Surface acoustic wave devices

The paper outlines the design features, principles of operation, fabrication, and electronic applications of surface acoustic wave (SAW) devices. Surface acoustic waves can exist in any elastic medium at its surface, and devices using these waves are made on piezoelectric media having a preferred direction of propagation. A SAW device usually consists of the SAW element on its substrate plus any auxiliary elements and the packaging of the complete device. Basic design variables are identified and discussed, and computer-based design of a SAW device is examined. Design of a SAW device generally goes through several iterations on the computer before it takes the next most important step, making a SAW photo mask. Ways in which SAW delay lines can be used in the generation of frequencies are analyzed. Basic processes for forming transducer patterns on substrates are described, along with the sequence of operations in making a SAW device. The applications discussed include oscillator, resonator, correlator, and SAW delay lines in computers.