Gaining advanced insight in the phase stability of comb generators using a Large-Signal Network Analyzer

Phase reference elements are essential to the calibration and performance verification of large-signal network analyzers (LSNA). These elements are assumed to generate a very well known reference signal and as such need to be very stable in phase. This paper shows how the LSNA can be used to investigate their phase stability and sensitivity. Different aspects need to be studied: stability against time, sensitivity with respect to temperature, sensitivity related to input power variations, sensitivity to fundamental and harmonic terminations, influence of harmonic distortion of the excitation source and sensitivity for harmonic input impedance variation. All these aspects can be analyzed efficiently with a large-signal network analyzer gaining advanced insight in the phase stability of phase reference elements.