Sparse two-phase transmission line representation in phase-domain based on time-domain fitting

This work presents a methodology for deriving a sparse two-phase transmission line representation in the phase-domain based on time-domain fitting. The resulting model is described by a polynomial matrix in the z-domain. The robustness of the representation, i.e. stability and passivity, is attained by imbedding a set of constraints in the fitting equations which are solved using quadratic programming. Results demonstrating the features of the derived representation are presented for the case of an untransposed two-phase transmission line.