Integrable SAW sensor with identification facility

Sensor applications such as gas monitoring for environmental protection require wirelessly addressable sensors possessing a read out feasibility by a radio signal. We have developed a system concept for a fully integrable SAW sensor on GaAs which derives the advantage of monolithic integration of fast electronic circuits and highly sensitive SAW components on the same substrate. First we have realized the SAW delay line for mass detection and a SAW coder on GaAs. The electronic circuits were built as discrete components. A sensor output signal containing the address and the measuring value has been generated, transmitted as a spread spectrum signal by air, and received by correlation techniques