De-embedding of filters in multiplexers via rational approximation and interpolation
In this article, we present a method to recover electrical parameters of filters embedded in a multiplexer for which scattering measurements are given. Unlike other approaches proposed for this problem, this method does not require a priori knowledge of the scattering parameters of the junction. This feature renders the procedure well suited for tuning purposes or for fault diagnosis. Technically, the algorithm starts with a rational approximation step, to derive a rational representation of certain scattering parameters of the multiplexer. This representation is then used in a second step to identify an electrical model of each filter. This second step relies on a rational interpolation technique used to extract the filter's responses.  2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:647654, 2015.
de-embedding rational approximation fault diagnosis diplexer filter tuning pad interpolation