| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To get attenuation characteristics as designed and simplify post- adjustment for desired characteristics, by giving a degree of acuteness to the attenuation characteristics of a filter. <P>SOLUTION: The device comprises two kinds of filters (a reception side filter 14 and a transmission side filter 16) differing in the central frequency and a branching circuit 20, which has infinite impedance in the center frequency of the other filter, as viewed from the input/output terminal (in this case, the input/output terminal connected to an antenna 104) shared by the filters 14 and 16. The device is configured such that circuits 108 and 110 giving a sharpened attenuation characteristic are inserted and connected between each filter (14 and 16) and the branching circuit 20. <P>COPYRIGHT: (C)2003,JPO</p> |
