Interference Sources in Congested Environments and its Effects in UHF-RFID Systems: A Review

In scenario where radio frequency identification (RFID) readers become increasingly common in hand held devices, the radios are prone to several interferences not only from external radio sources but also from the plurality of portable devices that may become more common over time. For that reason it is of interest to well understand how these radio interferences may be influencing a UHF-RFID transceiver working according to EPCglobal Class-1 Gen-2. In particular, in this paper, the combination of interference coming from the self-radio, from other radio systems, such as mobile phone or other RFID reader, is analyzed, and such effects are combined with the appearance of multiple tag antennas interfering each other. A method based on simulation using tag antenna design is presented to evaluate inter-tag interference in a variety of cases. For a better understanding analytic examples are presented to compute such interference interactions within the RFID system.