S-parameter estimation for a multiport connection and a multiport device with non-common ground

An estimation method is presented for the S-parameters of both a multiport connection and a multiport device. The multiport device is connected to the output end of the multiport connection and a network analyzer is connected to its input end. Here, the multiport device and the input end of the connection are assumed to have different ground levels. Only measurements of reflection and transmission characteristics among the ports of input end of the connection are required for the estimation. Both S-parameters are estimated by solving several linear equations and quadratic equations only. The validity of the proposed method is also confirmed by simple experimental results.