Application of cubic phase theory to Galindo-Williams subreflector

摘要

A JPL Fortran program for designing the main reflector and the subreflector of a Galindo-Williams system with a constant intensity over the aperture of the main reflector was modified for use on our computer system. Geometrical Optics and conservation of energy are the basic laws used for designing this type of surface. The basic computation is a numerical solution of three simultaneous differential equations. The resulting subreflector is a type of inflected surface. Analysis of the fields scattered from such surface using physical optics yields adequate results. Cubic-phase theory is numerically applied to the Galindo-Williams surface. Although the technique appeared to yield results accurate to within 1015%, the near-ness of the edge to the turning point caused a coupling of the edge and turning point solutions, which prevented higher accuracy.