A source reconstruction method for printed circuit boards with irregularly shaped ground planes

Printed circuit boards’ radiated emissions pose significant challenges for system-level electromagnetic compatibility design. Source reconstruction methods based on near-field scanning can efficiently predict radiated emissions above the printed circuit boards under the assumption of an infinitely large ground plane. However, existing methods are not suitable for printed circuit boards with irregularly shaped ground planes. In this paper, a novel method is proposed to account for irregularly shaped ground planes. Image theory and the surface equivalence principle are employed to compensate sampled near fields above the ground plane. Compensated near fields are then used to construct an equivalent dipole model, with an optimization technique for dipole positions to improve accuracy. Numerical validations are conducted to demonstrate the capability of the proposed method in predicting radiated emissions both above and below the board. A typical shielding problem is analyzed to show its efficiency and accuracy in system-level EMC simulation.