Wireless identification and sensing using surface acoustic wave devices

Today Surface Acoustic Wave (SAW) devices are used in many electronic produ cts, e.g. as filters in communications applications or for signal processin g in radar systems. Due to the dependence of the propagation characteristic of the microacoustic wave on many physical parameters (e.g. temperature or strain) it is possible to build SAW sensors for a great variety of physica l, chemical and biological parameters. SAW sensors are not only small, rugg ed and show small aging rates, they also can be used as wirelessly interrog able and completely passive sensors for many hostile environments. In this contribution the SAW device principles, design procedures and technological issues as well as examples of their use in certain measurement and identif ication applications are reviewed. (C) 1999 Elsevier Science Ltd. All right s reserved.