The calculation of reflector antenna polarized radiation

A partly analytical process is described for calculating the far-zone patterns of reflector antennas which may have nonlinear polarization. Wave polarization equations are given for a focused but not necessarily symmetrical paraboloid. The process applies for any point-source feed whose radiation characteristics, including wave polarization, are known either by theory or measurements. Calculated and measured patterns are given for a fan-beam antenna whose reflector is
120 \lambda
high and
30 \lambda
wide. They agree well near the axis and agree qualitatively for off-axis angles of several beamwidths. The sources of errors are discussed.