| 摘要 |
PROBLEM TO BE SOLVED: To ensure attenuation ranges for both a transmission filter and a reception filter, and to achieve sufficient steepness. SOLUTION: A filter has at least one series resonator and a plurality of parallel resonators, and the series resonator and parallel resonators have an excitation electrode and a reflector. When the plurality of parallel resonators have different resonance frequencies from each other, at least one parallel resonator of the parallel resonators except parallel resonators having the highest resonance frequency of the plurality of parallel resonators has a reflector having a pitch narrower than that of the excitation electrode. COPYRIGHT: (C)2011,JPO&INPIT |
