudinal mode resonance type filters in parallel. <P>SOLUTION: When connecting two longitudinal mode resonance type filters in parallel, resonance points f21 and f31 of a first filter part 1 utilizing a double mode (designed so that two resonance points are located in a passband) are intervened between a resonance point f22 and a resonance point f32 of a second filter part 2 utilizing a triple mode (designed so that three resonance points are located in the passband). In addition, the respective filter parts 1 and 2 are configured so that phases of electric signals of these filter parts 1 and 2 that are extracted from an output port 22 are reversed to each other by 180°, and phases of the respective resonance points of the two longitudinal mode resonance type filters are different from each other by 180° from a low-frequency side toward a high-frequency side in the passband. <P>COPYRIGHT: (C)2013,JPO&INPIT |
