Let's Do the Twist!: Radiators, Experiments, and Techniques to Generate Twisted Waves at Radio Frequencies

With the development of fifth-generation (5G) network solutions and high-data communication systems, millimeter-wave frequencies are being proposed for their licensing and bandwidth benefits. E-band radios at 71-76 and 81-86 GHz have recently been developed for backhaul and fixed point-to-point applications. Typically highgain, waveguide-based antennas are used in these deployments. By utilizing polarization, data rates can be increased two-fold. Another way to increase data rates for communication systems on the hardware side is through introducing orbital angular momentum (OAM). By twisting beams, multiple orthogonal modes can travel along the same wireless channel on the same frequency. This article highlights radiators, experiments, and techniques to generate twisted waves at radio frequency (RF).