Explicit criterion for the stability of a linear active network containing transistors

The usual stability criteria do not enable the stability conditions to be taken into account in advance in the synthesis of a linear transistorised network. This disadvantage is removed by the method proposed in the paper, which gives the stability conditions directly as a function of the embedding passive network for the case in which ideal transistors, represented by nullors, are considered. This enables the designer to take into account the stability in advance, as shown by the application examples. Moreover, the criterion can be applied also to the synthetised network for testing the stability when the transistors are replaced by their complete equivalent circuits.