ACOUSTIC WAVE FILTER

摘要

An acoustic wave filter comprising a piezoelectric substrate body upon which at least two digital structures are formed and which comprise input and output converters and form a selective wave reflective pair with at least one of the digital structures having a wide band amplitude characteristic F1 and at least one of the other digital structures having a narrower frequency band amplitude characteristic and wherein the mean frequency F1 of the wider band F1 digital structure is displaced relative to the mean frequency f2 of the digital structure which has a narrower frequency band F2 by a frequency of .DELTA.f on either side of the mean frequency f1 so that one of the zero locations fR1'2 of the interfering signal FR of the interdigital reflections of the wider band characteristic F1 is placed close to the value of the mean frequency f0 of the filter.