© Author(s) 2012. CC Attribution 3.0 License. Advances in Radio Science

Abstract. A restriction in using electromagnetic ray tracing for field prediction is given by the far-field condition: the re-sults are only valid in the far-field region of the radiator. In this paper, it will be shown how ray tracing for accurate field computation can also be applied in the near-field regions of transmitters. The reduction of required large distances be-tween transmitter and receiver is achieved by subdividing the transmitter in smaller subtransmitters. Even for com-plex transmitters, e.g. antennas with objects in close prox-imity such as metallic carrier platforms, subtransmitter mod-els can be very efficiently generated by using the Multilevel Fast Multipole Method (MLFMM). This well-known inte-gral equation solving technique makes very large problems in computational electromagnetics manageable. The subtrans-mitters can be directly generated based on this algorithm. A simulation example will show the improved modeling accu-racy and options for simplification and refinement will also be discussed.