Wireless Power Transfer via Radiowaves [Hardcover]

Recent advances in Wireless Power Transmission (WPT) technologies have enabled various engineering applications with potential product implementation. WPT can be utilized to charge batteries in various pieces of equipment without the need for a wired connection. Energy can be harvested from ambient RF and microwave radiation and 1 million kW microwaves can be transmitted from space to the ground.
This book covers all the theory and technologies of WPT, such as microwave generators with semi-conductors and microwave tubes, antennas, phased arrays, beam efficiency, and rectifiers (rectenna). The authors also discuss coupling WPT. Applications, such as energy harvesting, sensor networks, point-to-point WPT, WPT to moving targets (airplane, vehicle, etc.) and Solar Power Satellite are also presented.

Introduction ix

Chapter 1. History, Present and Future of WPT 1

1.1. Theoretical predictions and the first trial in the 19th Century 1

1.2. Rejuvenated WPT by microwaves in the 1960s 3

1.3. Inductive coupling WPT projects in the 20th Century 10

1.4. WPT as a game-changing technology in the 21st Century 12

Chapter 2. Theory of WPT 21

2.1. Theoretical background 21

2.2. Beam efficiency and coupling efficiency 22

2.2.1. Beam efficiency of radiowaves 22

2.2.2. Theoretical increase of beam efficiency 26

2.2.3. Coupling efficiency at very close coupling distance 31

2.3. Beam forming 33

2.3.1. Beam-forming theory for the phased array and its error 33

2.3.2. Target detecting via radiowaves 42

2.4. Beam receiving 47

Chapter 3. Technologies of WPT 53