| 摘要 |
PROBLEM TO BE SOLVED: To realize a surface acoustic wave filter of which the attenuation characteristics and pass characteristics can be set arbitrarily concerning the surface acoustic wave filter which is used for cellular phones and other mobile communication equipment. SOLUTION: The surface acoustic wave filter has resonators 71, 72, 73, and 74. A transmission line 77 equivalent to that the phase of which is rotated arbitral angle at the series resonance frequency of a series arm consisting of the resonators 74, 72, or the parallel resonance frequency of a parallel arm consisting of the resonators 73, 71 is connected between the connection point of the resonator 74 to the resonator 73, and the input terminal of the resonator 72. COPYRIGHT: (C)2004,JPO
|
