A 915 MHz SAW Sensor Correlator System

Previous work has been presented on passive wireless surface-acoustic-wave (SAW) sensors using the orthogonal frequency coding (OFC) technique (Malocha et al., Proc. Int. Soc. Opt. Eng. (SPIE), Aug. 23-27, 2004, vol. 2, pp. 1082-1085), Pavlina et al., Proc. IEEE Int. Conf. RFID, 2009, pp. 110-115). This paper will present a SAW sensor correlator system and its key operational parameters. Description of the radio frequency (RF) transceiver system and the OFC SAW temperature sensors is provided for parameter characterization. The system is based on a software radio approach and an analysis of the analog-to-digital converter (ADC) parameters and receiver noise in temperature extraction is presented. Initial experimental results for a four-sensor system operating over a 280 degrees C range are given