EM modeling of metal pipe based UHF RFID tags activated by R/W antenna

This paper presents the full-wave EM simulation and analysis of UHF RFID R/W antenna exciting the IC tag placed inside the coaxial metal pipe. The practical need for such a simulation model has followed the specific problem of activating the RFID tag being placed inside the hollow metal pipe. An original approach to match the characteristic impedance of the coaxial waveguide to that of the free space and to activate an IC tag installed inside the metal pipe will be explained. Various numerical data illustrating the mechanism of activating the IC tag inside the coaxial waveguide by incoming CP wave from the RFID R/W antenna will be presented.