An Intermodulation Distortion Oriented 256-Element Phased-Array Calibration for 5G Base Station

A novel phased-array calibration method is presented. The amplitude and the phase of intermodulation distortion emitted from multiple antenna elements are characterized simultaneously with those of main signal. Phase shifters of elements are modulated with an orthogonal code and a 3-tone (2 fixed-frequency tones and a chirp) signal is applied to enable simultaneous characterization. The method is demonstrated using 256-element phased-array antennas for 5G millimeter-wave base station. The characterization of 256 elements is done with 2.3 ms of measurement.