| 摘要 |
<p>There is provided a surface acoustic wave filter device in which the balancing between first and second balanced terminals and the differential characteristics of attenuation characteristics are improved in a frequency region higher than a passband. In the surface acoustic wave filter device (4), first and second surface acoustic wave filter elements (13, 14) are connected in parallel with an unbalanced terminal (9), and second and third IDTs (22, 23) among first to third IDTs (21 to 23) are connected to a first balanced terminal (10) and fifth and sixth IDTs (25, 26) among fourth to sixth IDTs (24 to 26) to a second balanced terminal (11).Further, a first earth terminal (61) is disposed on the side of the unbalanced terminal (9) and closer to the first surface acoustic wave filter element (13) side, and a third earth terminal (65) is disposed so that the third earth terminal (65) and the first earth terminal (61) are symmetrical with respect to the center between the first and second surface acoustic wave filter elements (13, 14).</p> |
