Abstract: A waveguide for surface acoustic waves comprises a substrate for supporting propagation of surface acoustic waves along a direction at a substrate velocity and a dielectric structure disposed above the substrate along the propagation direction of the surface acoustic waves. The structure includes a central portion disposed along the propagation direction, first and second intermediate portions respectively disposed along each opposed side of the central portion along the propagation direction, and first and second outer portions respectively disposed along each outer side of the first and second intermediate portions along the propagation direction. The central, intermediate and outer portions each has first, second and third intrinsic surface acoustic wave propagation velocities along the propagation direction of the surface acoustic waves, respectively and the first velocity is intermediate of the second and third velocities.

Abstract: An acoustic charge transport device comprises a substrate with a layer disposed thereon; a channel disposed within the layer for providing a propagation path for a surface acoustic wave; a contact operably connected and disposed at one end of the channel for injecting an electronic signal into the channel; a transducer disposed at the one end of the channel for generating and propagating the surface acoustic wave through the channel; a plurality of sensing electrodes operably associated with the channel and disposed along the propagation path of the surface acoustic wave for non-destructively sensing the electronic signal; and a plurality of active buffer circuits each having an input operably connected to respective sensing electrode and an output operably connected to an output circuit.

Abstract: A method for electrically isolating an integrated circuit element in an acoustic charge transport device comprises the steps of providing a semi-insulating substrate; providing an epitaxial layer with a thickness and carrier concentration appropriate for an ACT device; providing a circuit element semiconductor layer in the epitaxial layer for construction of an integrated circuit element, the layer having a thickness substantially less than the thickness of the epitaxial layer and having a carrier concentration substantially greater than the ACT epitaxial layer; laterally isolating the semiconductor layer from other regions of the ACT epitaxial layer; and bombarding the semiconductor layer with protons at a dose sufficient to provide significant vertical electrical isolation from underlying regions of the epitaxial layer semi-insulating with minimal detrimental effect on the electrical characteristics of the semiconductor layer.