Ultrasonic traveling-wave devices for communications

As a result of advances in transducer materials, wave propagation technology, and device inventions, ultrasonic delay lines are now available with a large variety of delay characteristics and for operation over a wide range of frequencies that extend from the kilocycle to the microwave range. In this paper the principles of operation and characteristics of presently available designs will be reviewed, together with a description of some of the delay and amplification devices that are currently being developed and which should become available shortly.