Lifecycle Extension of Long Range UHF RFID Tags based on Energy Harvesting

Recently applications of UHF RFID systems are often requiring sensing and monitoring capabilities on the transponder side as well as long operating ranges (long range sensor tag). Such functionality results in a high energy consumption of the tag on the one hand but also requires an uninterrupted energy supply on the other hand. This is not achievable with reader-powered passive UHF RFID Systems; an on-board energy source (battery) is necessary. Such energy store defines and limits the lifetime of a sensor tag, which is a key parameter specifying the reliability and the quality of this type of UHF RFID system. This paper describes the combination of special power saving techniques with novel energy storage structures incorporating energy harvesting devices to guarantee a reasonable lifetime of the resulting sensor tag architecture.