HF coils design and shielding for a medical monitoring patch

In this paper, we present the shielding of a medical patch, used in near-field coupling technology (13.56 MHz). The designed coil is used for powering, by inductive coupling, the electronic part of the battery-less patch. Different methods of shielding with minimum ferrite (from 0.1 to 0.3 mm) and metal thicknesses, are simulated. Measurements results are given concerning the realization of the coil optimal shielding, and an approximation of the shielding effectiveness is presented as a figure of merit. The use of a NXP Ntag chip is considered for the patch realization.