Dual reflector polarization transformers

A few different kinds of first-order partial differential equation (PDE) are presented to shape the subreflector surface in a dual-reflector antenna, transforming the given polarization distribution of the incident toroidal wave to that given over the plane wave. The main reflector is calculated as soon as the subreflector is known. Varying the tore radius from zero to infinity, the subreflector surface PDE can be obtained for many important cases, namely for spherical, cylindrical, or plane incident waves. The beginning value for the PDE-arbitrary subreflector curve is still free and may be chosen to minimize any prescribed object function. The results are derived under the geometrical-optics approximation.<>