Finite energy networks

The class of nonenergetic n ports, i.e., those n ports that have at most finite energy gain, are studied in a scattering theoretic context. The properties of such ports are shown to extend naturally those of passive n ports, and a number results on passive n ports, including the theorem of Youla, Castriota, and Carlin concerning the relationship between passivity and causality, are extended to the nonenergetic case.