A Heuristic Method for Determining Far-Field Distance of mmW 5G Massive MIMO Antennas

Small patch antennas arranged in a matrix form are used in millimeter wave wireless devices. These types of antennas are not detachable from the devices. Compliance and other characterizing tests must be performed over the air. Measurements in the near-field are potentially problematic because the test data cannot be accurately extrapolated to different distances. Therefore, most measurements must be made in the far-field. For determining the far-field distance, the device and measurement antenna, both apertures must be considered. While the far-field distance of conventional antennas can be approximately predicted using traditional methods, presently, there is no known method for determining the smallest far-field formation distance of massive MIMO antenna system. This paper describes a heuristic approach for determining the far-field formation distance of millimeter wave massive MIMO antenna systems used in 5G transceivers.