Asynchronous 256-Element Phased-Array Calibration for 5G Base Station

This letter presents the phased-array antenna calibration of the 5G millimeter-wave base station (BS). BS and the instrument are not synchronized with the common 10-MHz reference considering the actual factory calibration scenario. With the proposed phase tracking and dynamic-range suppressing phase matrix, the measurement time to characterize gains and phases of 256 elements takes less than 2.3 ms.