Analysis of cylindrical cavities to measure accurate relative permittivity and permeability of rod samples

A measurement method using the TM₀₁₀ and TM₀₁₁ mode cylindrical cavity is proposed to measure the accurate relative permittivity ε_r and permeability μ_r of ferrite materials. The method is based on the rigorous electromagnetic field analysis using the Ritz-Galerkin method to take into account the effects of the sample insertion holes of a cavity and the material parameters ε_r and μ_r. Numerical calculations were performed for a cavity structure used in our experiments. The cavity dimensions were measured rigorously for the TM and TE mode cavity before ε_r and μ_r measurements. The measurement results of a fused quartz and a ferrite sample show the validity of the analysis of TM and TE mode cavity.