Representation of linear passive noisy 1-ports by two correlated noise sources
A.G. van Nie · Proceedings of the IEEE · 1972
The noise properties of a linear passive time-invariant 1-port can be described by two correlated noise sources such that the noise current through the real part of the admittance of the 1-port is independent of the external circuit, assuming thermal equilibrium. This theorem can be used for describing the noise performance of linearized detector circuits.