Sure, let’s say you have an s-parameter network that represents a PCB. You have 10 ports, 1 for the DC-DC converter, one for an ASIC and 8 for capacitors. You

Sure, let’s say you have an s-parameter network that represents a PCB. You have 10 ports, 1 for the DC-DC converter, one for an ASIC and 8 for capacitors. You take s-parameter models of the capacitors from the vendor (Murata, AVX, etc) and tie off the ports of the main network to make a 2-parameter network. With a 2-parameter network you can now calculate the equivalence impedance (which is a function of frequency) and plot it or do a spice simulation with ngspice. scikit-rf is one tool that can load touchstone files and perform these kinds of transformations.