Characterization of a UHF RFID chip

A key aspect to improve the operating range in the manufacture of tags for UHF RFID systems is to achieve an effective adaptation between the impedance of antenna and chip. Due to the characteristics of the communication between reader and tag, UHF RFID integrated circuits present two operational states which have different impedances. Integrated circuits manufacturers only publish data about one of the states, namely the absorbing state. This paper introduces a procedure to characterize chip impedance thoroughly in both operational states and describes experimental results of Alien Higgs 4 commercial chip.