Test results for HF RFID Antenna system tuning in metal environment

Operation of RFID systems is strongly disturbed by metallic environments in the proximity of the antenna. These environments produce a detuning on the antenna, which as a side effect produce a drastic decrease in reading distance. In this paper, the authors show that it's possible to make a radical improvement on HF RFID systems performances by retuning the reader antenna to its system working frequency. In this way it's shown that HF RFID systems can work well in the proximity of metallic environments with the small price in the decreasing of the reading distance. Comparative test results are presented in this paper for the HF RFID system in the close proximity of metallic environments and in its absences. The most important parameters for this system that are evaluated are resonance frequency and reading distance.