FDTD analysis of platform effect reduction with thin film ferrite

Conformal antennas suffer from the platform effect on which the radiation of the current become inefficient due to the existence of the image current in the opposite direction. The platform effect may be well shielded with thin film ferrimagnetic material that has a high in-plane permeability. A one-dimensional finite difference time domain method (1-D FDTD) is developed to model the current radiations off the thin-film ferrite coated ground plane. Both the ferromagnetic resonances (FMR) of the ferrite and the radiation of electromagnetic wave caused by the dynamic magnetic field are simulated, by solving Landau-Lifshitz-Gilbert (LLG) equation and Maxwell's equations simultaneously. The simulated relative permeability curve matches with the theoretical results. Radiated power is computed as well, which increases as the thickness of the film increases or the FMR line width of the material susceptibility decreases.