A Wideband Frequency Beam-Scanning Antenna Array for Millimeter-Wave Industrial Applications

<p>In this article, a compact, wideband, and high-gain frequency beam-scanning planar microstrip series-fed antenna array based on  PCB technology is presented at 60 GHz ISM band with enhanced performance.  First, a wideband 8-element linear antenna array is designed that provides -10 dB impedance bandwidth of 41.52% (54–82.3 GHz) covering the entire 60 GHz millimeter-wave (mmWave) ISM band from 57–71 GHz. The linear array produces fan-beam patterns, and has a peak realized gain of 13.48 dBi at 64 GHz, with less than 1 dB gain variation within the entire 57–71 GHz. Then, the proposed linear array is employed as a sub-array in a hybrid parallel-series topology to design a compact and high-gain 64-element (8 × 8) planar array. The planar array covers entire 57–71 GHz band with the peak measured gain of 20.12 dBi at 64 GHz and less than 1 dB gain variation within 57–71 GHz, thereby providing 1 dB gain bandwidth of 14 GHz. The planar array provides narrow directional beams with an average half-power beamwidth of 9.7° and 11.78° in the elevation and azimuth planes respectively, for point-to-point multi-gigabit mmWave connectivity. The phase variation of the series-fed topology is employed to produce frequency beam-scanning range 40° in 57–71 GHz band, which is experimentally elucidated. The array prototypes are fabricated and measured. The measured and simulated results show reasonably good agreement, thus validating the performance of the proposed antenna array for 60 GHz mmWave ISM band applications.  The proposed wideband antenna array is a suitable candidate for numerous emerging mmWave industrial wireless applications in context of Industry 4.0 and Industry 5.0, as well as 60 GHz FMCW radars. The array is compatible to work with various 60 GHz physical layer protocols such as IEEE 802.11ay, IEEE 802.11ad, IEEE 802.15.3c, WirelessHD, and ECMA-387 as well as other customized industrial protocols such as WirelessHP. </p>