Ray-Tracing Analysis of the Near and Far Fields of Focusing Geodesic Lens Antennas

Geodesic lenses are a class of rotational-symmetric lenses that recently regained interest for the design of multiple beam antennas. Key features of these lenses include mechanical simplicity, wide scanning range and high efficiency. In this paper, a hybrid model to analyze focusing geodesic lens antennas is described. The method combines a ray tracing analysis and a point source array model. This model allows to calculate the near and far fields of a geodesic lens antenna in few seconds. Some results of a lens antenna in the Ka-band are compared with full-wave simulations, validating the model despite small differences in the main beam. This paper also discusses the ability of geodesic lenses to focus the energy in the near field which could be of interest for some applications.