J. Krupka et al., STUDY OF WHISPERING-GALLERY MODES IN ANISOTROPIC SINGLE-CRYSTAL DIELECTRIC RESONATORS, IEEE transactions on microwave theory and techniques, 42(1), 1994, pp. 56-61
The Rayleigh-Ritz method and the finite element method nongenerating s
purious solutions are employed for analysis of whispering gallery mode
s (WGM's) in cylindrical single-crystal anisotropic dielectric resonat
ors. These methods allow accurate computation of the resonant frequenc
ies, the Q-factors (depending on the dielectric and on the conductor l
osses), and the electromagnetic field distributions for all WGM's in t
he presence of additional elements like metal shields, MIC substrate,
or supports. Different families of modes are studied both theoreticall
y and experimentally. The mode coupling phenomenon is investigated. A
WGM single-crystal quartz resonator is presented having an unloaded Q-
factor greater than 30000 at about 100 GHz, including radiation and di
electric losses.