Surface Acoustic Wave Delay Lines

Abstract

Surface acoustic wave (SAW ) delay lines are special microwave components that have been used for electronic analog signal processing since the early 1970s. A tremendous variety of devices and systems for consumer, commercial, and military applications have been developed, running now at an annual rate of some hundred million U.S. dollars. SAW filters, especially linear and nonlinear delay lines, as well as reflective delay lines play a key role in the radiofrequency (RF ) and intermediate‐frequency (IF ) stages of many electronic systems such as radar systems, spread‐spectrum telecommunication systems, and wireless passive sensor systems. The objective of this article is to provide an overview of the latest developments in SAW delay lines and to identify novel emerging applications, especially in the field of wireless communications and sensing. The pertinent key issues for the successful design and mass fabrication of SAW devices are addressed and the underlying operating principles are discussed.

Multi-Channel Data Transmission with X Wave and Bessel Pulses

“…Because the group velocity of Bessel pulses is slower than c and decreases as α increases, the Bessel pulses can be used for delay lines. Currently, acoustic delay lines are made of surface acoustic wave (SAW) devices [34][35][36]. The advantage of using Bessel pulses versus SAW is that the delay time can be easily changed with α .…”