Surface wave devices for processing signals

A device for processing and storing signals comprising

• a first piezoelectric substrate capable of propagating acoustic wave signals on a selected surface thereof;
• at least one transducer means formed on said selected surface for generating surface acoustic waves traveling on said surface along a selected direction thereof in response to electrical signals;
• a semiconductor material positioned so as to have a first surface thereof adjacent and spaced from said selected surface of said first substrate to form an interaction region which includes the region at or near said surfaces and the spatial region therebetween;
• at least one of said piezoelectric substrate surface regions and said semiconductor material surface region being capable of operating as a storage element for electrons or carriers;
• a layer of conductive material disposed on a second surface of said semiconductor material, said layer forming an electrode;
• means for providing a first signal at said at least one transducer means to produce a first traveling acoustic wave signal along said selected surface of said first substrate;
• a source of electrons or carriers;
• means for applying a time-varying second signal uniformly over said interaction region when said first signal is positioned on the surface of said piezoelectric substrate at said interaction region to provide time-varying properties thereof, the interaction of said first and second signals thereby causing electrons or carriers to migrate from said source into said at least one of said storage elements in accordance with said interaction to provide an altered stationary conductivity pattern in said semiconductor material, which altered conductivity pattern remains stored in said semiconductor material for a selected time period and represents said interacted first and second signals.