Troyits'kyj O. Spherical reflector antenna with helical feeders

The mathematical model of multibeam spherical reflector antenna with helical feeders of a different configuration is presented. The variants of the helical feeders executed on different surfaces of rotation (cylinder, hemisfere, sferocylinder) are considered. Formulas for current distribution on the surface of spherical mirror and field of radiation of reflector antenna versus deviation of feeders from a focal axis are shown out.As a result of theoretical research general conformities to the law and features of spherical reflector antenna radiation field forming for different cases of feeders location are set.The constructions of one- and two-arm sferocylinder helix feeders are designed and investigated. These feeders have improved axial ratio (appr. 1.08) and active input impedance (50 Ohm) in 40% frequency band.