A Hybrid Schatten p-Norm and Lp-Norm With Plane Wave Expansion Method for Near–Near Field Transformation

Near field scanning is one of the most useful methods for electromagnetic interference (EMI) diagnosis. However, large scanning points and long scanning time are the major obstacles when the device under test is complex. To resolve the issue, a novel hybrid method including two steps to quickly predict the near field pattern of an unknown EMI source is proposed. The first step is to reconstruct a full field pattern from a sparse scanning using the joint Schatten
p
-norm and
Lp
-norm method, where less sampling points are required on the original scanning plane. The second step is the near–near field transformation based on the plane wave spectrum method. It uses one single field pattern to derive the field distributions on multiplanes around the EMI source by introducing a calibration factor. The source reconstruction method in the second step can also be used to predict far field and coupled power to the victim circuit. Both simulation and experimental examples have validated the feasibility of the proposed method.