Common mode radiation of a printed circuit board with embedded decoupling capacitor excited by IC's shoot-through current

Electromagnetic radiations of power bus with embedded decoupling capacitor composed of different insulator thicknesses were investigated for two cases: with on-board global capacitors and without them. In order to distinguish the common mode radiation of the power bus due to shoot-through current from normal mode radiation, two different lengths of signal traces were compared. It has been proved that radiated emission due to shoot-through current was reduced over the wide frequency range by the PCBs with thinner insulators without on-board global capacitors, and was reduced in the limited frequency range by the PCB with relatively thick insulator and on-board global capacitors.