DETERMINATION OF THE RESONANCE FREQUENCY AND THE Q-FACTOR OF A HALF-DISK DIELECTRIC RESONATOR USING FRACTIONAL RATIONAL APPROXIMATION

Abstract

The problems of determining the resonant frequency and the
Q-factor of whispering gallery type oscillations in a half-disk
dielectric resonator have been considered. The influence of violations
of the conditions of reciprocity, non-dissipative character,
symmetry for coupler of the resonator on its reflection
characteristic versus frequency are investigated. For mentioned
cases, the correctness of using classical methods of measuring
the resonator natural frequency and Q-factor of the resonator
has been analyzed. To solve this problem, the possibility of
using a fractionally rational approximation of the resonator
frequency response was discussed. The realization of the rational
approximation based on continued fractions is proposed
that allows obtaining stable estimates for evaluating the complex
frequency and Q-factor. The use of this approach has
allowed analyzing the dependence of the natural frequency of
the half-disk dielectric resonator versus degree of coupling which
is determined by radial location and width of the coupling slot.
It has been shown that the difference between the pole and
zero frequencies allows estimating the degree of coupling.