EMC (Electromagnetic Compatibility)

Any info about EMC on Printed Circuit Board Design and Layout. Concepts and Applications. Thanks... =o)

If we review the PCB board structure, we can see there are two categories:

One is with the surface routed traces, one is with the edge of the PCB board.

For the surface traces, we can think about there is a line current radiator above a ground plane. We can calculate the radiation. This is also the reason why people prefer to route the traces inside the PCB board.

For the edge, we can think this as a parallel plate cavity, at the edge, the EM field will radiate out. You may see people placed a lot of shorting vias around the edge of the PCB board. You may also heard people talking about 20 H rules. Decaps are also used for removing the resonance inside the PCB board.

This brings a very interesting topic, the power delivery system and PCB radiation has a very close relationship.