Effects of 20-H rule and shielding vias on electromagnetic radiation from printed circuit boards

As the operating frequency of electronic circuits continues to increase, package and printed circuit board designers face more radiation problems than ever before. The control of radiated emissions to make the package comply with radiation constraints is one of the most important aspects of the EMC study. Some "rules-of-thumb" are employed to help the designers to reduce the radiation problems. This paper presents an investigation on the effects of the 20-H rule (Montrose, Printed Circuit Board Design Techniques for EMC Compliance, IEEE Inc., 1996; Pantic-Tanner and Gisin, IEEE EMC Soc. presentation, 2000) and the shielding vias on electromagnetic radiation from printed circuit boards.