Modeling electromagnetic interference properties of printed circuit boards
by C. R. Paul
The mathematical modeling of a printed circuit board (PCB) for the prediction of its electromagnetic interference (EMI) properties is investigated. Two key aspects examined are crosstalk and the high-frequency voltage developed between the ends of a PCB land (ground drop). The notion of partial inductance as opposed to loop inductance is the key to predicting the high-frequency voltages that are developed between the two ends of a land. Crosstalk predictions are a by-product of the modeling. Experimental results are shown to illustrate the accuracy of the model. A technique for the accurate measurement of the high-frequency voltage developed between two ends of a PCB land is described and explained in terms of partial inductances.