design of an high frequency rfid multi-loop antenna for applications in metallic environments

Due to the fast growing of automatic processing in the majority of industrial applications, use of RFID technology is almost mandatory. These systems must identify, with high accuracy, objects placed at different angles or objects placed in harsh environments. In this paper, a new design of an HF RFID reader antenna is proposed, which uses a multi-loop configuration. This configuration ensures a uniform magnetic field on its entire surface, even if the antenna is placed on or very close to a metallic plane. The structure of the proposed antenna is mathematically modelled and computer simulated, as a proof of the concept, followed by a validation on an experimental prototype. Results confirm an increase of up to 9 times for the reading distance, compared with a standard HF RFID reader antenna, working in the same environment. The proposed model can be used in order to improve the accuracy of RFID tag identification in real life applications.