Multistate Planar OAM Antenna for Reduced Inter-Modal Interference

Orbital angular momentum (OAM) is a new dimension of modulation for significant enhancement of the data communication rates within the given spectrum. OAM carried by an EM wave is associated with its characteristic phase variation in space, leading to orthogonality of each wave. Since this technology is now at an early developmental stage, there are several challenges in practically achieving the desired outcomes. This paper presents an OAM Wi-Fi (2.4 GHz) antenna capable of producing up to five (three simultaneous) orthogonal OAM states using a simple planner design. Additionally, a new approach to reduce inter-modal interference in line-of-sight OAM links has also been proposed and has been presented showing up to 9dB of isolation without any physical modification. Three different feed network designs are also included to, and one is discussed in detail for compliance with the demodulation requirements.