On the Efficiency of Load Modulation in RFID Systems Operating in Real Environment

The performance of UHF-RFID systems are particularly exposed to environmental effects, such as multipath propagation and electromagnetic coupling. This sensitivity to the electromagnetic properties of the environment is peculiar of systems operating in the UHF band and therefore has not been completely investigated, since many RFID systems still work at HF frequencies. In this letter, the possible impairments due to the most usual environmental effects are considered, with particular reference to the impact on the bit error rate (BER) at the reader side in the Uplink stage of the RFID system.