Verbesserte Akusto-elektrische Oberflächenwellenanordnung.

摘要

The invention relates to a surface wave acoustoelectric device of a type comprising, on a large face of a flat piezoelectric substrate: … …  - a first row (10) of parallel conducting fingers having a selected individual geometry and distributed according to a selected distribution along this row, …  - a second row (20) of parallel conducting fingers having a selected individual geometry and distributed according to a selected distribution along this row, …  - the second row being distanced from the first in such a way as to permit the propagation of acoustic surface waves between the fingers of the first row and those of the second, which imparts to the device spectral and/or temporal characteristics defined by the acoustic propagation and the frequency selectivity due to the geometry of the fingers. … …According to the invention the geometries of the fingers are selected, correspondingly from one row to the other, to achieve wide frequency band acoustic coupling and one of the two distributions or finger-engagement sequence (20M) is modified substantially periodically. ……