A novel 3D hemispherical reconfigurable antenna with a switchable radiation pattern using Butler matrix

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 [Formula: see text] 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 [Formula: see text] in the upper hemisphere and an azimuthal coverage of about [Formula: see text] in the XY-plane. These results underscore the system's suitability for dynamic wireless communication environments.