Dual-Polarized, Low-Profile Dipole-Patch Array for Wide Bandwidth Applications

This article proposes a low-profile, dual-polarized
$4\times 4$
antenna array for the fifth-generation (5G) applications. It originates from our previous linear-polarized design, but with two split dipoles. For each polarization, the current on the split dipoles will cancel each other out in one direction. In contrast, in the orthogonal direction, the current can be regarded as a driven dipole to couple energy to four parasitic patches. The proposed element has a profile of only
$0.073\lambda _{0}$
(where
$_{\mathrm {}}\lambda _{0}$
is one free-space wavelength at 27.85 GHz) with simulated standing wave ratio (SWR) < 2 from 22.11 to 33.6 GHz (BW ≈ 41.25%). The average gain is 8 dBi, and the peak gain reaches 10 dBi at approximately 31.5 GHz. Besides, the two polarizations possess almost the same performance due to the symmetry of the antenna. A 4
$\times 4$
antenna array is designed, simulated, and experimentally demonstrated based on a subarray that can support two orthogonally mode excitations. The measured results present an overlapped bandwidth of 28.4% and more than 25 dB isolation. In addition, the maximum gains are up to 19 and 18.9 dBi for Ports 1 and 2 excitations, respectively. Our proposed design has great application potential in vehicle-mounted millimeter-wave radar and 5G communications systems.