Numerical evaluation of the electric field induced in a cubic phantom by different antennas at 2.45 GHz

Previous studies evidenced that probes used to measure the electric field in the air are affected by an additional uncertainty, which increases as the field level grows, when measuring numerically modulated signals, such as those typical of the Wi-Fi standard at 2.45 GHz. To reliably evaluate the electromagnetic power absorbed by a body exposed to such signals, the behavior of the probes used for measuring the electric field inside biological media has to be characterized as well. To do this, one must have antennas able to induce high electric field values inside dissipative materials placed in the near field region. In this study numerical simulations have been carried out on two different antenna models (horn and loop) in order to evaluate the electric field distribution inside a cubic phantom. Results indicate that the printed loop antenna is more efficient than the horn one in inducing high values of electric field (tens of V/m) inside the phantom. Therefore, it can be efficiently used for the characterization of the electric field probes in the presence of digitally modulated signals at 2.45 GHz.