Reconstruction of Current Distribution on a Given Conductor Structure Using Frequency Domain Near-Field Data without Phase Information

Information on field emissions is required in many applications. Typically, antennas are used for the measurement of the far-field. Antenna measurements suffer from several problems, e.g. the need of large anechoic chambers. Near-field measurements/scans might become an attractive alternative in the future. The far-field can finally be calculated from near-field measurement data. For an accurate calculation, phase and amplitude distributions of the near-fields are needed for all considered frequencies. As phase measurement can be very troublesome, the reconstruction of the phase from phase-less measurement data is highly attractive. In this paper, a method is presented to find the EMI of PCB traces or similar structures with phase-less near-field measurements. In this method, knowledge of the geometry of potential radiating is applied. From this knowledge, boundary conditions can be found for phase estimation. The method is shown in detail and the benefits are discussed on result of reconstructed current distributions and estimations of the far-field.