Investigation of UHF power flow in the vicinity of a steel I-beam for optimization of its health monitoring using wireless sensor integrated RFID tag antenna system

In this paper the results of investigation of ultrahigh frequency power density in the vicinity of a steel I-beam using radio frequency identification (RFID) antenna system are presented. Simulation results show that the I-beam has different influence upon the amount power of incident on a tag antenna on its different locations along the beam. Furthermore, they show that suitably designed tag antennas can increase the power density in their locations in the inner surface of the I-beam. The measurement and simulation results are in good agreement. These findings have important implications for infrastructure health monitoring of complex-shaped structures using passive or semi-passive RFID-based sensory systems.