# On the Deployment of Multiple Radio Stripes for Large-Scale Near-Field RF Wireless Power Transfer

## TL;DR

This paper explores deploying multiple radio stripes for indoor near-field RF wireless power transfer, proposing algorithms for optimal placement to maximize power delivery to hotspots, with various deployment shapes and methods tested.

## Contribution

It introduces a joint clustering and deployment optimization framework for radio stripes, including four novel algorithms and shape-constrained solutions for efficient large-scale RF wireless power transfer.

## Key findings

- Optimized deployments outperform benchmarks across frequencies and lengths.
- Polygon-shaped deployment yields better performance than other shapes.
- Line-shaped deployment excels under high boresight gain conditions.

## Abstract

This paper investigates the deployment of radio stripe systems for indoor radio-frequency (RF) wireless power transfer (WPT) in line-of-sight near-field scenarios. The focus is on environments where energy demand is concentrated in specific areas, referred to as 'hotspots', spatial zones with higher user density or consistent energy requirements. We formulate a joint clustering and radio stripe deployment problem that aims to maximize the minimum received power across all hotspots. To address the complexity, we decouple the problem into two stages: i) clustering for assigning radio stripes to hotspots based on their spatial positions and near-field propagation characteristics, and ii) antenna element placement optimization. In particular, we propose four radio stripe deployment algorithms. Two are based on general successive convex approximation (SCA) and signomial programming (SGP) methods. The other two are shape-constrained solutions where antenna elements are arranged along either straight lines or regular polygons, enabling simpler deployment. Numerical results show that the proposed clustering method converges effectively, with Chebyshev initialization significantly outperforming random initialization. The optimized deployments consistently outperform baseline benchmarks across a wide range of frequencies and radio stripe lengths, while the polygon-shaped deployment achieves better performance compared to other approaches. Meanwhile, the line-shaped deployment demonstrates an advantage under high boresight gain settings, benefiting from increased spatial diversity and broader angular coverage.