Overlapping Direct Radiating Arrays with an Interleaved Layer of Tiles for Satellite Communications

Hybrid beamforming schemes have been welcomed in the past years as a prolific way to reduce the digital complexity of direct radiating arrays. Nevertheless, such cascade of analog and digital beamforming implies the addition of interfering grating lobes, considered as highly problematic in broadband satellite communications. Overlapping is seen as a solution and has emerged in the literature as an efficient technique to partially mitigate some or all these unwanted lobes. Often, it guarantees strong performances by increasing the analog complexity and is limited by the hardware implementation on-board the satellite. A solution is proposed in the abstract that avoids such limitations. An additional layer of tiles shifted by half the size of a sub array along 2-D is interleaved with the classic hybrid beamforming scheme. The advantages and drawbacks of the methodology are discussed.