A Multi-band Solution for Interacting with Energy-Neutral Devices

TL;DR

This paper presents a dual-band RF wireless power transfer system that enhances energy delivery to IoT devices, combining beam steering and multi-frequency strategies to improve power and positioning accuracy in indoor environments.

Contribution

It introduces a novel multi-band RF WPT approach with beam steering for improved power transfer and positioning, addressing limitations of single-channel rectennas in large-scale IoT.

Findings

Increased power gain demonstrated in indoor tests.

Enhanced positioning rate achieved with hybrid RF-acoustic system.

Effective dual-band strategy reduces interference while boosting energy delivery.

Abstract

RF Wireless Power Transfer (WPT) emerges as a technology for charging autonomous devices, enabling simultaneous power and information transfer. However, with increasing distance, single-input, single-channel rectenna systems are not able to meet the power requirements of large scale IoT applications. In this paper, we tackle this problem on two levels. First, we minimize the energy consumption at the energy-constrained device on three levels. Second, we evolve to a dual-band solution increasing RF WPT. One frequency band is used to provide a base charge to many nodes in a shared transmission. Beam steering, on the other hand, allows for more power hungry operations while introducing as minimal interference as possible. We showcase this method for a hybrid RF-acoustic positioning system. Practical measurements conducted in a multi-antenna indoor testbed (Techtile) show the additional power gain and positioning rate.