Design and Development of SPP for Enhanced OAM Beam Performance with High Mode Purity

This work describes the design and analysis of a conical horn antenna that incorporates spiral phase plates (SPP) for producing orbital angular momentum (OAM) beams at Wi-Fi frequencies around 2.4 GHz. The antenna system's performance is determined using SPPs made of different dielectric materials, such as Rogers, polylactic acid (PLA), and FR4. The simulation results show that the suggested design successfully creates OAM beams across all evaluated dielectric materials. However, raising the dielectric constant causes impedance mismatches, which remain within tolerable ranges. The study emphasises the importance of dielectric material selection in achieving optimal impedance matching and system efficiency while still producing hiah-quality OAM waves.