Error Analysis of Programmable Metasurfaces for Beam Steering

Abstract

Recent years have seen the emergence of programmable metasurfaces, where the user can modify the EM response of the device via software. Adding reconfigurability to the already powerful EM capabilities of metasurfaces opens the door to novel cyber-physical systems with exciting applications in domains such as holography, cloaking, or wireless communications. This paradigm shift, however, comes with a non-trivial increase of the complexity of the metasurfaces that will pose new reliability challenges stemming from the need to integrate tuning, control, and communication resources to implement the programmability. While metasurfaces will become prone to failures, little is known about their tolerance to errors. To bridge this gap, this paper examines the reliability problem in programmable metamaterials by proposing an error model and a general methodology for error analysis. To derive the error model, the causes and potential impact of faults are identified and discussed qualitatively. The methodology is presented and exemplified for beam steering, which constitutes a relevant case for programmable metasurfaces. Results show that performance degradation depends on the type of error and its spatial distribution and that, in beam steering, error rates over 20% can still be considered acceptable.

Radiation Pattern Prediction for Metasurfaces: A Neural Network-Based Approach

“…It is important to state that, the numbers can vary depending on the dimension of MSF and configuration of NNs, but the order of magnitude will remain similar. Moreover, this has been corroborated by multiple studies such as [ 40 , 41 , 42 ]. For a more in-depth analysis into the computational complexity of NNs, analytical methods, and full-wave simulators, we refer the reader to Appendix B .…”

Smart Radio Environments Empowered by Reconfigurable Intelligent Surfaces: How It Works, State of Research, and The Road Ahead

“…Several research papers on the design of software-defined metamaterials and nano-communication networks for application to metasurfaces have recently appeared in the literature. The research issues tacked in these papers encompass the definition of softwaredefined primitives, the analysis of communication and security issues, the design of medium access control protocols, routing protocols, and the network layer configuration and operation [259], [260], [261], [262], [263], [264], [265]. Interested readers are referred to [56] for further information.…”

Toward Fault-Tolerant Deadlock-Free Routing in HyperSurface-Embedded Controller Networks

“…9 which depicts unreachable node sums (i.e., faulty, victimized and FB boundary) as a function of faulty node counts, for the RF and CF scenarios 3 . It is observed that at an average 1.6% total faulty nodes, 66% and 76% of all nodes are spanned by the proposed FT algorithm under the respective RF and CF scenarios; these values constitute acceptable HSF functionality that is tolerant to some directives loss [12]. Moreover, Fig.…”

“…Such HSFs must safeguard against faults during fabrication, deployment, or operation, which have been shown to degrade HSF performance and are caused by factors such as connector misalignment, ageing, physical or intentional damage of unit cells, etc. [12]. As such, to establish dependable communication among interconnected controllers in an HSF structure, we propose a link-level Fault-Tolerant (FT) routing algorithm that arms routed packetized directives 1 , that reconfigure EM properties of meta-atoms in the HSF, in bypassing faulty nodes on their way to their destination controllers.…”