Magnetic near Field Investigation and Shielding Effectiveness Evaluation of an Inductive Power Transfer System with a Resonator Array

This paper presents a study of the magnetic near field produced by an inductive power transfer (IPT) system composed of an array of magnetically coupled resonators that may be embedded in a table for powering desktop electronic devices. The analysis is performed considering different positions of the receiver circuit, namely different structures of the system, that lead to very different behaviour in terms of the generated magnetic field. Significant peaks of the magnetic field have been detected in correspondence of certain resonators of the array for different positions of the receiver, thereby making shield actions necessary. An estimation of the shielding effectiveness of a shield used to reduce human exposure to the generated magnetic field is carried out. The theoretical results have been validated with experimental measurements.