A. E. Kogut

Whispering gallery modes induced in a partly shielded hemispherical dielectric resonator

Whispering gallery modes induced in a partly shielded hemispherical dielectric resonator by lumped radiation sources were experimentally studied for the symmetric and asymmetric arrangement of the hemisphere relative to the cylindrical metal shield. The oscillation mode characteristics are presented for the shielded hemispherical resonator and an analogous open dielectric resonator. The proposed resonator is a promising device for the creation of highly stable solid-state millimetric wave oscillators.

Millimeter-wave whispering gallery modes in an ellipsoidal dielectric resonator with a small ellipticity

It is found that, when the shape of a dielectric sphere (hemisphere) operating under the whispering gallery mode conditions is perturbed by a surface curvature gradient (ellipticity), the unloaded Q factor of the sphere degrades and its resonance frequencies change. It is shown theoretically and experimentally that an elliptic irregularity removes frequency degeneracy of whispering gallery modes at millimeter waves.

High-Q whispering-gallery oscillations in a shielded spherical dielectric cavity

Results are presented of theoretical and experimental investigations of whispering-gallery oscillations in a shielded isotropic layered spherical dielectric cavity. Oscillations whose Q factor is two orders of magnitude higher than that of the oscillations of an open dielectric sphere are studied. Intermode interaction is observed between various cavity oscillation modes.

Dielectrometer measuring cell for investigation of liquids with high losses and high dielectric constant designed in form of the two - layer semispherical Teflon resonator

During the last time open dielectric resonators (DR) excited on whispering-gallery type waves due to their high Q-factor on the higher modes are used to investigate the dielectric properties of not only solid substances but also of liquids. For these purposes in the first experiments DR (which was used as measuring cell) being immersed directly in tested liquid. The investigated liquid influenced on external caustic of DR that led to frequency sift and changes of resonator Q factor. New achievement in creation of the dielectrometer measuring cells have appeared after the creation of the resonant structures in which certain geometrical parts of resonators are used. At first, such DR were created with metal mirrors. The subsequent researches [1] have shown that oscillations exist also without a mirror, which itself leads to condensate of a spectrum and reduction of the quality of resonator.

Hemispherical dielectric resonator with concentric hemispherical hollow for liquid dielectrics investigations

A new measuring cell is suggested in order to investigate dielectric properties of liquids with great losses.

Peculiarities of the excitation of whispering gallery waves in the hemispherical dielectric resonator

The carried out investigations of the whispering gallery mode fields in a hemisphere by a local radiant arranged on a mirror and, not having central symmetry, have shown an opportunity of preferred excitation of waves of one type E or H. It allows a little to rarefy a spectrum of excited oscillations, having restricted one of the modes, and more effectively to use a resonance-frequency behaviour of a hemisphere as resonant system.

Effect of the ellipticity of a dielectric resonator on the induced whispering gallery modes

The influence of ellipticity of a dielectric resonator on the whispering gallery (WG) oscillation modes induced by a lumped radiation source was studied. Dependence of the spectral characteristics of resonators and the spatial distributions of oscillation fields on the WG mode propagation direction is experimentally determined.