Evaluation of performance of UHF passive RFID system in metal and liquid environment

The objective of the proposed work is to observe the changes in the performance of passive ultra high frequency (UHF) radio frequency identification system (RFID) when it was placed closer to several types of metals present in industries and water. The change in performance of the RFID reader was calculated in terms of change in number of tag reads per second and the change in read distance between tag and reader. In order to observe these effects in real time environment, we have considered five numbers of metals with different material characteristics and potable water with less salt content were undertaken for this study. We conducted the experiments in room which is partially shielded from interferences of any type. The tags were fixed in different materials at its centre and kept at different distances from RFID reader antenna. At each distance, the performance of the RFID reader was measured. We also conducted the tests to verify the whether the tag was read when it was fixed on water container. From the results obtained, we found that the performance of the UHF RFID system was not affected when they were closer to the certain types of metals we tested and water.