VNA error model conversion for N-port calibration comparison

This paper examines the extended 12-term error model commonly used in commercial multiport vector network analyzers, introduces a generalized multiport error model, and applies this error model for the purposes of general N-port comparison of calibrations. These tools have been implemented in a commercially available calibration and measurement software product. Previous work demonstrated the utility of these tools in the estimation of calibration error associated with ignoring coupling and for evaluating measurement system repeatability. Equations are presented for bidirectional conversion between an extended 16-term-like error model and the extended 12-term model as well as for calculation of DUT-specific and worst-case multiport calibration comparison error bounds.