A method to overcome the limitations of G.O. in axis-symmetric dielectric lens shaping

The design of a cylindrically symmetric dielectric lens antenna is presented for the case of a very squeezed fan-beam. One makes use of geometrical optics (G.O.) to establish the profile of the lens in a first step. A half-integrated solution of Green's formula for bodies with cylindrical symmetry and circularly polarized surface fields is then derived to calculate the radiation pattern. Since the use of G.O. is restricted to some conditions which were observed unsatisfied in our study, a two-steps procedure to reach an acceptable lens shape is then presented. The first step is based on weighting the source beam of the antenna; and the second one is based on simple geometrical interpolation. Prototypes provided experimental results that are consistent with the predicted radiation characteristics and interesting features of such antennas are pointed out