Beamforming Techniques for Large-N Aperture Arrays

TL;DR

This paper discusses hierarchical beamforming techniques for large-N aperture arrays, comparing RF and digital approaches through implementations on two demonstrator arrays, focusing on efficiency and technology-agnostic structures.

Contribution

It introduces a hierarchical, technology-agnostic beamforming framework and compares RF and digital implementations on real large-scale antenna arrays.

Findings

Hierarchical beamforming is effective for large-N arrays.

Digital and RF beamforming implementations are feasible on existing arrays.

The approach is adaptable to future semiconductor and processing developments.

Abstract

Beamforming is central to the processing function of all phased arrays and becomes particularly challenging with a large number of antenna element (e.g. >100,000). The ability to beamform efficiently with reasonable power requirements is discussed in this paper. Whilst the most appropriate beamforming technology will change over time due to semiconductor and processing developments, we present a hierarchical structure which is technology agnostic and describe both Radio-Frequency (RF) and digital hierarchical beamforming approaches. We present implementations of both RF and digital beamforming systems on two antenna array demonstrators, namely the Electronic Multi Beam Radio Astronomy ConcEpt (EMBRACE) and the dualpolarisation all-digital array (2-PAD). This paper will compare and contrast both digital and analogue implementations without considering the deep system design of these arrays.