Identification of non-common node ports

A procedure is presented for identifying the noncommon node ports of an n-port single-element type network. The technique eliminates some of the nonrealizable port structures in an (n+ p)-mode network synthesis without going into the actual realization procedure. It also gives additional information regarding the location of the augmented port. The method is based on the fact that the polarity of the voltage (or the direction of the current) at the response port is independent of both the short or the open-circuit conditions of all other ports when the source and response ports have a common node