Narrow Beamforming in Non-Terrestrial 5G/6G Networks: Is it Possible?

This article explores beamforming in 5G/6G radio coverage, with a focus on satellite-based non-terrestrial networks (NTNs). It discusses the challenges of applying phased-array antenna technologies, which are vital for achieving narrow beamforming in both 5G/6G terrestrial networks (TNs) and NTNs. We highlight advancements in material technologies that enable the creation of compact and powerful massive Multi-Input Multi-Output (mMIMO) antennas, introducing nano-antenna arrays (e.g., $1024 \times 1024$ elements) that occupy $1 \mathrm{~mm}^{2}$ at terahertz frequencies ($1-10 \mathrm{THz}$). We also detail how applying mMIMO antenna arrays in space offers new potential for achieving narrow beamforming in satellite-based 5G/6G NTNs. We investigate the ongoing efforts in deploying such mMIMO in space to replicate the cellular radio coverage of TNs.