EFFECT OF DIELECTRIC COATINGS ON PARABOLIC REFLECTOR ANTENNA PERFORMANCE

The effect of a dielectric coating on the gain, co-polar radiation pat tern, and cross-polarization level of a linearly polarized parabolic r eflector antenna is investigated for both dry and wet surface conditio ns using a physical optics analysis of the equivalent surface currents . By choosing the correct thickness, the effect of a dielectric coatin g can be minimized, and, at the same time, an equivalent metal-reflect or representation shows that the antenna gain is less sensitive to the coating surface accuracy. (C) 1995 John Wiley & Sons, Inc.