Linear Antenna Array With Full-Spherical Beamsteering

This article presents a linear array that provides full-spherical beamsteering. A pattern-reconfigurable (PR) element is designed, comprising a dipole surrounded by switchable patches, which can be configured to be either reflective or transparent to incident waves. In this way, the main beam can be pointed toward different directions within a 360° range in the elevation plane. To steer the beam in the azimuth plane, a linear array is synthesized. Metallic baffles are used to separate the elements, thus simultaneously reducing the mutual coupling and widening the element pattern. Even higher levels of isolation are accomplished by introducing dielectric walls. Owing to the 163°-wide element beamwidth and to the low mutual coupling conditions, the array achieves ultra-wide-angle scanning of ±81°, with a maximum realized gain of 16.3 dBi, a scan loss of around 3 dB, and an active reflection coefficient below −10 dB. The combination of the 360° steering range provided by the individual element in the elevation plane, with the wide-angle scanning performance of its array structure in the azimuth plane, yields the desired full-spherical coverage. A prototype is fabricated, and the measurements are in good agreement with the simulations. Potential applications include vehicular sensing and communication systems operating in ever-changing environments.