Assessment on the Frequency Dependent Performance of Active Phased Arrays for 5G

To enable beamforming using active phased arrays, calibration of the array is a necessity. Typically, the array is assumed to be frequency independent within the frequency band of operation. However, an active phased array antenna will contain frequency dependent components, making the calibration essentially only valid for the center frequency of the frequency band of operation. In this paper, the results of an assessment on the frequency dependency of an active phased array antenna for the 28 GHz 5G band are presented. It is shown that for this active phased array antenna, the EIRP varies less than 1.2 dB within a 400 MHz channel, whereas the side lobe level typically increases several dB.