| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a small duplexer with superior isolation characteristics. Ž<P>SOLUTION: In the duplexer, a high pass filter 4 and a low pass filter 3, which consist of ladder type filter, are provided on a common piezoelectric substrate 11. The duplexer includes a first elastic wave resonator 31a contained in the filter on one side, a second elastic wave resonator 42c contained in the filter on the other side, and a first additional grating reflector 86a arranged between the resonators 31a, 42c for reflecting an elastic wave leaked from a grating reflector of the first elastic wave resonator 31a. In the first elastic wave resonator 31a, an additional grating reflector is not provided on the side opposite to the second elastic wave resonator 42c. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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