Evaluation of a Random Line-of-Sight Over-the-Air Measurement Setup at 28 GHz

Over-the-air (OTA) measurement techniques have, and will continue to have, a key role in evaluating the performance of modern antennas and wireless devices. The new random line-of-sight (random-LOS) measurement setup offers the evaluation of the OTA performance of different types of devices, for example, car antennas and small wireless devices in the random-LOS environment. A plane wave is synthesized in the test zone of the OTA setup, where the far-field of a radio base station can be emulated. We present measurements and simulations of the random-LOS OTA measurement setup, employing a reflector antenna, with a dual-polarized linear array feed, operating at the 28 GHz band. An analysis of the power and phase-field distributions in a cylinder and a circular test zone is presented. The computed standard deviation (STD) of the power distribution is approximately 1dB within a circular test zone, with a diameter of 0.3m. The STD of the phase, within the same test zone, is less than 15°. The radiation patterns of a horn antenna have been measured in the random-LOS measurement setup and shown a good agreement with the theoretical values.