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.
Phase Retrieval Algorithm
Mathematical Reconstruction
Computational routines recover the complete complex field information from intensity-only measurements. A phase retrieval algorithm calculates the missing phase of the electromagnetic field by using measured magnitude data collected at multiple planes above a printed circuit board. This algorithm allows engineers to reconstruct the vector near field without the need for expensive phase-resolved measurement equipment.
The algorithm requires sufficient spatial sampling of the field intensity and may fail to converge if the noise in the measured magnitude is high.
Field Projection
Source reconstruction tools use these phase recovery methods to enable accurate far-field radiation predictions from near-field measurements. When a near-field scanner can only record the magnitude of the magnetic or electric field, the phase retrieval algorithm iteratively solves for the phase distribution across the scanning plane. This calculated phase, combined with the measured magnitude, provides the complete vector field required to project the radiation to the far field.
The method avoids the complexity of high-frequency phase-locking hardware, but it requires a high number of measurement points to ensure convergence.
Quality Check
Algorithmic verification compares the reconstructed phase against a known calibration source to confirm accuracy. If the reconstructed and measured fields diverge beyond an acceptable limit, the algorithm’s iteration parameters or measurement spacing must be adjusted. This validation ensures the computed phase is reliable for emission modeling.