Acoustic surface wave effect sensor with remote interrogation for e.g. ID tag

摘要

The surface wave effect device is used for the remote, passive sensing of parameters. The unit has a finger electrode structure which when electrically excited generates acoustic waves. For temp. sensing a carrier material (30) has a piezoelectric substrate (130) of lithium niobate or similar that is temp. sensitive. Also on the surface is similar element as a reference device (230).The unit is interrogated by an incoming radio signal received by an antenna (16) and the measured output is transmitted by a second antenna.