Heterojunction acoustic charge transport device technology

A brief description of the general acoustic charge transport (ACT) device and the operation of ACT devices is given. The application of GaAs-AlGaAs heterojunctions to ACT technology and the design of heterojunction ACT (HACT) devices is discussed. The performance characteristics of experimental HACT devices are presented. It is shown that Nyquist rate bandwidths with rolloffs less than 3dB can be obtained at signal output taps, and that transport currents of 100 mu A can be carried by the SAW with less than 4 mW/ lambda acoustic drive power. In addition, heterojunction FETs (field-effect transistors) with gain up to 10 GHz have been fabricated on HACT substrates, illustrating the compatibility of integrated circuitry with the HACT device substrate.<
>