Normalized power calculation to UHF RFID passive tags characterization

This paper describes a new method to characterize commercial UHF RFID passive tags in the near-field and far-field zones of the reader antenna. This method is based on the tag´s performance on power activation in several distances. Different kind of commercial tags were performed, and from measurements results, the normalized power calculation is introduced in order to investigate the evolution of power requirements to activate the tag in the near and far field regions. According to tag´s antenna geometric features and the normalized power result of each one it is possible to classify the tag in two different families.