Excitation of the high-Q-factor whispering gallery modes in the hemispherical dielectric resonator with the cylinder shield

A hollow metal cylinder with a semicircle in the base is used as the shield of a hemispherical dielectric resonator with whispering gallery (WG) modes. It is shown that the spectrum of the WG modes of this resonator is clearer than the spectrum of a similar resonator with a hemispherical shield. It is determined that the high-Q-factor WG modes are excited in the proposed resonator by the coupling slot on the mirror. Their fields are localized in the dielectric. The frequency dependence of the Q-factor value is measured. A good conformity of this experimental dependence with the analytic dependence is obtained in this paper.