EMC and EMI issues of WPT systems for wearable and implantable devices

This paper discusses the electromagnetic compatibility and interference aspects related to wireless power transfer (WPT) systems for wearable and implantable devices. The cases of a near-field (reactive) link for recharging a pacemaker and a far-field (radiative) link for wearable devices are considered. For the first case a design approach, able to perform efficient energy transfer under the safety regulations constraints of medical devices is proposed. In the second case, a rigorous methodology is proposed to predict the transferred energy to a worn device able to account for interferences due to the human body or any other wireless system located close to the worn device. An implementation of grounded worn rectennas in the presence of unconventional radio channels is presented.