2-D And 3-D Numerical Simulation of Ferrite Loaded Coaxial Transmission Lines

Coaxial transmission lines filled with saturated ferromagnetic material have been used for pulse sharpening purposes and high-frequency oscillation generation for a long time. These phenomena have been well studied experimentally, but have no exact analytical description; simplified models provide only qualitative agreement with the experiment. For quantitative description, it is necessary to solve Maxwell equations together with Landau-Lifshitz equation for the magnetization vector. The paper presents numerical simulation of high-voltage pulse sharpening process and excitation of high-frequency oscillations in coaxial lines filled with saturated ferrite. The modeling was performed using the KARAT code in three versions: axisymmetric (RZ) and three-dimensional Cartesian (XYZ) and cylindrical ( $\mathrm{R}\Theta\mathrm{Z}$ ). The results are compared with previous experiments.