| 摘要 |
PROBLEM TO BE SOLVED: To provide a diplexer of a configuration capable of suppressing harmonics generated due to leakage of a low-pass side transmitted signal into a high-pass side circuit without affecting other characteristics in a front end module, and to provide a front end module using the diplexer. SOLUTION: A serial resonance circuit of an inductor L4 and a capacitor C6 is arranged between a signal path of high-pass through side constituting a diplexer and earth, as a first trap circuit 10. A parallel resonance circuit of an inductor L5 and a capacitor C5 is inserted into the signal path as a second trap circuit 11. The resonant frequency of the trap circuits 10 and 11 is set to a frequency band used by a communication system of the low-pass side or a frequency band close to the above. COPYRIGHT: (C)2004,JPO
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