An approach of source equivalance for the fast analysis of high frequency radio wave problems via uniform geometrical theory of diffraction

Uniform geometrical theory of diffraction (UTD) is very efficient in the nu merical analysis of electromagnetic (EM) wave problems associated with geom etry of electrically large objects in comparison with ordinary numerical te chniques such as method of moment (MoM) and finite difference in time domai n (FDTD) because it extracts the most significant field contributions in te rms of a very few ray optical fields. The UTD assumes fields radiated from a point source and suffers from difficulties in situations where the source volume is not extremely small, the object of interaction is very close to the source and only some source information is available. It is noted that discretization over the source for a numerical integration is usually requi red in the prior two situations, which in turn degrades the expected effici ency of UTD. This paper describes a valid approach based on an equivalent r epresentation of a source in terms of relatively few but simple elements th at can be further modeled by an equivalent point source as required in UTD solutions. The source representation is obtained through a best guess from the available source information, and has potential to improve the efficien cy and applicable areas of UTD to the greatest possible extent. Numerical e xamples are presented to validate the proposed approach.