Cylindrical Waveguide on Ferrite Substrate Controlled by Externally Applied Magnetic Field

This paper presents an extension of the formulation of wave propagation in transverse electric (TE) and transverse magnetic (TM) modes for the case of metallic cylindrical waveguides filled with longitudinally magnetized ferrite. The higher order modes were exploited. We externally controlled the cut-off frequency through the application of DC magnetic fields. The numerical results of dispersion diagrams for TE and TM modes were obtained and analyzed. We analyzed a waveguide antenna filled with partially magnetized ferrite using the mode matching (MM) technique based on the TE and TM modes. By using modal analysis, our approach considerably reduced the computation time compared to HFSS. Ferrites are important for various industrial applications, such as circulators, isolators, antennas and filters.

Derivation of expressions of Faraday vectors excited by given sources in spherical coordinates from field expansion by TE- and TM-waves.

Formulas for electric and magnetic field strengths as sums of TE- and TM-modes in spherical coordinates excited by given volume electric and magnetic currents were derived. On the basis of them we obtained analytical formulas for field strengths in spiral basis excited by sources of circular polarization. From the known field strengths we derived and investigated formulas for Faraday vectors in spiral basis for waves of right and left circular polarizations. Pointing vector flows were calculated for waves of both circular polarizations. Obtained presentations for Faraday vectors and known results of other explorers are discussed.