UHF-RFID Read Range Characterization Method Using Power Activation Profiles

This paper presents a detailed characterization of passive UHF-RFID tags using measured power activation profiles. Factors such as chip sensitivity, antenna dimension, and conjugate impedance matching are taken into account. Results are presented in a proposed chart relating the square root of the modulation factor to the mean power transmission coefficient, providing a fine-grained comparison of tag performance. The free space read range of tags is then investigated as a function of mean transmission coefficient, modulation factor, chip and reader sensitivity. The approach is illustrated and validated through a measurement campaign on a set of 9 commercial tags. The proposed characterization procedure enables an accurate assessment of tag performance.