Utilization of photon orbital angular momentum in the low-frequency radio domain

TL;DR

This paper demonstrates numerically that low-frequency radio beams can carry orbital angular momentum using vector antenna arrays, enabling new experiments and applications in radio physics and wireless communication.

Contribution

It introduces a method to generate and measure radio beams with spin and orbital angular momentum at low frequencies using digital techniques.

Findings

Radio beams with angular momentum characteristics are numerically demonstrated.

Digital measurement and manipulation of local field vectors are feasible at <1 GHz.

Potential for new experiments and applications in radio astronomy and wireless communication.

Abstract

We show numerically that vector antenna arrays can generate radio beams which exhibit spin and orbital angular momentum characteristics similar to those of helical Laguerre-Gauss laser beams in paraxial optics. For low frequencies (< 1 GHz), digital techniques can be used to coherently measure the instantaneous, local field vectors and to manipulate them in software. This opens up for new types of experiments that go beyond those currently possible to perform in optics, for information-rich radio physics applications such as radio astronomy, and for novel wireless communication concepts.