Electromagnetic source modeling using phase retrieval methods

Modeling of the field distributions from electromagnetic sources is of interest for various applications for example electromagnetic compatibility investigations, near-field to far-field transformations, antenna diagnostics and electromagnetic dosimetry. In order to determine whether exposure safety guidelines, such as the EU directive 2004/40/EC, are complied with, source modeling methods are important. Two methods for determining the total field, including phase information, when only field amplitudes have been measured on a set of planes in front of an electromagnetic source have been developed. The first method, the adjoint field method, is a gradient based optimization algorithm based on the adjoint fields. The second method, the phase angle gradient method, employs an optimization algorithm based on the phase angle gradients of a functional. Promising results have been obtained both for numerical test cases and for measured field.