Nonstationary network synthesis via state-space techniques
Steven I. Marcus, Jan C. Willems · IEEE Transactions on Circuits and Systems · 1975
A theory is developed for nonstationary network synthesis via state-space techniques. The method is based on direct realization algorithms from a Hankel matrix (input/output) description of the system. Passive, lossless, reciprocal, reversible, and relaxation systems are considered. For each of these classes of systems, necessary and sufficient conditions on the Hankel matrix for the existence of a representation which can be synthesized with certain types of network elements are derived. In addition, algorithms for computing these representations are presented.