Phase Resolved near Field Dipole Reconstruction for Multilayer Board Far Field Escape Prediction
Phase-resolved near-field dipole reconstruction predicts far-field escape emissions within 2 dB, eliminating un-phased scan errors before SAC testing.
Equivalent Source Modeling
Source Representation
Numerical approximations substitute complex physical current distributions with a simplified set of localized emitters. Equivalent source modeling replaces the actual, intricate trace geometry of a printed circuit board with an array of elementary dipoles that recreate the same external electromagnetic fields. This modeling approach enables rapid estimation of radiated emissions without requiring a full three-dimensional discretization of the internal board structure.
The modeling remains valid only in the region outside the boundary enclosing all equivalent sources.
Scan Simulation
Radiation scanning of electronic assemblies uses these arrays of simplified emitters to model electromagnetic interference in the near and far fields. When a scanner measures the magnetic field above an operating circuit board, equivalent source modeling back-calculates the strengths of the virtual dipoles that would produce the observed field. These calculated sources are then used to predict fields at other distances or under different shielding configurations.
The technique avoids the need to model every active trace and component package, but its accuracy depends on the density and placement of the measurement points.
Model Verification
Validation of the source model checks whether the reconstructed fields match independent measurement data. If the deviation between the modeled and measured field exceeds a pre-set threshold, the source distribution is refined through iteration. This step ensures the reliability of electromagnetic compatibility predictions.