| 摘要 |
<p>A surface acoustic wave (SAW) bandpass filter having improved out-of-band rejection and minimization of problems arising from bulk waves, diffraction and other effects. The filter comprises a phased array of input transducers disposed on a substrate to act in the manner of a diffraction-effect device, and a single interdigital output transducer positioned to receive acoustic energy only in a selected band of frequencies transmitted by the input array. The input array is preferably amplitude-weighted in accordance with a combination of techniques, includes width aperture weighting, resistive weighting, capacitive weighting, serial-parallel transducer connections, and source withdrawal.</p> |
