Patent ID: 6552631
Filing Date: 2003-04-22
Classification: H03H

Abstract:
A resonator-type. surface-acoustic-wave filter having a plurality of surface-acoustic-wave resonators with respective interdigital transducers and respective reflectors, each interdigital transducer being disposed between a respective pair of said reflectors, separated from the pair of reflectors by a certain distance, the surface-acoustic-wave resonators being coupled in a ladder network having at least one series-arm surface-acoustic-wave resonator and at least one shunt-arm surface-acoustic-wave resonator, the filter also having:at least one ground lead; a plurality of ground patterns, including a separate ground pattern connected to each said interdigital transducer of each said shunt-arm surface-acoustic-wave resonator and a separate ground pattern connected to each said reflector of each said shunt-arm surface-acoustic-wave resonator, said ground-patterns being electrically isolated from one another; and a plurality of conductors independently coupling said ground patterns to said at least one ground lead.