Wireless Power Transfer with Distributed Antennas: System Design, Prototype, and Experiments

TL;DR

This paper presents a novel distributed antenna system for wireless power transfer that dynamically selects antennas and frequencies, significantly boosting power output and coverage in real indoor environments.

Contribution

It introduces a low-complexity, flexible WPT DAS architecture with joint spatial and frequency diversity exploitation, including a practical prototype and real-world experiments.

Findings

Up to 30 dB power boost in single-user scenarios

Up to 21.8 dB power increase in two-user scenarios

Broadened service coverage area in indoor environments

Abstract

In this paper, we design and experiment a far-field wireless power transfer (WPT) architecture based on distributed antennas, so-called WPT DAS, that dynamically selects transmit antenna and frequency to increase the output dc power. Uniquely, spatial and frequency diversities are jointly exploited in the proposed WPT DAS with low complexity, low cost, and flexible deployment to combat the wireless fading channel. A numerical experiment is designed to show the benefits using antenna and frequency selections in spatially and frequency selective fading channels for single-user and multi-user cases. Accordingly, the proposed WPT DAS for single-user and two-user cases is prototyped. At the transmitter, we adopt antenna selection to exploit spatial diversity and adopt frequency selection to exploit frequency diversity. A low-complexity over-the-air limited feedback using an IEEE 802.15.4 RF interface is designed for antenna and frequency selections and reporting from the receiver to the transmitter. The proposed WPT DAS prototype is demonstrated in a real indoor environment. The measurements show that WPT DAS can boost the output dc power by up to 30 dB in single-user case and boost the sum of output dc power by up to 21.8 dB in two-user case and broaden the service coverage area in a low cost, low complexity, and flexible manner.