Computation of reflector contours for Gaussian beam shaping phased array antenna elements

A numerical procedure for the computation of Gaussian beam shaping reflector contours is presented. The approach applies to one principal plane of the beam. It is based on cylindrical wave expansion of the feed horn radiated field. The designed reflector antennas are supposed to be used as radiating elements in a linear phased array where the principal plane perpendicular to the reflector plane is the steering plane. This phased array will be for use within a Doppler reflectometry system in the ASDEX Upgrade tokamak fusion plasma experiment in Garching, Germany, where a well-defined Gaussian beam is required. One element has been prototyped and measured to verify its properties over the entire W-band (75GHz to 110GHz).