| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent the deterioration of signal passing characteristics between a shared signal terminal pair and a first and second terminal pair of a filter even if downsized. <P>SOLUTION: An antenna duplexer includes: the shared signal terminal pair T0; the first terminal pair T1 for transmitting a signal to the shared signal terminal pair T0; the second terminal pair T2 for receiving the signal from the shared signal terminal pair T0; a first piezoelectric thin film resonator filter F1 connected between the shared signal terminal pair T0 and the first terminal pair T1; a second piezoelectric thin film resonator filter F2 connected between the shared signal terminal pair T0 and the second terminal pair T2; an inductive element L connected between the shared signal terminals T0 in pairs; inductive elements L1, L2 connected to the first piezoelectric thin film resonator filter F1; and inductive elements L3, L4, L5 connected to the second piezoelectric thin film resonator filter F2. Since the distance between the inductive element L and the inductive elements L2, L5 are selected greater to the utmost extent, the capacitive coupling and the inductive coupling between the inductive element L and the inductive elements L2, L5 can be decreased. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
