Numerical Simulation of EM Environment and Human Exposure When Using RFID Devices

In this work, RFID readers and active tags, operating at 2.4GHz and 5.8 GHz, are simulated to calculate the electromagnetic field distribution generated in their surroundings, considering the presence of the user’s body and possible scattering obstacles, and including the analysis of the specific absorption rate (SAR) in the human models (which can be very close to the tag). The finite-difference time-domain (FDTD) method and the finite elements (FE) method are used. Results show that significant field level can be found in regions far from the tag-reader direction. This fact could constitute a risk because of the possible presence of general public and eventual eavesdroppers. Nevertheless, the calculated values of SAR are always below the basic restrictions.