Abstract

Four parameters are necessary for a complete characterization of the noise behavior of a linear device.The parameters can be experimentally determined by a minimum set of four equations,which can be obtained by an equal number of synthesized reflection coefficients at the input of the DUT,forming a pattern on the Smith chart.To increase the accuracy in the determination of the noise parameters,it is a common procedure to implement an heavily redundant pattern,with a random selection of more than the strictly necessary four points,so forcing the adoption of an expensive tuner.This paper introduces a novel ad hoc selected 4-points pattern,and demonstrates how it can simplify the measurement system without appreciably affecting the measurement accuracy.The proposed pattern is synthesized by easily realizable transmission lines,and a study has been performed to determine lines characteristics for use in wideband noise measurements.