The reduction method for radiation noise from power supply layers in PCB

This paper describes the reduction method of radiation noise from power supply layers in Printed Circuit Board (PCB). High speed switching operation of Large Scale Integration (LSI) causes power supply noise, and it causes radiation noise. Proposal method is attached resistor between power supply layers of substrate edge, and radiation noise is reduced. Attached resistor prevents reflection of noise wave and absorbs noise energy. In order to reduce the DC power of power supply layers, capacitor is connected to resistor in series. In frequency 0-10 GHz, we examined the optimal attached resistance value. Power supply layer is considered to be aggregate of lines, and the characteristic impedance of the line was calculated. As a result, when attached resistance value made equal to the characteristic impedance of 1 cm width signal line, the most outstanding reduction effect was acquired.