Analysis and measurements of crosstalk in printed circuit board due to RF and transient pulses

This paper describes the EMC problems on the PCB caused by the crosstalk between adjacent traces on the board. Theoretical formulae for near and far end crosstalk (NEXT, FEXT) for three conductor line on printed circuit board for unequal impedances are presented. The line parameters self & mutual inductances and capacitances are evaluated for coupled lines using the even & odd-mode analysis. The NEXT, FEXT magnitudes are computed using MATLAB software and the results are compared with those of experiments as well as Ansoft-HFSS (High Frequency Structure Simulator) package. The effects of RF, switching speed of the input digital signal, transient pulses and different terminal impedances on NEXT/FEXT are analyzed. Optimum design criteria of PCB are discussed for the realistic simulation to achieve EMC.