A Dual-Steerable-Beam Multi-Slot Coupled Metasurface Antenna

This manuscript proposes a dual-steerable-beam multi-slot coupled metasurface antenna for a potential candidate of the indoor base station application. It consists of 7×10 metasurface cells coupled by 4 unequal-spacing slots with a two-port microstrip feeding line. The steerable beams are readily obtained by applying some phase differences between adjacent coupling slots. As a result, the operating band of the proposed antenna ranges from 5.15 GHz to 5.35 GHz for applications of LTE-U band in China. The 10-dB beamwidth of the two beams is around 120° in YOZ plane and the cross level at the junction of the two beams is around -10 dB. Compared with conventional multi-beam antenna arrays, the proposed antenna implements two steerable beams without complex beam-forming network or phase shifters, which can be easily extended to multi-beam indoor base station array design.