Optimization of Q-factor and resonance frequency measurements in partially calibrated resonant systems

We present numerical and experimental results aimed at reducing the uncertainties in measurements of the quality factor and resonance frequency of microwave resonators. We focus on the optimization of the frequency span and on the role of uncalibrated transmission lines. We find that optimal frequency spans are different for measurements of the quality factor and of the resonance frequency. The uncertainty introduced by uncalibrated lines, unavoidable in particular kinds of measurements, is experimentally determined. We give practical indications on best compromises for a wide range of quality factors.