Diagnostics of the Phased Array for E-Band Using Holography Data

This paper presents antenna diagnostics of a 4 by 4 phased antenna array for 71–86 GHz, which could be potentially used as a future 5G access point. The antenna elements have their own phase shifters each and are fed from the one-port feeding network, which results in a challenge in single element performance analysis. To overcome this, the antenna has been measured with a near-field scanner and the acquired data is processed to form the holography presentation of the antenna radiation at its very aperture. The hologram results are further handled to analyze the phase shifters of each element and the operation of the feeding network over the observed frequency range. The mean amplitude and phase for the each element are calculated and the results are verified by calculation of the far-field using the processed values and compared to the far-field measurement results. The results show good agreement and the phase shifters work as intended resulting in the antenna beam steering accordingly. However, the feeding network is quite frequency-sensitive and it leaves much improvement especially for the 75–82 GHz band.