The EMC of Orbital Angular Momentum (OAM) Based Wireless Communication

In recent years, the interest in the usage of orbital angular momentum (0AM) modes in wireless communication increased and the corresponding research on the integration of 0AM modes into modern communication systems has started. 0AM promises to increase the data rate by using the modes as multiple independent communication channels. The fields of the different 0AM modes are characterized by their spiral phase pattern, which differs from that of plane waves. 0AM modes used in wireless communication are orthogonal, meaning they can be excited and received independently in certain environments, which promises better utilization of the spatial dimension. However, 0AM-based communication is shown to be strongly susceptible to interference, refection and symmetry disruptions, requiring knowledge in and a careful consideration of the EMC of these systems. In this context, this contribution discusses the differences between 0AM modes and conventional antennas and waves in classical EMC issues such as shielding and interference and highlights the crosstalk between 0AM modes resulting from geometric asymmetries. To appropriately design an 0AM-based communication and solve its EMC problems, the main lessons learned are summarized and their practical implications are discussed.