S-parameters for High-frequency Circuit Simulations

Scattering parameters (S-parameters) are frequency-domain reflection-transmission measurements, or models,that are used to simulate inductors, wide-band transformers, and common mode chokes at RF and microwave frequencies. S-parameters can accelerate the simulation process by placing a single “black box” element into a schematic and pointing to a file. This avoids having to create complicated lumped-element (SPICE) model schematics that only approximate distributed characteristics.While easier to set up in simulation, users should understand the challenges and limitations of using S-parameters before analyzing simulation results. In this note, Coilcraft discusses the basics of S-parameters and when they are appropriate for circuit simulation.