Experimental demonstration of 16-Gbit/s millimeter-wave communications link using thin metamaterial plates to generate data-carrying orbital-angular-momentum beams

We present the design and performance characterization of a thin metamaterial plate for generation of orbital angular momentum (OAM) modes of a millimeter-wave beam, which can carry independent data streams over the same physical medium. The plate has a thickness of 1.56 mm, and consists of 3.06 × 0.68 mm rectangular apertures with spatial variant orientations. It generates OAM beams l = +1 and l = +3 with mode purity larger than 77.5% over a bandwidth of 6 GHz (25–31 GHz). We then use these streams to experimentally demonstrate a 16-Gbit/s millimeter-wave wireless communications link using two multiplexed OAM modes, each carrying a 2-Gbaud 16-QAM signal. A channel crosstalk less than −20 dB over a bandwidth of 4 GHz (26–30 GHz) and biterror-rates (BER) less than 3.8 × 10⁻³ are achieved.