Methodology of elementary negative group delay active topologies identification

This work introduces a fundamental methodology enabling to identify the elementary negative group delay (NGD) topologies using transistors. These circuits are particularly beneficial compared to the other existing NGD topologies, with its flexibility to operate in ultra wideband (UWB), to compensate losses and potentially integrable. The basic families of NGD topologies obtained from the association of passive and active four-port networks are presented. The NGD existence condition is given. Based on this condition, the simplest NGD active cells are identified. After the analysis of passive networks formed by R, L and C components, first-order transfer functions of innovative elementary NGD cells are established. Then, similar to the classical circuits as the filters and amplifiers, synthesis relations for the design of integrable NGD topology with no self-element are introduced. To illustrate the relevance of the theoretic concept, a proof of concept was proposed. Finally, discussions on the applications of NGD circuits are offered in the conclusion.