Effect of the off-focus shift of the feed on the radiation characteristics of a 2-D parabolic reflector antenna

The parabolic reflector antennas are widely used in the telecommunication systems and generally have large aperture sizes like 50λ to 80λ and larger. Their reliable full-wave analysis with the conventional Method of Moments (MoM) or with the other numerical methods is difficult because of inaccessible speed and accuracy. This statement is valid both for 3D and 2D reflector antennas in both polarizations. The Method of Analytical Regularization (MAR) constitutes an alternative solution compared to the ordinary MoM, which can provide only 1-2 digit accuracy. It provides finer accuracy within a reasonable computation time because the computational error can be decreased simply by increasing the matrix size in MAR. We have previously developed this method for the accurate simulation of the arbitrary conical section profile 2D reflector antennas, and the corresponding codes have provided us with accurate benchmark data. Here we study a similar problem however with the feed simulated by Complex Source Point (CSP) source located at an off-focus point on the symmetry axis of a front-fed reflector antenna. The numerical results are presented for the radiation characteristics including the forward and backward directivities and the radiation patterns in all directions. © 2010 IEEE.