Uniform Linear Arrays with Hybrid Beamforming: To Overlap or Not To Overlap?

Overlapping strategies for hybrid beamformed direct radiating arrays have been studied in the past decades as a means to improve the gain of a directive beam. It is widely known that overlapping subarrays guarantees the suppression or the partial mitigation of some unwanted grating lobes. However, such techniques come with a cost, either in terms of hardware or in terms of digital complexity. Performance-wise, the overlapping strategies have also shown particular cases where the scanning improvements were not evident. This paper presents a study of the general overlapping principles in hybrid analogue-digital beamformed direct radiating arrays for the case of a GEO satellite application. This study allows to identify cases where the overlapping technique is beneficial compared to a non-overlapped array.