Park, WoocheonWoocheonParkWang, LeiLeiWangBrüns, Heinz-DietrichHeinz-DietrichBrünsKam, Dong GunDong GunKamSchuster, ChristianChristianSchuster2019-04-042019-04-042019-03IEEE Transactions on Antennas and Propagation 3 (67): 1719-1728 (2019-03)http://hdl.handle.net/11420/2270This paper introduces a mixed-mode matrix representation of scattering parameters that is suitable for the investigation of wireless communication based on orbital angular momentum (OAM). For this purpose, a unitary transformation matrix is defined, which contains the transmitted and received amplitudes as basis vectors corresponding to OAM-based communication between two antenna arrays. The mixed-mode matrix is then obtained from the corresponding similarity transformation of the standard scattering matrix available, e.g., from numerical simulations or measurements. The mixed-mode matrix allows better physical insight into OAM-based communication by clearly separating all modes and is more efficient than postprocessing of single-antenna results in a system simulator. Mode conversion/isolation and proper mode termination can be easily quantified. Also, it allows generalizing the interpretation of OAM-based communication by focusing on the property of a constant phase difference within each antenna array. The usefulness of this approach is demonstrated using method of moments (MoM) simulations of dipole radiators in various arrangements of a transmitting and a receiving array. Systematic parameter studies that reveal dependencies of OAM-based communication are possible by using the mixed-mode matrix. As an application, communication patterns are studied, in order to obtain the suitable position and relative orientation in space for good mode isolation or communication. © 1963-2012 IEEE.en0018-926X2019317191728Journal Article10.1109/TAP.2018.2889033Other