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.
Planar Dipole Reconstruction
Source Localization
Mathematical modeling techniques determine the equivalent currents on a printed circuit board by analyzing the measured external magnetic and electric fields. Planar dipole reconstruction calculates the equivalent magnetic and electric dipole distributions on a flat plane corresponding to the board layout. This reconstruction provides a map of the virtual noise sources that represents the true emission behavior of the circuit.
The reconstructed dipole model is valid for field calculations anywhere outside the immediate volume of the board.
Emission Diagnosis
Diagnostics of electromagnetic interference on complex multi-layer boards use this reconstructed dipole map to locate current loops and trace radiation points. When the physical board traces are buried in internal layers, planar dipole reconstruction allows engineers to find the coordinates of the noise sources without stripping the board. This calculated map of dipoles is compared with the CAD layout to identify the specific signals or vias causing the emission.
The resolution of this reconstruction depends on the distance between the scanning sensor and the board surface during data collection.
Model Evaluation
Validation of the dipole model is performed by comparing the calculated far-field emissions with actual chamber measurements. If the simulated far-field radiation matches the chamber test data, the reconstructed dipole distribution is deemed accurate. This confirmation allows engineers to rely on the virtual model for evaluating design revisions.