Forward, May 1981

The "applications" theme of this Issue is a reflection of the rapid progress in the surface-acoustic-wave (SAW) field since its beginnings in the late 1960's. Twelve years have elapsed since the first Special Issue on microwave acoustics including SAW's was published jointly by the Microwave Theory and Techniques Society and the Sonics and Ultrasonics Group. In November 1969, the SAW field was quite new, and a large fraction of the SAW papers published during 1969 were contained in that one Special Issue. Much of the Issue was devoted to speculations on the configuration and operation of future devices. By the time of the second joint Special Issue in April 1973, several types of SAW devices had been developed to the point of achieving very attractive levels of performance, and a few papers outlining the potential impact of these devices on systems applications were included the Issue. Increasingly sophisticated and high-performance SAW devices were the major theme of the May 1976 Special Issue of the Proceedings of the IEEE. By the end of the 1970's, SAW devices found increased acceptance as practical, high-performance components for signal generation and processing in electronic systems. Accordingly, the goal of this Special Issue is to emphasize the fact that SAW devices "have arrived" by providing a number of specific examples of how the devices are being effectively and profitably used in many different systems. Engineers and systems designers will find interest in the variety of complex signal-processing functions that can be performed with SAW devices in compact and simple configurations.