Path Loss and Directional Gain Measurements at 28 GHz for Factory Automation

Achieving adequate coverage with high gain antennas is key to realizing the full promise of mm/cm bands to support factory automation. We report an extensive measurement campaign at 28 GHz inside a factory environment, with over 400 LOS and NLOS links measured for ranges of 5-90 m, using a specialized narrowband channel sounder. The measurements were done with a 55° (10 dBi) transmit antenna at 1 m height, emulating a terminal, and a 10° (24 dBi) receive horn antenna at 2.5 m height, emulating a near-ceiling base station. The 10° base horn antenna was spun at speeds up to 300 rpm to capture azimuthal angular power distribution. Measured path gain-distance dependence is well represented by power-law models with a slope of 4.1, with log-normal deviation of 4.3 dB. Azimuth gains at the base are degraded by scattering by up to 7 dB for 90% of links.