Movchan M. Electromagnetic oscillations in composite gyrotropic resonators

This thesis is devoted to the theoretical and experimental investigation of the electromagnetic oscillations in the composite gyrotropic microwave resonators and the application of the magnetodynamical oscillations (MDO) in the ferrite resonators (FR) for construction of passive microwave devices for millimeter waveband on the ground of the new physical principles. The theory of MDO in the cylinder-shaped gyrotropic resonators has been developed. MDO in FR made from barium hexaferrite (BaM) have been investigated theoretically and experimentally in below the ferromagnetic resonance region. The existence of bias field range was shown where the resonator made from BaM demonstrates phase-frequency bistability effect. It was shown, that the predominant cause of the initial splitting of the magnetodynamic oscillations' eigenfrequencies in FR is the influence of the side walls of the rectangular waveguide. Dual electric and magnetic fields tuning of coupled magnetopolariton oscillations in the composite resonator has been proposed and investigated by means of dual tuning of the magnetostatic resonator, which enter into the composite resonator.