EMI from printed board
The biggest source of radiated energy are improperly routed and/or terminated traces. Every trace on a PCB, regardless of length, is a transmission line. A properly routed trace has the smallest signal loop size, providing the least amount of opportunity for signal radiation and/or coupling. A properly terminated trace dissipates its energy in the load, leaving little or no energy to be radiated to adjacent structures.
Beyond the circuit board itself, any circuit structure or component having high current and significant signal loop size can act as a source of EMI. Electromagnetic devices such as fans, relay coils, solenoid coils, speaker coils, etc., are strong field emitters, and can couple noise into adjacent circuits.
Sorry, is it enough to simulate EMI only from conductors on a printed circuit board to estimate total EMI from board?
the biggest source of EMI in PCBs are return paths of signals.We always take care of the forward signal path.We never takes care of the return paths of the signals.
This causes most of the EMI(90%) in the PCB.