Towards Near-Field 3D Spot Beamfocusing: Possibilities, Challenges, and Use-cases

TL;DR

This paper explores the potential and challenges of near-field electronically reconfigurable spot beamfocusing (ER-SBF) for 6G wireless networks, highlighting its applications, technologies, and future research directions.

Contribution

It provides a comprehensive analysis of ER-SBF concepts, antenna technologies, ML-based schemes, and practical applications in next-generation wireless systems, especially for nonoptical frequencies.

Findings

ER-SBF can significantly enhance 6G wireless applications.

Various antenna technologies enable ER-SBF implementation.

ML schemes can facilitate CSI-independent ER-SBF.

Abstract

Spot beamfocusing (SBF) is the process of focusing the signal power in a small spot-like region in the 3D space, which can be either hard-tuned (HT) using traditional tools like lenses and mirrors or electronically reconfigured (ER) using modern large-scale intelligent surface phased arrays. ER-SBF can be a key enabling technology (KET) for the next-generation 6G wireless networks offering benefits to many future wireless application areas such as wireless communication and security, mid-range high-power and safe wireless chargers, medical and health, physics, etc. Although near-field HT-SBF and ER-beamfocusing have been studied in the literature and applied in the industry, there is no comprehensive study of different aspects of ER-SBF and its future applications, especially for nonoptical (mmWave, sub-THz, and THz) electromagnetic waves in the next generation wireless technology, which is the aim of this paper. The theoretical concepts behind ER-SBF, different antenna technologies for implementing ER-SBF, employing machine learning (ML)-based schemes for enabling channel-state-information (CSI)-independent ER-SBF, and different practical application areas that can benefit from ER-SBF will be explored.