In this paper, we present a compact three-dimensional hemispherical reconfigurable antenna system designed for 5G networks operating around 3.6 GHz. The proposed architecture combines a four-element Vivaldi antenna array with a passive \(4\times 4\) Butler matrix to enable electronically switchable beams in three main directions: upward, rightward, and backward. Beam steering is achieved through a simple PIN diode switching network, eliminating the need for active phase control. Experimental measurements and full-wave simulations confirm consistent directivity and wide angular coverage, with an elevation coverage of approximately \(115^\circ\) in the upper hemisphere and an azimuthal coverage of about \(227^\circ\) in the XY-plane. These results underscore the system’s suitability for dynamic wireless communication environments.
