Using RFID technology for sensor purposes

In this paper we present new potentials of RFID technology in sensor systems. The working principle so far relied on measuring differences in the power received from the tag based on the environment conditions that surrounded the tag. Sensor systems with larger accuracy can be realized if tags with I²C interface are used, e.g. tags with UCODE I²C RFID chip from NXP Semiconductors. We have compared two versions of such sensors systems based on active and passive topology, respectively. The active topology has much more freedom in design, while the passive tag works in a limited distance range from the reader.