Wireless signals look different when observed near to versus far from the transmitter. The notions of near and far also depend on the physical size of the transmitter and receiver, as well as on the wavelength. In this episode, Erik G. Larsson and Emil Björnson discuss these fundamental phenomena and how they can be utilized when designing future communication systems. Concept such as near-field communications, finite-depth beamforming, mutual coupling, and new spatial multiplexing methods such as orbital angular momentum (OAM) are covered. To get more technical details, you can read the paper “A Primer on Near-Field Beamforming for Arrays and Reconfigurable Intelligent Surfaces” (https://arxiv.org/pdf/2110.06661.pdf). Music: On the Verge by Joseph McDade. Visit Erik’s website https://liu.se/en/employee/erila39 and Emil’s website https://ebjornson.com/