Impact of RF interference between a passive RFID system and a frequency hopping communications system in the 900 MHz ISM band

We present experimental measurements and analysis of RF interference between a passive RFID system and a generic frequency hopping communications system in the 902 MHz to 928 MHz ISM radio band. Interference in both directions is considered, RFID to communications and vice-versa, and interference mitigation strategies are assessed. Variables of interest include transmission power, antenna locations and polarization, and frequency hopping channel bandwidth and dwell time. Among the findings are the susceptibility of the RFID backscatter link to sources operating within regulatory limits, characterization of the performance asymmetry between the systems, and the constructive effect of interference to RFID at low powers.