On the number of OTA antenna elements for plane-wave synthesis in a MIMO-OTA test system involving a circular antenna array

To provide background scientific information for the on-going development process of an over-the-air (OTA) test standard for MIMO (multiple input multiple output) terminals, this paper presents a theoretical study on the generation of the plane-wave conditions to the test zone with a finite number of OTA antennas. In particular, such a MIMO-OTA test system is considered, where the OTA antennas lie in the horizontal plane on a circle around the test zone.