Plane wave compensation technique for multiple‐input multiple‐output over‐the‐air testing in small multi‐probe anechoic chamber

Abstract

Multiple-input multiple-output (MIMO) over-the-air (OTA) testing is often executed in multi-probe anechoic chamber (MPAC), the size of which is generally large enough so that the waves radiated from the probes can be considered plane waves in test area. The physical dimension of test setups is a key cost factor. In order to save laboratory space and reduce the cost, a compensation technique for spherical waves synthesising plane waves is proposed, which can be applied in small anechoic chamber. The object is to investigate the performances of the proposed plane wave compensation technique on MIMO terminal OTA testing in small MPAC. In the simulation, this technique presents good performances on various metrics, e.g. field distribution, spatial correlation, power angular spectrum estimation. As demonstrated in simulation, the ring radius of anechoic chamber can be reduced and the conventional far field criteria can be relieved.