Asymptotic analysis of parabolic reflector antennas

It is shown that complex ray theory provides an analytically tractable numerically accurate procedure for tracking beam-type incident fields from the source to a reflecting surface and then to the near or far zone without the need for intervening integrations over an equivalent aperture plane. For paraxial fields described by slightly complex rays, all relevant information can be obtained by perturbation about real solutions descriptive of the behavior on the central ray. This feature suggests extension of the method to multireflector systems by utilization of results developed for real ray fields in such systems, even when reflecting surfaces are specified numerically.