Ultrawideband and Dual-Polarized 1-D Phased-Array Antenna With Reused Structure for Low Profile and High Radiation Efficiency

A dual-polarized 1-D phased-array antenna with a low profile and high radiation efficiency is proposed in this work. Attaining wideband performance with high radiation efficiency is a considerably more arduous undertaking for a dual-polarized 1-D array antenna in comparison to a dual-polarized 2-D array antenna. This is primarily attributed to the significant truncation effect observed in one of the polarizations within the 1-D configuration. To address this issue, a lossless boundary condition reconstruction method based on the structure reuse technique is proposed. The array is composed of horizontal polarization (HP) reused slot antennas (RSAs) and vertical polarization (VP) dipoles. It reuses the HP RSAs as perfect electric conductor (PEC) walls, positioned perpendicularly to the VP dipoles, to mitigate the truncation effect and thereby improve the VP bandwidth. Furthermore, slits are introduced into the RSAs to achieve a 5:1 impedance bandwidth under low-profile constraints, while the dipoles are folded to enhance the impedance-matching performance. Experiment results demonstrate that the antenna achieves 5:1 impedance bandwidth coverage from 0.4 to 2 GHz with active VSWR <3.4 and radiation efficiency over 64% while scanning up to 45° for VP and 60° for HP, respectively. The profile is only $0.11\lambda _{\text {low}}$ at the lowest operating frequency of 0.4 GHz.