Study of Mutual Coupling of Typical Commercial UHF RFID Tags in a High-Density Environment

In the context of high-density passive UHF (Ultra High Frequency) RFID (Radio Frequency Identification) tag technology, the problem of mutual coupling has to be taken into account as one of the performance criteria of UHF RFID systems. In practical applications, mutual coupling changes the intrinsic parameters of the antennas attached to these tags, i.e., the impedance matching of the antenna and the chip and the radiation pattern. The objective of this study is to study the performance of some commercial tag prototypes by their level of sensitivity to mutual coupling. The 3D initialization model of the Printed Dipole, Printed T-Match, and Printed Meander tags were used to directly extract the mutual impedance values in various scenarios by the ANSYS HFSS software and compare them with the MATLAB software. The simulated results show the effectiveness of this study in obtaining a clear understanding of the performance of the tags. These results open new perspectives on the study of mutual tag-to-tag coupling for research and will help users to make better decisions in the choice of UHF RFID tags for the radio frequency identification of products.