Investigation of the characteristics of low-cost and lightweight horn array antennas with novel monolithic waveguide feeding networks

3D printed X-Ku band single horn antenna and 2 × 1 and 2 × 2 pyramidal horn array antennas with novel lightweight and monolithic waveguide feeding networks (WFNs) are proposed at 10-15 GHz for satellite communications and radar systems to increase the gain. Proposed novel fabrication method consists of two main steps that are to make the skeleton of horn array antenna from acrylonitrile butadiene styrene (ABS) thermoplastic via 3D printer and to perform copper plating over all surface of antenna by using the electroless plating and electroplating processes. The WFN structures with 3λ element spacing designed and realized by using WR75 waveguide T-junction, E-type bend, and UDR 120 flange. Qualitative agreement between measurement and simulation via CST Microwave Studio is obtained with max 1 dB due to high precision and surface roughness. The gains of array antennas are increased by about 1.5 dB and 3 dB, respectively compared to the single antenna. VSWRs of array antennas are 0.3 dB and 0.6 dB, respectively higher than the single one. In the study, proposed 3D printed components not only with 90% lighter weight than, but also with 80% cheaper than commercial products, and horn arrays with -40 dB cross-polarization values.