Coherently Enhanced Wireless Power Transfer
Artikel i vetenskaplig tidskrift, 2018

Extraction of electromagnetic energy by an antenna from impinging external radiation is at the basis of wireless communications and wireless power transfer (WPT). The maximum of transferred energy is ensured when the antenna is conjugately matched, i.e., when it is resonant and it has an equal coupling with free space and its load. This condition, however, can be easily affected by changes in the environment, preventing optimal operation of a WPT system. Here, we introduce the concept of coherently enhanced WPT that allows us to bypass this difficulty and achieve dynamic control of power transfer. The approach relies on coherent excitation of the waveguide connected to the antenna load with a backward propagating signal of specific amplitude and phase. This signal creates a suitable interference pattern at the load resulting in a modification of the local wave impedance, which in turn enables conjugate matching and a largely increased amount of extracted energy. We develop a simple theoretical model describing this concept, demonstrate it with full-wave numerical simulations for the canonical example of a dipole antenna, and verify experimentally in both near-field and far-field regimes.

Författare

A. E. Krasnok

The University of Texas at Austin

Denis Baranov

Moscow Institute of Physics and Technology

Institutionen för fysik

Andrey Generalov

Aalto-Yliopisto

S. Li

ITMO University

Andrea Alu

The University of Texas at Austin

City University of New York

Physical Review Letters

0031-9007 (ISSN) 1079-7114 (eISSN)

Vol. 120 14 143901

Ämneskategorier

Atom- och molekylfysik och optik

Annan fysik

Annan elektroteknik och elektronik

DOI

10.1103/PhysRevLett.120.143901