| 摘要 |
<p>An elastic wave filter having a balance-unbalance conversion function, an input/output impedance ratio of approximately 1, and further reduced sizes. In the elastic wave filter (1), the second IDT (12) of a first elastic wave filter section (6) is connected with an unbalance terminal (3) while being divided in the direction of crossing width, first and second divided IDT portions (12a, 12b) are connected in series between the unbalance terminal (3) and the ground potential, the fifth IDT of the second elastic wave filter section (7) connected with the first elastic wave filter section (6) has first and second divided IDT portions (22a, 22b) divided in the propagation direction of elastic wave, and the divided IDT portions (22a, 22b) are connected with first and second balance terminals (4, 5).</p> |
