Waveguide to Coaxial Transition in Disk-on-Rod Feed Array Element

In this paper, a multiple feed per beam antenna based on disk-on-rod cluster feed array is presented. The cluster has one active and six peripheral elements. Peripheral elements do not have inputs and their excitation is provided by mutual coupling in the cluster. Active element has waveguide to coaxial transition which provides good matching and aperture efficiency. Optimization of this transition is considered and results are reported.