Method of Measuring Common-Mode Current Conversion Coefficient for Estimating Variation in Radiated Emission from Printed Circuit Board Components

This work describes the measurement of the common-mode current conversion coefficient for a microstrip line with solid and slotted ground planes by using a VNA with a BCI probe. The radiated emissions estimated by the common-mode current conversion coefficient are further compared with those obtained by the FAC measurements. Furthermore, the proposed method was used to estimate radiated emissions from a microstrip bandpass filter. For all of the case studies, results of electromagnetic (EM) simulation demonstrate the validity of the measurement results by the proposed method. Highly promising for use in EMI measurement application, the proposed method can estimate the radiated emissions by miniaturized microstrip components on a PCB when pretested for compliance with EMI regulations.