Suppression effect of the emission from a printed circuit board using a ferrite plate

摘要

Radiated emission from a printed circuit board (PCB) is a serious topic in a field of EMC/EMI. In order to suppress the radiated emission, it is used some type of electromagnetic absorber, such as ferrite plates or carbon plates. To investigate the appropriate use of a ferrite plate, we analyze the suppression effect of a ferrite plate that is placed nearby a PCP with a microstrip line. Frequency dependent finite different time domain (FD-FDTD) method is used as an method The calculated results show that the suppression effect is achieved by the ferrite plate placed at a large magnetic held intensity. In the case of a PCB with a finite ground plane, the suppression effect is achieved by the ferrite plate placed on the ground plane opposite side of a microstrip line.