| 摘要 |
A signal separation device is a duplexer in which a reception frequency band is located at higher frequencies than a transmission frequency band. A series arm of a ladder transmission filter includes a plurality of series arm resonators, and parallel arms respectively include parallel arm resonators. The parallel arm resonators include the parallel arm resonators having resonant frequencies lower than those of the series arm resonators and the parallel arm resonator that has a resonant frequency which is located within the reception frequency band and which is higher than the resonant frequency of the series arm resonators and that has a lower capacitance than the series arm resonators and the parallel arm resonators. |
