On the concretely passive realization of reduced circuit models based on convex constrained positive real fractions identification

The paper deals with the problem of concretely passive realizations of reduced models directly associated to Foster (matrix) expansions. After considering the procedure named Positive Fraction Vector Fitting (PFVF), based on convex passive constrained optimization applied to a pole-residue scheme identification, we will show how such formulation allows unique and straightforward possibility of concretely passive realizations, by means of generalized Foster matrices. This remarkable property, not common to other passive macromodeling techniques, complements the already known favorable aspects of PFVF with a straightforward possibility of a purely passive elements circuit realization.