Linear networks as Möbius transformations and their invariance properties
Tullio E. Rozzi, J.H.C. van Heuven, Alan S. Meyer · Proceedings of the IEEE · 1971
Using the properties of the Möbius transformation, the most general conditions necessary for the transforming network can be found for the existence of the Q factor for a two-state one-port network. Other figures of merit can be found for two-state and one-state terminations with different classes of transforming networks.