Electromagnetic Limitations behind Wide-band Holographic Communications

Focusing on the electromagnetic limitations behind wide-band holographic communications, we investigate the embedded element efficiency of infinite regular antenna arrays with non-ideal matching networks. Under practical considerations, the approximated embedded element efficiency is obtained and utilized to calculate the spectral efficiency of a wide-band holographic MIMO system. By numerical simulations, it is shown that the intensity of mutual coupling among array elements varies according to the operating frequency. Moreover, even if non-ideal matching networks are taken into account, element spacing of half wavelength is still the most economical and practical choice of modern communication systems.