Patent ID: 6992547
Filing Date: 2006-01-31
Classification: H03H

Abstract:
1. A surface acoustic wave arrangement comprising a piezoelectric substrate; a first interdigital transducer and a second interdigital transducer being arranged along an acoustic path on the piezoelectric substrate; said first interdigital transducer having fingers with absolute finger center distances and finger widths, one of the absolute finger center distances and a combination of the absolute finger center distances and finger widths decreasing in the transverse direction for the first interdigital transducer; means dividing the acoustic path in the transverse direction into two edge tracks and a center track arranged between the edge tracks, the fingers of the first interdigital transducer being constructed so that the radiation of the acoustic wave in the edge tracks being selected from a bidirectional excitation and an excitation in a predominant direction, said means modifying the center track, so that the radiation of the acoustic wave takes place as a radiation selected from a radiation in a direction opposite the predominant direction and a radiation with an opposite phase.