Acoustoelectric interactions in acoustic-surface-wave devices

The principles of a wide range of acoustic-surface-wave devices employing acoustoelectric interactions with semiconductors are described. It is shown that acoustoelectric amplifiers can increase the dynamic range of a delay-line filter. Such devices have been operated on a CW basis and are beginning to become practical. The acoustic convolver and its derivative devices, the optical scanner, the acoustic focusing and imaging devices, and the storage correlator are described. Several of the signal processing applications of the convolver are discussed. Various types of constructional techniques, including the air gap convolver and acoustoelectric amplifier, the strip coupled and external diode convolvers, the use of piezoelectric semiconductors, deposition of a semiconductor on a piezoelectric substrate, and deposition of a piezoelectric material on a semiconducting substrate are discussed.