3D Finite-Difference Time-Domain (FDTD) Modeling of Nonlinear RF Thin Film Magnetic Devices
An unconditionally stable three-dimensional (3D) finite-difference time-domain (FDTD) algorithm has been proposed to predict the dynamic interaction between nonlinear magnetic spins and electromagnetic (EM) fields in nonlinear magnetic devices. The proposed modeling solves simultaneously Maxwell’s equations and the Landau-Lifshitz-Gilbert (LLG) equation with full nonlinear effects. The accuracy of the modeling has been validated by 1. Small signal simulation of a linear ferrite isolator and 2. Large signal simulation of the dispersive permeability of a continuous ferrite film. The simulations agree with the theoretical and experimental predictions. The fact that the 2-µm-thick film exhibits strong nonlinearity shows the potential of magnetic thin film applied in miniature RF front ends.