Research of axially magnetized and shielded multilayered ferrite-dielectric radial waveguides

E. A. Mikhalitsyn – Post-graduate Student of Department of Physics and Technology of Optical Communication, Nizhny Novgorod State Technical University n.a. R.E. Alekseev; Research Engineer 3rd cat., FSUE FRPC “Measuring System Research Institute n.a. Yu.Ye. Sedakov” (Nizhny Novgorod). E-mail: mihalitsynea@gmail.com A. S. Raevsky – Dr.Sc. (Phys.-Math.), Professor, Head of Department of Physics and Technology of Optical Communication, Nizhny Novgorod State Technical University n.a. R.E. Alekseev. E-mail: raevsky@nntu.nnov.ru A. Yu. Sedakov – Dr.Sc. (Eng.), Associate Professor, Professor of Department of Physics and Technology of Optical Communication, Nizhny Novgorod State Technical University n.a. R.E. Alekseev; Director of FSUE FRPC “Measuring System Research Institute n.a. Yu.Ye. Sedakov” (Nizhny Novgorod). E-mail: niiis@niiis.nnov.ru

The eigenwaves discrete spectrum of multilayered anisotropic gyrodielectric radial waveguides is researched in the paper. Magnetic and dielectric mediums’ constants are considered as a second-rank tensors. The decision of the boundary problem is carried out by modes matching method. Maxwell\'s equations for the complex amplitudes of the electromagnetic field components converted to a generalized Helmholtz equation in a gyrotropic medium are solved with the use of L-method. The method consists in procedure of variables separation in which all the longitudinal components of the electromagnetic field have the same dependence on the transverse coordinates and vary depending on the longitudinal coordinate presentation. As a result, the longitudinal coordinate dependence of azimuthally field components is represented as a linear combination of four harmonic functions two of them have different longitudinal propagation constants and the others are just shifted with a phase π /2. The dispersion equation of eigenwaves for a multilayered gyrodielectric radial waveguide is obtained by an algebraization procedure of boundary conditions for the electric and magnetic azimuthally components on the every boundary between adjacent layers. As a result, the dependence of the radial component of the field is eliminated and the eigenwaves dispersion equation is written as the zero equaling determinant of algebraic equations system. The linear equations system is convenient represented in block-matrix form. All block-matrix elements have 2x2 dimension. The appropriate block-matrix elements for dielectric layers are diagonal. For the determinant order reduction, expression of amplitude coefficients of field expansion in the every layer through the coefficients of the previous one is used starting from the second layer. Eventually of successive substitution these expressions from one in another, the transcendental equation in the form of determinant of square second order matrix is obtained. The resulting transcendental equation is solved in regard to a transverse propagation constant. The calculation results and eigenwaves discrete spectrum analysis are provided for the multilayered gyrodielectric radial waveguides, which are so important in practice. Firstly, dielectric-ferrite-dielectric radial waveguide is analyzed. The main property of the hybrid doublet eigenwaves of guiding structure with gyrolayers consists in the splitting of dispersion characteristics to concern to the dispersion characteristics of appropriate dielectric radial waveguide. The dispersion characteristics of unsymmetrical radial waveguide modes don’t have intersection points because of eigenwaves aren’t energetically orthogonal. Secondly, the research of ferrite-dielectric-ferrite radial waveguide eigenwaves spectrum is carried out with the fixed value of per-meability tensor nondiagonal element and with frequency dependence of magnetic permeability tensor components defined by the Landau–Lifshitz model of the saturated ferrite with zero and nonzero magnetic bias field. Thirdly, the eigenwaves discrete spectrum analysis of the double-layered ferrite-dielectric radial waveguide is performed with longitu-dinal inhomogeneous internal magnetic state of ferrite. The comparison of two methods’ efficiency of ferrite layer stratification is carried out.