Wireless Power Transfer via Radiowaves

Chapter 4

Applications of WPT

4.1. Introduction

The following are descriptions of some of the main features of suitable applications of wireless power transmission (WPT) via radiowaves, especially microwave power transmission (MPT).

1) MPT using diffused radiowaves: MPT for multiusers using diffused radiowaves or energy harvesting from broadcasting waves (long-distance power transfer) (sections 4.2–4.4):

– similar wireless systems as used for information systems but with greater considerations for efficiency;

– coexistence of diffused wireless power and wireless communication;

– ubiquitous (everywhere and anytime) power source;

– possibility of utilization of lower frequencies with higher conversion efficiency because the radiowave source is diffused and is not a beam system;

– research topics: smaller size, large aperture antennas and high-efficiency low-frequency rectifiers.

2) MPT in a closed system or shorter distance MPT systems (sections 4.5–4.8):

– high-efficiency transmission with small antenna sizes over short distances or through closed waveguides;

– minimum unexpected radiation;

– free positioning of the transmitters and the receivers because of no coupling between the transmitters and the receivers;

– possibility of utilizing lower frequencies with higher efficiency;

– research topic: higher power semiconductors.

3) MPT using a beamed radiowave: MPT to a moving target from a transmitter (long distance power transfer) (sections 4.8–4.10):

– impossible to accomplish ...