A Compact Wideband Monopulse Feed Cluster Implemented via 3-D Metal Printing

This paper presents a compact wideband monopulse feed cluster for antenna tracking applications. The monopulse feed cluster is highly-integrated and developed to provide dual-polarization, wide operational bandwidth and high polarization isolation. The complete feed cluster consists of square-aperture horns for signal transceiving, orthomode transducers (OMTs) for generating dual-polarized signals and magic-tees for constructing a comparator network. All the components are integrated strategically to achieve a compact size. Such a design is extremely difficult to realize via conventional fabrication process, so a 3-D metal printing technique is applied while considering its versatile features in practical fabrication. Preliminary results show that the monopulse feed cluster can operate with polarization isolation higher than 50 dB throughout the operational bandwidth from 10.5 GHz to 14.5 GHz, as well as satisfactory sum- and difference-radiation patterns.