Design of a Compact Wideband Feed Cluster with Dual-Polarized Sum- and Difference-Patterns Implemented via 3-D Metal Printing

A compact wideband feed cluster with dual-polarized sum- and difference-patterns is proposed in this paper. By utilizing dual-ridged waveguide orthomode transducers (OMTs) and wideband Magic-Tees, a highly integrated feed cluster with wide operational bandwidth, dual-polarization, and good isolation is developed. The feed cluster consists of five horns with square apertures arranged in a cross. A total of five OMTs and four Magic-Tees are used to construct the necessary comparator network to achieve sum- and difference-patterns in both polarizations. All components and the interface between them are designed with the three-dimensional metal printing in mind. A prototype is fabricated and the measured results show that the isolation between the orthogonal polarizations is better than 50 dB throughout the operational bandwidth of 10.5 to 14.5 GHz. The null-depths of the difference-patterns are better than -30 dB. The proposed feed cluster is practically useful in a variety of satellite-based applications.