Characterization techniques for stability and noise in microwave amplifiers under large-signal excitations

In this paper, two characterization approaches for electrical noise and stability in microwave amplifiers operating in large-signal regimes are reviewed. The first technique concerns the experimental determination of amplifier stability margins through pole-zero analysis of measured closed-loop frequency responses. The second technique deals with the measurement of AM and PM amplifier noise in non-linear regime and outlines the main differences with the linear case.