SURFACE ACOUSTIC WAVE PASSIVE TRANSPONDER HAVING ACOUSTIC REFLECTORS

摘要

A passive transponder for use in an interrogation/transponder system comprises a substrate having a substrate surface defining a path of travel for surface acoustic waves; at least one transducer element arranged on the surface for converting between electrical energy and surface acoustic wave energy which propagates along the path of travel; and a circuit, connected to the transducer element(s), for supplying interrogating signals to the transducer element(s) and for receiving reply signals therefrom. In order to minimize insertion losses in the substrate, acoustic wave reflectors are provided to reflect the surface acoustic waves back towards the transducer element(s).