RT Journal Article
ID 3482278915a59b3d
A1 Skresanov, V. N.
A1 Glamazdin, V. V.
T1 Q-FACTOR MEASUREMENTS UNDER CONDITIONS OF CLOSELY-SPACED RESONANT FREQUENCIES OF MODES IN OPEN RESONATORS
JF Telecommunications and Radio Engineering
JO TRE
YR 2016
FD 2016-08-16
VO 75
IS 10
SP 867
OP 886
K1 Q-factor measurement
K1 amplitude-frequency characteristic
K1 open resonator
K1 linear-fractional approximation
K1 open resonator impedance
AB A method is suggested for measuring Q-factors of microwave resonators. The technique enables investigating properties of materials and media using open resonators of various types in the presence of modes with closely-separated frequencies in the vicinity of the selected oscillation mode, radiation loss of the coupling elements and cross-talk interference between them. The measurement of the loaded Q-factor is based on representation of the frequency dependence of the complex-valued reflection or transmission factor by a sum of homographic complex-valued functions which describe responses of individual modes, and approximation of the square of the measured amplitude-frequency characteristic using the variational gradient technique. The method of estimating the intrinsic Q-factor is based on calculating the resonator impedance using the measured magnitude of the reflection factor. The developed algorithms have been implemented as a computer program and analyzed using an example of processing of frequency dependences of the S-parameters of a mirror dielectric open resonator supporting the whispering-gallery modes. At that the S-parameters have been calculated by the finite-element method. The technique suggested for measuring the Q-factors is free of the systematic measurement error associated with distortions of the resonance curves and makes it possible to perform measurement under conditions when the classical methods break fail.
PB Begell House
LK http://dl.begellhouse.com/journals/0632a9d54950b268,3b017e1965aab5e1,3482278915a59b3d.html