Breaking the Range Limit of RFID Localization: Phase-based Positioning with Tunneling Tags

The measurements reported in this work demonstrate the ability to extend the localization range of low-powered RFID tags to distances usually not achievable with conventional RFID technology. The ranging technique is performed through the Frequency Domain Phase Difference Of Arrival (FD-PDOA) method on a 5.8 GHz Tunneling Tag, both in a multipath-rich indoor environment and outdoor, at distances up to 15 meters from the reader. Range estimation errors as low as 1.95% were observed, moreover, an EIRP of only 10.5 dBm, a biasing power for the Tunneling Tag of only 21.32 μW (80 mV), and a tag antenna gain of 1 dBi suggest the potential of power-stingy Tunneling Tags to be used in low-powered RFID localization applications for very long-range scenarios.