Signal Pattern-Based UHF RFID Sensor Systems and their Dependable Operation

This talk presents an Ultra-High Frequency (UHF) Radio-Frequency IDentification (RFID) sensor system. The system relies on transponder (tag) signal patterns to communicate the sensor state and offers constant wireless power transfer and system setup independence. The sensor system uses a sophisticated modulation of amplitude and phase, relating a specific tag signal pattern to a set of discrete sensor states. The concept differs from the previously presented concepts, in which one specific tag signal is related to one discrete sensor state. We give a prototype system to sense water filling levels and its verification by measurements, investigating its dependable system operation. In addition, we discuss the localization of signal pattern-based UHF RFID sensor tags, demonstrating negligible inter-dependencies of signal pattern-based sensing and phase-based tag localization. Finally, we present a further analysis of signal-pattern-based sensor systems that shows the system’s ability to operate robustly in multipath environments important for application environments.