Reducing simultaneous switching noise and EMI on ground/power planes by dissipative edge termination

Power and ground planes should exhibit low impedance over a wide range of frequencies. Parallel ground and power planes in multilayer printed-circuit boards exhibit multiple resonances which increase the impedance and also the radiation from the board edge. Resistive termination along the board edges reduces the resonance peaks. Simple and straightforward design expressions, simulated self and transfer impedances, and measured impedance and radiation plots are presented for a pair of 10" by 10" planes with 31 mil FR4 dielectrics.