Tri-Band Dual-Polarized Shared-Aperture Antenna Arrays With Wide-Angle Scanning and Low Profile for 5G Base Stations

Abstract

This study introduces an innovative tri-band shared-aperture antenna (TSAA) array, designed to align with the demands of current base station antennas in facilitating multi-band integration and enabling independent control. Different antenna types are utilized for each operating band, including 3-D-printed dielectric resonator antennas (DRAs) for the middle bands (MB: 3.4–3.6 GHz) and high bands (HB: 5.4–5.6 GHz), and dipole antennas for the low band (LB: 1.85–2.15 GHz). The TSAA comprises a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\times 4$ </tex-math></inline-formula> dipole antenna array for LB, a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 7$ </tex-math></inline-formula> MB antenna array located at the edges of the aperture, and a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 12$ </tex-math></inline-formula> HB antenna array at the aperture center. The LB antenna array is positioned above the HB and MB antenna arrays, providing wideband electromagnetic (EM) transparency for both HB and MB simultaneously. By exploiting the high dielectric permittivity of the DRAs, the overall array profile is miniaturized to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.13\lambda _{0}$ </tex-math></inline-formula> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda _{0}$ </tex-math></inline-formula> represents the free-space wavelength corresponding to the central frequency of LB). At the same time, the spacing of the antenna unit meets scanning conditions for suppressing grating lobes and achieving wide-angle control of each frequency band. Additionally, adopting symmetric <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\eta $ </tex-math></inline-formula> -shaped stripline coupled feeding technology in the LB antenna effectively improves the problem of tilted radiation patterns typically observed in the HB antenna.