Application of UTD and spherical wave theory to reflector antenna analysis

There is a growing need, especially in space based systems, to make quasi-optically fed antenna systems as compact as possible. Gaussian beam mode analysis cannot fully electromagnetically evaluate such systems. A modular analysis scheme with a common electromagnetic interface between each individual quasi-optical component analysis, enabling the most suitable analysis method for each component to be employed is proposed. This paper describes the current state of such a study, where we first consider the spherical wave expansion as that interface. An arbitrarily shaped single reflector is analysed by combining spherical wave theory with the uniform theory of diffraction (UTD) to produce a reflector analysis module. Results using this system are described.