The 20-H rule is a printed circuit board layout guideline. On boards with power and ground planes, the fringing field at the edges of the board is contained by backing the edge of the power plane away from the edge of the board by a distance equal to 20 times the separation distance between the planes. In this study, test boards were built and measured with and without implementing the 20-H rule. The measured results are compared to numerical models. The results of this study show that, although the near fields are more contained, the radiation from a board implementing the 20-H rule is actually slightly higher than the radiation from boards with a traditional design

Meeting Name

IEEE International Symposium on Electromagnetic Compatibility, 2001


Electrical and Computer Engineering

Keywords and Phrases

20-H Rule; EM Radiation; EMC; EMI; Electromagnetic Compatibility; Electromagnetic Interference; Fringing Field; Ground Planes; Numerical Models; Planes Separation Distance; Power Planes; Printed Circuit Board Layout Guideline; Printed Circuit Layout; Printed Circuit Testing; Test Boards

Document Type

Article - Conference proceedings

Document Version

Final Version

File Type





© 2001 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jan 2001