Frequency-domain interpolation of long structures for system-level Signal Integrity analysis

System-level modeling requires cascading frequency domain characteristics of the subparts of the system. It can only be done if the data is given in the same frequency samples. Since often it is not the case, interpolation has to be done to reduce the data to the same frequency points. Incorrect interpolation might create nonsense artifacts, especially if the model includes a long structure. In the present work interpolation problems of a frequency response data are studied. The practical solution for these problems is suggested and different measured test cases are investigated.