Fig. 4. The measured power gain and compression of the amplifier. (a) GP with minimum and maximum uncertainty limits. The measurement uncertainty in GP 0.16 dB. The uncertainty in P1dB at different PIN (-15 dBm (blue) to +5 dBm (purple) in 2 dB steps); (b) P1dB of the amplifier is between 0.1 and and u(P1dB) is around 0.03 dB larger than u(GP 0.06 dB larger than u(PIN is between 0.12 and 0.18 dB ) and about ). It should be noted that the step in uncertainty at 5 GHz is mainly due to a change if the value of uncertainty in the power meter, as specified by the manufacturer. Fig. 5b shows the measurement uncertainty in the analysed amplifier parameters plotted against PIN at 5 GHz. Discussion of Results In our experiment, the uncertainties in the amplifier 's small-signal parameters, which were characterized using Sparameters, are due to the calibration standards, electrical noise, cable flexing and connector repeatability. The measurement results show typical uncertainties that can be expected from such measurements. The large-signal parameters include an additional source of uncertainty from the power meter. The uncertainties from Fig. 5. Measurement uncertainties for different large-signal parameters of the amplifier. (a) Uncertainty plotted against frequency; (b) Uncertainty plotted against PIN at 5 GHz. 42 IEEE Instrumentation & Measurement Magazine September 2022