Hybrid FDTD-SPICE analysis of radiated emission from PCB with integrated circuits

The radiated emission from ground bouncing and transmission lines have been analyzed using the finite difference time domain (FDTD) and SPICE hybrid method. This method can consider both the nonlinear electric characteristics of IC and the distributed parameters of printed circuit boards (PCB). The computed results of the electric field at 3 m from the PCB were validated by the measurements. The hybrid tool allows calculation of the noise spectrum and radiation pattern. Another advantage is that this method can separate the contributions of various noise sources. This analysis tool and methodology is useful to design transmission lines and power/ground planes in PCB.