Side Effects of Triangular-Grid Geometry and Orientation in Hierarchical Regular Subarray-Based Large-Scale Digital Antenna Arrays

While hierarchical subarray-based architectures are widely adopted for computational efficiency, the side effects of subarray management on the array factor and overall radiation behaviour remains insufficiently addressed. Array grid and perimeter misalignment with the subarrays can cause side effects such as increased sidelobe levels and distorted beam shapes. By implementing well-oriented, periodic subarray distributions, we show how one can achieve improved radiation performance, enhanced beam symmetry, and reduced sidelobe interference. We establish clear cause–effect relationships between subarray orientation, edge structure, and the resulting radiation patterns. Simulation results demonstrate that precise geometric alignment of subarrays leads to better energy concentration and consistent array factors. Our design approach is highly suitable for scalable, fully digital beamforming systems.