Fields in the focal region of paraboloid and offset paraboloid reflectors

While much development has been accomplished for reflector antenna technology, a need still exists in evaluating the impacts of design parameters. One such area lists with the design tradeoffs associated with the beam-scanning performance of reflector designs. A surface current integration analysis is derived which is exact to the order of physical optics. This analysis is applied to both circular and offset reflectors for on-axis and off-axis illumination for parameters which span the cases for which both substantial and minimal degradation with beam scan occur. The output of the analysis is cast in the form of contour plots defining the field structure in the focal region of the reflector. The results of the analyses compare favorably with data previously obtained for specialized parameters. Keywords include: Physical Optics Currents, Numerical Integration, Cassegrain Antenna, Offset Paraboloid Antenna, Contour Plots for Fields, and Angle of Scan.