How to do Accurate OTA (over-the-air) Production Test in Seconds?

How to make accurate radiated power and pattern measurements in seconds in production testing of wireless devices or antennas?

Model: TESTxpert

AUT: The device tested in the video is the MIMO tool which has 4 printed patch antennas on the back side. These patches are linearly polarized E-shaped with a PIFA type structure. They are organized in a rectangular grid.