A New Approach to the Link Budget Concept for an OAM Communication Link

TL;DR

This paper introduces the 'OAM-link pattern' concept for better understanding and evaluating orbital angular momentum-based communication links, providing a new formula for link budget assessment that accounts for wave phase structure.

Contribution

It proposes a novel 'OAM-link pattern' concept and a corresponding link budget formula that better captures the phase characteristics of OAM waves in antenna array communications.

Findings

The 'OAM-link pattern' offers a more accurate depiction of OAM communication links.

The new formula simplifies link budget evaluation for OAM systems.

Proper rephasing yields a classical main lobe pattern in OAM antenna arrays.

Abstract

Following on from the increasing interest for electromagnetic waves carrying Orbital Angular Momentum (OAM), different configurations of antenna systems able to generate such beams have been proposed. However, in our opinion, a traditional radiation pattern approach does not provide the right picture of an OAM-based communication link. For this reason we propose a new general concept, the "OAM-link pattern", which takes into account the peculiar phase structure characterizing these waves. Focusing on OAM transmissions between antenna arrays, we introduce a formula for the link budget evaluation which describes the whole communication link and directly leads to a "classically shaped" main lobe pattern for a proper rephased reception in the case of uniform circular arrays.