Patent ID: 6943649

Claim:
A surface acoustic wave filter comprising: a piezoelectric substrate having an input electrode pad and an output electrode pad; a plurality of serial surface acoustic wave resonators and parallel surface acoustic wave resonators arranged in a ladder configuration between said input electrode pad and said output electrode pad on said piezoelectric substrate; a grounded electrode pad connected to at least one of the plurality of parallel surface acoustic wave resonators; and a grounded electrode pattern directly connected to said grounded electrode pad and arranged on said piezoelectric substrate such that the grounded electrode pad and the grounded electrode pattern surround at least one of said input electrode pad and said output electrode pad on at least three sides thereof; wherein the grounded electrode pattern is provided between at least one of said input electrode pad and said output electrode pad and an edge of said piezoelectric substrate, such that the grounded electrode pattern is spaced from the edge of said piezoelectric substrate.