THEORETICAL AND EXPERIMENTAL INVESTIGATION OF FERRITE-LOADED WAVEGUIDE FOR FERRIMAGNETISM CHARACTERIZATION

This work proposes an approach to retrieve the ferrite’s electromagnetic properties in a single compact configuration, simpler than the traditional measurement systems. The ferrite under test is fully inserted into a rectangular waveguide with a magnetic bias. The complex scattering parameters are theoretically analyzed under the consideration of modal effect at isotropy-anisotropy interfaces. Extraordinarily sharp Fano resonances are observed in the scattering spectrums, originating from the multimode interference inside the magnetized ferrite. There is good agreement among theoretical, experimental, and full-wave simulation results. This model can be further utilized to simultaneously retrieve all ferrite properties, including permittivity (ε), saturation magnetization (4πMs), and magnetic linewidth (ΔH) from the measured scattering parameters, facilitating the designs and applications of ferrite devices.