Wireless, Passive Encoded Saw Sensors and Communication Links - Phase II

The innovation proposed here is a complete, wireless remote sensing solution using passive SAW Orthogonal Frequency Coded (OFC) sensors and a wireless interrogation system. Prior to the Phase I activity, wireless, passive sensors which could operate in a multi-sensor environment had not been successfully demonstrated. This is no longer the case. An experimental transceiver test bed has been built in Phase I and wireless temperature sensing has been demonstrated. Using OFC sensors developed by the University of Central Florida (UCF), remote temperature sensing at distances of up to several feet at 250 MHz has been accomplished. Further, work on electrically small antennas (ESA) has demonstrated that antennas more commensurate with the sensor size can be achieved. A smaller sensor/antenna package yields a more flexible sensor solution. Using the results form Phase I, it is proposed that a prototype interrogator be built and operation demonstrated at 915 MHz in a multi-sensor environment.