Multibeam single aperture diverging lens antenna

A single-lens multibeam antenna has been developed with a planar focal surface which does not have the critical alignment problems inherent with multilens systems. By way of demonstration, the authors have built and tested a breadboard model lens to provide 37 contiguous beams to cover the earth´s field of view. The lens was designed to give high efficiency, low sidelobe, circular beams at 44.5 GHz. Test results show that the required performance can indeed be achieved using a single nonfocusing lens with a planar focal surface. A vector diffraction computer program has been developed for the lens to compute the secondary radiation patterns. It calculates the physical optics currents over the spherical surface based on the geometrical optics and far-field patterns using the vector diffraction integral.<>