Integration of electromagnetic and circuit analyses for the modeling of spatially distributed microwave and millimeterwave circuits, requires establishment of compatible ports which are defined in both the circuit and the electromagnetic realms. Four techniques are developed here and contrasted for the extraction of the port network parameters at circuit compatible ports. The network parameters are extracted directly from the Method of Moments impedance matrix. I. Introduction The Method of Moments (MoM) is an e#cient way of electromagnetically modeling structures as pre-analysis, embedded in the Green's function, is used to reduce the numerical computation that would otherwise be required in more general techniques such as Finite Element Method (FEM) or Finite Di#erence Method (FDM). This is especially true for antennas and open structures . As subdomain current basis functions and di#erential (or delta-gap) voltages are used in MoM formulation, the compatibility with general purpo..