Noise parameter transformations of interconnected two-port networks

Calculations of noise parameters of interconnected two-port networks tend to be very lengthy. Furthermore the transformations are very involved which makes them hard to interpret. The paper presents a method by which these calculations may be simplified. By superposition the calculation is divided into two steps of which the second is independent of the type of interconnection involved. In this way only the first step of the calculation has to be performed when a new configuraltion is treated. The transformation is also more easily interpreted using this method, since the calculation is divided in a natural way. The paper starts by deriving formulas for the general second step in the admittance form of Rothe and Dahlke. The method is then applied to parallel and cascade connections. The series connection may be easily obtained as the dual form of the parallel case