Reduction of electromagnetic interference caused by an image plane for a PCB

This work examines the electromagnetic interferences (EMI) on U-shape I/O ports resulted from the noises of an image plane, and provides an useful approach to potential reduce them. These U-shape I/O ports popularly exist on the PCBs of information technology equipments, where the image planes are generally referred to the conducting layers in the vicinity of electric circuits and signal sources such as a power plane, a ground plane and a chassis plane. Both numerical simulations and measurements are employed in the examinations, and exhibit useful characteristics in reducing the EMI influences.