Role of edge illumination in hemielliptic dielectric lens antenna performance

We study, in accurate manner, the beam collimation ability of a small extended hemielliptic dielectric lens antenna (DLA) fed by an aperture source. This analysis accounts for finite size of the lens and directive nature of the primary feed. Off the internal resonances, which spoil the radiation characteristics of DLAs made of dense materials, the lens edge illumination is found to be of primary importance.