EC Model for WPT and NFC Systems Interoperability Analysis

In this paper, we present a novel equivalent circuit (EC) model that can be used to conduct a circuit-level interoperability analysis of a wireless power transfer (WPT) system and a near-field communication (NFC) system in close proximity to one another. Each system consists of two devices, which are respectively the WPT transmitter, WPT receiver, NFC reader, and NFC transponder (tag). Due to their close proximity, the WPT and the NFC systems interact with one another due to parasitic inductive and capacitive coupling between their coil antennas. Our investigations show that parasitic coupling causes the NFC system to produce a distorted communication signal. In particular, the detectability of the communication signal sent from the NFC tag to the NFC reader decreases rapidly, if the parasitic capacitive coupling between the coil antennas is too large. In addition, a custom-built prototype is presented here that can be used to take measurements and verify these results.