The Complete and Accurate Determination of Two-Port Noise Parameters without Seperate Measurements of the Two-Port Input Impedance

Improvements in the determination of the 4 real parameters Fmin, Rn, Gopt Bopt which completely describe the noise behaviour of a linear two-port are presented. The state of the art theory of noise parameter measurement is based on measurements of the noise figure Fi of the device under test for a number of different noise sources i. Finally, partially nonlinear relations lead to the measurement result for Fmin, Rn, Gopt, Bopt. The straightforward approach presented in this paper combines in a more direct manner, measurements of noise power to a set of linear equations, the solution of which are the noise parameters of the device under test. Contrary to previous works, our theory inherently allows to determine the input impedance of the unkown two-port. Hitherto, this impedance must be measured by means of a seperate impedance measurement.