Optimization of a High Frequency Radio Frequency Identification System for Tool Recognition in a Metal Environment

In this work an identification system based on near field communication is designed and simulated. A scenario is investigated, where the exchange of a sensor in a measurement device shall be recognized by means of Radio Frequency Identification. The system is especially challenging, because it comprises a metallic environment and the orientation of transponder and reader antenna may be unfavorable. In this work a system optimization based on the evaluation of magnetic field simulations is performed. Whereby, the whole environment is included. In order to improve the system's performance in the close vicinity of metals, a ferrite is used. For the present scenario the placement of ferrite sheets above and below the transponder at certain positions is found to efficiently improve the systems reliability. Simulations show that a magnetic field strength of greater than 25 A/m can be achieved by a 200 mW reader at the transponder for all investigated sensor orientations, which allows a successful readout of the tag.