Simplified equations of a 4-port scattering parameter model for characterizing 4-pair cabling systems of local area networks

This paper presents a set of simplified equations based on a 4-port scattering parameter (S-parameter) model for characterizing digital telecommunication cabling systems. These equations are simplified form multistage cascade S-parameter matrices. Excellent agreements between measurements and the computation results from the proposed equations with the S-parameters of components of a multistage cascaded cabling system are observed. These equations not only can reduce the computation burdens in comparison with traditional methods for S-matrix computations, but also can provide insights of the contributions of the S-parameters at each stage in the net crosstalk, return loss, and insertion loss of a cabling system. In addition, these equations can not only be used to compute the component specifications when the system performance is specified, but also can be used to obtain the de-embedded system characteristics by subtracting the known characteristic of the adapting components.