Effect of extra CX on EMI filter performances

With the accurate extracted noise source and noise termination impedances, an electromagnetic interference (EMI) filter can be designed systematically with optimal results, that has been already proved in the literature. In this paper, the extension example to verify the sensitivity and the robustness of the EMI filter design procedure based on the two-probe measurement technique by adding an extra C_X is demonstrated. From the experimental result, it confirms that the proposed EMI filter design procedure is not only avoid the tendency of over-designing EMI filter components, but there are insensitivity and robustness inherent in the proposed procedure also.