Low-Profile, Broadband, Dual-Linearly Polarized, and Wide-Angle Millimeter-Wave Antenna Arrays for <i>Ka</i>-Band 5G Applications
Xuanfeng Tong, Zhi Hao Jiang, Chao Yu, Fan Wu, Xin Xu, Wei Hong
Abstract
A low-profile, broadband, dual-linearly polarized (dual-LP), and wide-angle millimeter-wave antenna array with beam-steerable capabilities operating in the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ka</i> -band is proposed for 5G applications. By jointly exploiting miniaturized vertically stacked elliptical patches, orthogonal aperture-coupled stripline feeding structures, and groups of shorting pins loaded close to the coupling apertures, the proposed dual-LP element has a small footprint of 4.5 × 4.5 mm with a total thickness of 1.57 mm, which exhibits a measured −10 dB impedance bandwidth of 21.8% and a mutual coupling below −41 dB. Wideband stripline-based Butler matrix circuits are designed and integrated with the 1 × 4 element array for verifying its broadband dual-LP multibeam radiation performance. Experimentally, the integrated array generates four beams with an angular coverage of about ±61° and ±75° for <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> - and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i> -polarizations, revealing that the proposed array is a promising candidate for 5G applications.