Off-axis performance of shaped antennas at millimeter wavelengths


  • Jerome A. Hudson


Antennas which have been shaped for optimal aperture efficiency will not give sharp off-axis images. This is true for even quite small fields of view. The shaping to match feed horn illumination is at fault here; it leads inevitably to severe coma and curvature of the field. The analysis presented here is based upon geometrical optical computations.