  A self-powered autonomous RFID device with sensing and computing capabilities
is presented in this paper. Powered by an RF energy-harvesting circuit enhanced
by a DC-DC voltage booster in silicon-on-insulator (SOI) technology, the device
relies on a microcontroller and a new generation I2C-RFID chip to wirelessly
deliver sensor data to standard RFID EPC Class-1 Generation-2 (Gen2) readers.
When the RF power received from the interrogating reader is -14 dBm or higher,
the device, fabricated on an FR4 substrate using low-cost discrete components,
is able to produce 2.4-V DC voltage to power its circuitry. The experimental
results demonstrate the effectiveness of the device to perform reliable sensor
data transmissions up to 5 meters in fully-passive mode. To the best of our
knowledge, this represents the longest read range ever reported for passive UHF
RFID sensors compliant with the EPC Gen2 standard.
