Extraction of the Parasitic Model for Integrated EMI Filters
Integrated EMI filter has a planar structure. All DM, CM capacitors and DM, CM inductors are integrated and fit into a planar core. Since all components are very close to each other, the structural parameters between components could be very important to EMI filter's performance. To efficiently reduce or cancel these parameters so as to improve filter's performance, they must be first identified and extracted. Structural parameters exist in the integrated EMI filters, so they cannot be measured separately. A method is proposed in CPES to extract these structural parameters. In the first step, the equivalent circuit of the structural parameters based on the physical structure of the filter is built. In the next step, the impedance measurements from terminals are carried out. By leaving other terminals short or open, many groups of independent impedances can be measured. Finally, the measured impedances were calculated and mapped to the equivalent circuit. The simulated model can match the measurement very well.