Design of a millimeter-wave phased array antenna for Gaussian beam shaping and steering

A millimeter-wave phased array antenna for Doppler reflectometry within the ASDEX Upgrade tokamak experiment is presented. The antenna radiates a well defined Gaussian beam over almost the whole W-band (75 to 105 GHz). The crucial feed components (phase shifters, coupling structures, focusing elements and single radiating elements), which enable the broadband operation, are presented and discussed. A CAD model of the final waveguide routing of the feed network as well as of the whole antenna with 39 elements is shown.