Open Hemispherical Imaging Dielectric Resonator with Whispering Gallery Modes

The imaging dielectric resonators with whispering gallery modes (WGMs) for the creation of a new class of millimeter wave solid-state oscillators, devices for the investigation of high temperature superconductors, were suggested. They contain a dielectric element as a semidisk or a cylinder or a hemisphere and a flat metal mirror. The latter is a necessary element for placing in the resonator field active elements or conductor samples of materials. There is an important question about the dependence of the resonant frequencies and Q-factor of these resonators on impedance of the resonator mirror. In the present paper new investigation results of the open hemispherical imaging dielectric resonator (HIDR) with WGMs are represented

Whispering-Gallery Modes in Shielded Hemispherical Dielectric Resonators

The results of the numerical and experimental investigations of whispering-gallery (WG) modes in shielded hemispherical dielectric resonators are presented in this paper. It is shown that the Q factor of WG modes in the shielded resonator can be ten times much higher than the Q factor of the similar open hemispherical dielectric-resonator modes. Shielding the resonator can decrease the dimensions of both the dielectric hemisphere and resonator as a whole, saving the high-Q factor of WG modes. The usage of a cylindrical shield and local flat reflectors in the experiment provides the investigation of the high-Q factor of WG modes in the resonator

About Resonant Modes at the Shielded Dielectric Hemisphere

The resonant modes, which are excited at the shielded dielectric hemisphere, are investigated by the theoretical and experimental methods. The low-Q-factor modes of air cavity and high-Q-factor whispering gallery modes of dielectric structure are existed together in the case of high radial index value. The Q-factor value of the whispering gallery modes of the shielded dielectric sphere with the certain correlation between the sizes of dielectric hemisphere and metal shield can be more great than the Q-factor of the whispering gallery modes of the similar open dielectric resonator