HF RFID Readerfor Mouse Identification - Study of Magnetic Coupling between Multi-Antennas and a Ferrite Transponder

Abstract

This paper depicts an optimized RFID system operating at 13.56 MHz, used to recognize a mouse. When it passes near an antenna, the small transponder (1x6 mm) placed in its body communicates with the antenna. The distance of communication is small (around 3 centimeters) and our objective was to increase this distance. The transponder receives the signal from a coil wound around a magnetic circuit. The characteristics of the ferrite are very important for the communication. All the elements of the chain are taken into account in ADS simulation and we determine the value of the minimum voltage necessary for remote bias. Finite-element analysis is employed to extract the values of the generated magnetic field. The paper shows how to correlate the influent parameters to increase the communication distance. To improve this reading rate, a novel differential receiving antenna has been designed allowing an improved decoupling with the close transmitting antenna. An electrical model of the different parts has been performed. This includes the tag, the reader antennas and the coupling between them. These models have been validated by measurements and used for the simulations of the complete system.