Intermodulation Effects and System Sensitivity Degradation in 5G Phased-Arrays Due to Multiple Interferers

Electronically-scanned phased arrays are an integral part of millimeter-wave 5G networks, and therefore, it is important to examine the effects of interferers on the performance of a receiving phased-array. This paper presents both theoretical analysis and experimental verification of IM3 effects in a 28 GHz 5G phased array operating in the receive mode. It is shown that the intermodulation products generated by interferers peak at certain predictable scan angles depending on their direction of arrival and can limit the sensitivity of the phased array. The interferers degrade the phased-array sensitivity even if present in the direction of pattern nulls. Theoretical predictions are verified by numerical code and measurement results for multiple interferers from different directions.