3D-Printed All-Metal Modular Low-Profile Ultrawideband Tightly Coupled Dipole Arrays

All-metal array antennas have always been preferred due to their features, such as higher power capacity, higher structural strength, and lower passive intermodulation (PIM). A novel all-metal modular tightly coupled dipole array (TCDA) is proposed and realized for the first time in this article. The proposed TCDA has uniquely shaped planar dipole arms, effectively minimizing the antenna profile. Meanwhile, the novel element facilitates the modular assembly of arrays with arbitrary sizes and shapes, enhancing the ease of replacement in case of damage to some elements. The array edge truncation effect can, moreover, be alleviated by just using half-sized elements (HSEs), thereby effectively reducing the aperture sizes of traditional TCDAs with dummy elements. Simulation results show that the proposed TCDA is able to operate at 4.67:1 bandwidth (0.45–2.1 GHz) for broadside, and is able to scan up to 60° in the E-D-plane and 45° in the H-plane within 0.5–2 GHz, with a rather low profile of only $0.48\lambda _{\mathrm {H}}$ at the highest operating frequency. The proposed all-metal TCDA of a $3\times 9$ modular rectangular array, a ring-shaped array, and a cross-shaped array were realized by 3-D printing technique without any welding. Good agreement is achieved between the simulated and measured results.