A method of testing phased antenna arrays, the method comprising: positioning a phased antenna array including a plurality of antenna elements and a probe antenna of a plurality of probe antennas at relative positions with respect to each other, either the phased antenna array acting as a transmitting antenna and the probe antenna acting as a receiving antenna, or the probe antenna acting as the transmitting antenna and the phased antenna array acting as the receiving antenna; causing the transmitting antenna to radiate a plurality of electromagnetic waves sequentially; causing the phased antenna array to operate, during transmission of each electromagnetic wave of the plurality of electromagnetic waves according to a corresponding configuration scheme, the corresponding configuration scheme defining at least one of a respective set of antenna elements that are active during the transmission of the electromagnetic wave, or a respective set of phase shifts or time delays that are applied to the plurality of antenna elements during the transmission of the electromagnetic wave; receiving, by the receiving antenna, responsive to each radiated electromagnetic wave, a corresponding receive radio frequency signal; determining, for each antenna element of the plurality of antenna elements, corresponding amplitude and phase parameters using the receive RF signals corresponding to the plurality of electromagnetic waves; and determining one or more performance parameters of the phased antenna array using the determined amplitude and phase parameters for the plurality of antenna elements, characterised in that the plurality of probe antennas are operating at different center frequencies and are positioned at a near field location relative to the phased antenna array. positioning a phased antenna array including a plurality of antenna elements and a probe antenna of a plurality of probe antennas at relative positions with respect to each other, either the phased antenna array acting as a transmitting antenna and the probe antenna acting as a receiving antenna, or the probe antenna acting as the transmitting antenna and the phased antenna array acting as the receiving antenna; causing the transmitting antenna to radiate a plurality of electromagnetic waves sequentially; causing the phased antenna array to operate, during transmission of each electromagnetic wave of the plurality of electromagnetic waves according to a corresponding configuration scheme, the corresponding configuration scheme defining at least one of a respective set of antenna elements that are active during the transmission of the electromagnetic wave, or a respective set of phase shifts or time delays that are applied to the plurality of antenna elements during the transmission of the electromagnetic wave; receiving, by the receiving antenna, responsive to each radiated electromagnetic wave, a corresponding receive radio frequency signal; determining, for each antenna element of the plurality of antenna elements, corresponding amplitude and phase parameters using the receive RF signals corresponding to the plurality of electromagnetic waves; and determining one or more performance parameters of the phased antenna array using the determined amplitude and phase parameters for the plurality of antenna elements, characterised in that the plurality of probe antennas are operating at different center frequencies and are positioned at a near field location relative to the phased antenna array.