Shielded dielectric resonators

The resonances of a dielectric stub in a waveguide shield are considered as coupled modes. The transition of cavity modes to dielectric resonances and vice versa is shown for the TM(011) modes. It is shown that the coupling constant can be estimated from an electrostatic consideration of the 'series connection' of electric fields in the dielectric resonator and in the air-filled cavity. Reference is made to a study by Hong and Jansen (1982) in which the resonance frequencies of dielectric disk resonators in a cylindrical waveguide shield were calculated exactly using the mode-matching procedure. It is pointed out, however, that the nomenclature must still be clarified. The dielectric disk and the waveguide cavity represent coupled resonators (coupled by means of common field components) exhibiting the characteristic dispersion behavior of coupled modes.