Design, modeling, and analysis of a novel 13.56 MHz RFID reader

In this paper, an overview of antenna design for passive radio frequency identification (RFID) tags is presented. Design, simulation and modeling of a 13.56 MHz RFID tag is provided. Also a matching network is designed for 50 ohms with a high quality factor. Simulation results of near-field strength versus frequency and distance are presented. It is shown that field strength reduces exponentially with distance and frequency. 3D and 2D far-field radiation patterns are presented at 13.56 MHz. Spurious radiations at 433 MHz band is also simulated and analyzed. It is demonstrated that loop antennas can work efficiently as an RFID tag given the right dimensions and matching network implementations. The antenna presented here has a planar structure, thus, integrable with RF circuits.