Extraction of Parasitic Parameters Using Scattering Parameters
Parasitic parameters are very important in EMI filter's high frequency performance. In order to investigate them, overcome them or utilize them, they must be first identified and quantified. A network parameter, scattering parameters (S-parameters) is proposed to extract the parasitics in EMI filters. The advantages of S-parameters include that they can be calibrated to the exact measurement interface and they are easy to be measured accurately at high frequencies. The extractions are carried out for every component pair in the filter. The measured S-parameters is then fed to Matlab for parasitic extraction. The extracted parasitics are fed to the circuit model in Pspice for simulation. The simulated insertion gains can perfectly match the measured insertion gains. By changing certain parasitics in the simulation together with some experiments, the effects of parasitics on EMI filter performance can be studied.