GTD Analysis of a Strip Scatterer in the Near Field of an Antenna

摘要

Various computer codes have been developed by using Geometrical Theory of Diffraction (GTD) to calculate the scattering effects associated with antennas in the presence of scattering structures. These codes are most useful for low gain antennas although they can simulate large antennas using the superposition principle. Unfortunately, this approach results in large computer run times for antennas that have to be subdivided into many smaller elements. Two approaches for overcoming this limitation in two-dimensional cases are investigated in this thesis: a) the large subaperture technique and b) the two-point GTD source field method. Both approaches use the GTD method to calculate the scattering from structures in a similar way to that used in the present codes. However, the fields of the antennas or sources are treated in ways to permit more efficient calculations in these approaches. Both approaches have turned out to be useful and complement each other. (Author)