| 摘要 |
<p>A SAW filter device includes a SAW filter chip in which one-port surface acoustic wave resonators each including an IDT made of Al or an Al alloy, are provided on a ¸-rotated Y-cut X-propagation LiNbO 3 substrate. The cutting angle ¸ of the ¸-rotated Y-cut X-propagation LiNbO 3 substrate is in the range between 50° and 55°. The normalized film thickness of the IDT 100h/» (%) (h denotes the thickness of the IDT and » denotes the wavelength of a surface acoustic wave) is in the range between 2% and 4%. The duty ratio of the IDT is equal to or less than 0.4.</p> |
