A 915 MHz Wireless Correlator Multi-Sensor System for SHM

Abstract

Novel wireless RFID surface acoustic wave (SAW) sensor devices have been developed to address needs that often cannot be met by other technologies. These sensors are fully passive, and use only the interrogation energy to encode the device RFID and sensor information. This work will present results from an operational 915 MHz wireless SAW sensor system that demonstrates 8 SAW temperature sensors, received simultaneously from a single interrogation signal, having over 3 meters range. In addition, examples of room temperature reversible hydrogen SAW gas sensors with over 20 dB dynamic range and real-time response time (<1 sec) will be shown. An adaptive matched filter and synchronous correlator techniques are used at the receiver to extract the sensor information. The sensor examples and transceiver hardware and software approach will be discussed.