An NFC air interface coupling model for contactless system performance estimation

The near-field communication channel is mainly determined by the coupling of two resonant loop antennas and their HF system properties. Such properties change dynamically during operation, affecting significantly power transfer and communication performance. Both these effects are related to an impedance mismatch which arises due to a varying coupling factor. In this paper we present a Matlab-based network simulation model which allows to estimate impedance and contactless performance aspects as a function of coupling, and to determine appropriate impedance matching and antenna design parameters.