Analysis of Coupling Coefficient Between Two UCA-OAM Antennas Based on Infinitesimal Dipole Modeling

An infinitesimal dipole modeling (IDM)-based analysis method is proposed to calculate the coupling coefficient (CC) between two uniform circular array (UCA)-orbital angular momentum (OAM) antennas. The proposed method is demonstrated to be more accurate than the asymptotic expression while also being more computationally efficient compared to the method of moments (MoM)-based full-wave simulation. Moreover, the proposed method enables CC analysis between UCAs operating in different OAM modes or in the presence of misalignment. The proposed method can potentially be utilized to estimate channel coefficients electromagnetically and to design OAM communication systems.