Widebeam Coverage Antenna Solution for Low-Complexity mmWave Indoor IoT Network

This article proposes a widebeam coverage antenna solution for a low-complexity millimeter-wave (mmWave) indoor Internet of Things (IoT) network. The proposed switched beamforming antenna (SBA) system eliminates the need for complex feed networks or beamformers by utilizing a single RF switch and multiple radiators. Each radiating element of the antenna is capable of generating multiple main lobe directions, ensuring wide beam coverage and sufficient antenna gain. This design approach effectively addresses the key requirements of distributed antenna system (DAS) configurations, including low complexity, low loss, low power consumption, and cost effectiveness for indoor IoT networks. To validate the effectiveness of the proposed SBA solution, a three-radiator-based SBA was fabricated. The antenna core size was compact, measuring
$1.77\,\,\lambda _{0} \times 4.3\,\,\lambda _{0} \times 0.05\,\,\lambda _{0}\,\,(\lambda _{0}$
representing the free-space wavelength at 28 GHz). This compact size is more suitable for indoor low-profile networks compared to previously reported SBAs. Experimental measurements revealed peak gains of 5.62, 7.2, and 5.77 dBi for the three different radiation patterns, respectively. Moreover, each beam pattern exhibited a measured 3-dB beam coverage of 101°, 64°, and 106°. The overall 3-dB beamwidth of the system based on the peak gain of the boresight ranged from −66° to 64°, which is wider than previously reported works.