Comparison of noise-parameter measurement strategies: Simulation results for amplifiers

A previously developed simulator for noise-parameter measurements has been used in an extensive investigation and comparison of different measurement strategies for measuring the noise parameters of low-noise amplifiers (LNAs). This paper summarizes the methodology and reports the salient results of that investigation. The simulator is based on a Monte Carlo program for noise-parameter uncertainties and enables us to compare the uncertainties (both type A and type B) obtained with a given set of input terminations. We focus on results that do not depend (or depend only weakly) on details of the device under test (DUT). One noteworthy result is the marked improvement in the noise-parameter measurement uncertainties when a matched, cold (i.e., well below ambient noise temperature) source is included in the set of input terminations.