Figure 4
The Design of Time Delay.
(a) The delays of the 8 antennas elements for the generation of the OAM + 1 and OAM-1 beams. (b) The delays for the 8 antennas elements for the steering of the beams. The bottom two panels show the delays applied to the 8 antennas elements for the simultaneous generation and steering of the OAM + 1 (c) and OAM-1 beams (d). Tc: the period of the carrier wave. In practice, only positive delays were implemented so that the element with the most negative delay (A3) was considered a reference, having zero delay, and all other elements were assigned relative delays according to the figures above.
