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How to extract distributed circuit parameters from the scattering parameters of a transmission line



Nathan D. Orloff, Jasper A. Drisko, Angela C. Stelson, Charles A. Little, James C. Booth, Jordi Mateu, Christian J. Long


Distributed circuit parameters parameterize the transmission and reflection off a given transmission line in terms of a distributed resistance, inductance, capacitance, and conductance, which are per unit length frequency dependent quantities. While there are analytical models for extracting the distributed circuit parameters, these models are discontinuous as a function of frequency when the phases of the transmission or reflection approach π or -π. Here, we develop a nonlinear least-square regression algorithm that accurately extracts the distributed circuit parameters. Compared to existing approaches and finite element models, our algorithm successfully extracts the distributed circuit parameters as a function of frequency; all while being less sensitive to these phase conditions. Such an algorithm is useful for understanding how to deembed transmission lines, and how to extract electrical properties of the materials used in a circuit.
Conference Dates
November 28-December 1, 2017
Conference Location
Boulder, CO
Conference Title
90th ARFTG Microwave Measurement Conference


transmission line, fitting, distributed circuit parameters, S-parameters.


Orloff, N. , Drisko, J. , Stelson, A. , Little, C. , Booth, J. , Mateu, J. and Long, C. (2018), How to extract distributed circuit parameters from the scattering parameters of a transmission line, 90th ARFTG Microwave Measurement Conference, Boulder, CO, [online], (Accessed July 23, 2024)


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Created January 15, 2018, Updated January 27, 2020