Controlled gap surface acoustic wave device

A surface acoustic wave device incorporating a controlled gap and adaptable for use as a convolver, amplifier, and the like, comprising:

• a substrate of piezoelectric material having a polished upper surface capable of propagating surface acoustic wave energy;
• transducer means including a pair of spaced electro-acoustic transducers disposed on said substrate for defining a propagation beam path between said transducers;
• a semiconductor slab having a lower polished planar surface and an upper planar surface at least partially in contact with a conductive electrode;
• support means including a plurality of parallel, spaced elongated rails disposed on said propagation beam path between said transducers and having longitudinal axes aligned with said propagation beam path for separating said upper and lower planar surfaces a predetermined distance to couple surface acoustic wave energy propagating in said beam path to said slab;
• and
• pressure means coupled to said slab and to said substrate for exerting a uniform compressional force thereto forcing said planar surfaces toward each other while contact therebetween being prevented by said rails.