VERTICAL COUPLING SURFACE ACOUSTIC WAVE FILTER

摘要

In a longitudinally coupled multi-mode surface acoustic wave filter which has an assembly of more than two interdigital transducers (IDTs) 3, 5 and 5 formed on a piezoelectric substrate 1 and reflectors 2 and 6 composed of shorted grating electrodes 101 and 102 different in pitch from the IDTs, the grating electrodes 101 and 102 are weighted so that their numbers vary linearly with the position in the direction perpendicular to the direction of propagation of surface acoustic waves. <IMAGE>