Single-Layer Wideband Tilted Beam Phased Array Antenna for Millimeter-Wave Vehicle Communications
Kai Chen, Jun Xu, Qingqing Lin, Yuanwei Zhu, Wei Hong
Abstract
In this article, a wideband tilted beam phased array antenna is proposed for millimeter-wave (mmWave) vehicle communications. The developed antenna element obtains a measured | <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> |<−10 dB impedance bandwidth of 49.4% (23.3–38.6 GHz) by loading two monopoles ahead of the open-end aperture of a single-layer substrate integrated waveguide (SIW) with an etched transverse slot, thus, covering multiple allocated mmWave bands of the fifth-generation (5G). Meanwhile, the loaded two monopole structures also introduce a broadside radiation aperture, which combines with the original end-fire radiation aperture forming a stable 45° tilted beam pattern within the frequency band. Prototype of a 1 × 4 phased array is fabricated and measured, and the beam scanning performance of the array is verified using a multi-channel beamformer, with a 3 dB beam scanning range exceeds 86° at 27 GHz. The proposed antenna boasts the characteristics of wideband, a stable tilted beam, and good beam scanning performance, rendering it a promising candidate for mmWave vehicular communications. Additionally, a hybrid 2D beam scanning is realized by combining a cylindrical Luneburg lens antenna with the 1 × 4 phased array to fully exploit the advantages of both techniques. Experimental validation has also been carried out to confirm the feasibility of the proposed hybrid 2D beam scanning scheme.