Inverse characterization of antennas by equivalent sources using spherical harmonics

The present paper deals with the analysis of electromagnetic radiations and the interaction of radiated waves with the environment. The characterization by simulation of the phenomena resulting from the interaction of the fields with the surrounding objects requires as a preliminary the synthesis of robust and simple equivalent source models to be integrated in propagation schemes. Methods such as ray-tracing or launched rays coupled with reliable mathematical models such as the Uniform technique of Diffraction UTD then allow a good analysis of the phenomena. The proposed technique is based on the decomposition of a source, of arbitrary geometry and whose dimensions do not allow direct use of the asymptotic methods in its vicinity, into smaller equivalent sources which make possible to calculate the field radiated close to the transmitter. The equivalent elementary sources are represented by their spherical modes. The choice of the number of sources and the number of modes allows us to develop effective models and to account for the objects close to the antennas. To cite this article: A. Gati et al., C. R. Physique 6 (2005).