Ambient backscatter communication for RFID tags

Abstract

A technology called ambient backscatter communication (AmBC) that requires no batteries or wires and depends on harvested radio frequency (RF) energy to power the radio frequency identification (RFID) tag has been proposed. AmBC is a mechanism in which a device can communicate with others by backscattering ambient RF signals without any additional power supply. AmBC system consists of three main components; RF source, tag, and the reader. As devices get smaller, providing for wires and reader batteries becomes more expensive, ambient signals relatively represent a good source of power for RFID tags compared to reader batteries. RFID tags that rely on ambient signals minimize maintenance, cost and operation and open the possibility to increase the life span of the RFID reader battery. AmBC is different from traditional backscatter radio communication because it involves only the reverse link for describing the backscatter communication hence reducing on the analyzed read range limitations and power wasted in the forward link. Traditional backscatter communication involves two distinct links; the forward link for powering the RFID tags and the reverse link that describes backscatter communication and has both tag and reader parameters that limit the read range. The reverse link and forward link are examined in determining the power received by the tag; power backscattered to the reader and the operational range of the Passive ultra-high frequency (UHF) RFID systems. Factors such as tag sensitivity, RFID reader sensitivity and propagation environment are important parameters to consider in the limitation of the backscatter communication. We used mathematical equations in matrix laboratory (MATLAB) to obtain the possible distance of coverage from the ambient energy backscattered by the tag and the energy incident by the RFID reader. The costs to maintain the same distance for both forward and reverse link were determined.