Design of a Faraday cage for biomedical measurements based on site electromagnetic field mapping

Abstract

A Faraday cage is an electromagnetic enclosure that is characterized by keeping inside the electric field constant if a nonzero electric charge is applied. On other hand, if the electric charge is zero, the electric field will also be zero. A Faraday cage design is presented for biomedical measurements to operate at 206 MHz with and without electromagnetic absorbents. The design was based on an electromagnetic field mapping to identify the potential sources of electromagnetic interference, their wavelength, effectiveness shielding and therefore, the physical dimensions of the enclosure. Subsequently, a computer simulation using finite element method was executed for the designed enclosure. Once both simulations were performed it was found that without absorbents, the current density was lower than in the simulation with absorbents. On the other hand, the radiation pattern with absorbents was lower in than the simulation without absorbents.