Consistency Analysis of S-parameter Indirect Measurement for Improving Estimation Result

A consistency analysis procedure for our previously proposed indirect measurement method for the S-parameters of a multiport reciprocal circuit (e.g. bundle of wires or PCB traces) is proposed. In the measurement method, half of the ports are connected with some known loads and the remaining ports are directly measured by changing the load values to estimate the whole S-matrix. Some linear relations in the transfer coefficient submatrices between the direct and indirect measured ports have been used in the method. Those relations are selected to analyze the consistencies of the method from the theoretical viewpoint.Then, the indirect measurement method is applied to an example target, fixtures to measure the characteristics of wire-harness mounted in a vehicle, to evaluate the consistencies in the calculation process. Also, a method to obtain an improved estimation result using the consistency evaluation is provided.