A metasurface based low-profile reconfigurable antenna with pattern diversity

A low-profile reconfigurable antenna with a capability of generating multidirectional beams is presented in this paper. The design consists of a 4 x 4 unit cells metasurface (MS), a four-slotted ground plane, and a reconfigurable feeding network. By offsetting the slots from the center of MS, the unit cells of the MS can be excited with different phases and the main beam of the antenna can be steered to the desired direction. The pattern reconfigurablility is conveniently accomplished by electrically controlling the ON/OFF states of four p-i-n diodes on the feeding network to excite the proper slot. The final antenna has low profile of 0.042 lambda(0) at the center operating frequency. The measurement indicates that the antenna has wide operating band of 10.4% by combining two adjacent resonances generated by the slot and the MS. Besides, the antenna exhibits four distinct beams with a peak gain value of 5.6 dBi. It is worth to note that compared to other pattern reconfigurable antennas in literature, the proposed design has advantages of low profile, wide operating bandwidth, and small number of p-i-n diodes. (C) 2019 Elsevier GmbH. All rights reserved.