Analyses of Whispering Gallery Modes in Circular Resonators by Transmission Line Theory

Whispering gallery modes (WGMs) in circular resonators are investigated. Conformal transformation is used to transform circular resonators to more simplified structures. The principle of transverse resonance is utilized to calculate the resonant frequencies. Transmission line theory is applied to calculate the fields of electromagnetic waves. The resonant frequencies and field distributions in different high-Q resonators, including small resonators of several micrometers and large resonators of several millimeters in diameters, are investigated. The method provides a more efficient way to analyze the devices incorporating circular resonators.