| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a duplexer that has steep and temperature-stable guard band side skirt characteristics and covers a wider band. <P>SOLUTION: In the duplexer having a transmission filter and a reception filter having different passbands, out of a plurality of series resonators S1-S8 and a plurality of parallel resonators P1-P6 constituting the filters, first resonators S1-S4, P4-P6 forming skirt characteristics on a guard band side comprise a temperature-compensated TC-FBAR or a Love-wave-based surface acoustic wave resonator, and second resonators P1-P3, S5-S8 forming skirt characteristics on opposite sides to the guard band comprise a non-temperature-compensated FBAR or a surface acoustic wave resonator. The surface acoustic wave resonator for the second resonators may be a surface acoustic wave resonator using an LT substrate or a bonded substrate of LT and Sa, or a Love-wave-based surface acoustic wave resonator. <P>COPYRIGHT: (C)2013,JPO&INPIT |
