| 摘要 |
<p>A surface acoustic wave (SAW) filter which exhibits both low insertion loss and small ripple in the passband. Apodized group-type recessed electrodes (16, 18) are utilized to form the transducers. The grouping of the electrodes functions to reduce reflection between electrodes and apodization of the electrodes functions to increase the sideband rejection. However, merely combining these techniques is inadequate since the apodization process produces additional ripple between adjacent electrodes, thus increasing the passband ripple. By recessing the apodized groups of electrodes, this reflection is minimized and a SAW filter formed in accordance with the present invention is thus capable of providing both low insertion loss and small ripple with high sideband rejection.</p> |
