Modes generally provide an economical description of waves, reducing complicated wave
functions to finite numbers of mode amplitudes, as in propagating fiber modes and ideal …

Multiple-antenna technologies are advancing toward the development of extremely large
aperture arrays and the utilization of extremely high frequencies, driving the progress of next …

Effective degree of freedom (EDOF) of a multiple-input–multiple-output (MIMO) system
represents its equivalent number of independent single-input–single-output (SISO) systems …

The prospects of using a reconfigurable intelligent surface (RIS) to aid wireless
communication systems have recently received much attention. Among the different use …

With antenna spacing much less than half a wavelength in confined space, holographic
multiple-input multiple-output (HMIMO) technology presents a promising frontier in next …

Starting from first principles of wave propagation, we consider a multiple-input multiple-
output (MIMO) representation of a communication system between two spatially-continuous …

The capacity limits of continuous-aperture array (CAPA)-based wireless communications are
characterized. To this end, an analytically tractable transmission framework is established …

In recent years, thanks to the advances in meta-materials, the concept of continuous-
aperture MIMO (CAP-MIMO) is reinvestigated to achieve improved communication …

The electromagnetic vortex imaging possesses independent orbital angular momentum
(OAM) with orthogonal degrees of freedom (DoFs), which implies the existence of enhanced …

The adoption of large-scale antenna arrays at high-frequency bands is widely envisioned in
the beyond 5G wireless networks. This leads to the near-field regime where the wavefront is …