Power-efficient Near-field Focusing for Upcoming 6G MIMO Networks

An accurate and efficient near-field intensity shaping method is proposed, capable of reproducing sharp patterns while simplifying the design requirements of the array's feeding network. The shaping problem is tackled by an efficient farto-near-field transform, based on a spherical Fourier transform and multipole expansion of active radiation patterns, including mutual coupling effects. By limiting field levels outside the focussing region and by steering phases only, a power and costeffective field shaping method is obtained. The added value of the advocated method is proven for the upcoming sixth-generation wireless networks with phase-only near-field shaping.